Validity of bipolar disorder hospital discharge diagnoses: file review and multiple register linkage in Sweden

The predictive effect of family genetic risk scores as an indirect measure of causal effects of one disorder on another

BACKGROUND

One potential cause of comorbidity is the direct causal effect of one disorder - A - on risk for subsequent onset of disorder B. Could genetic risk scores be utilized to test for such an effect? If disorder A causally impacts on risk for disorder B, then genetic risk for disorder A should be lower in cases of disorder A with v. without a prior onset of B.

METHODS

In all individuals (n = 905 736) born in Sweden from 1980 to 1990, from six psychiatric and drug use disorders (major depression, anxiety disorders, alcohol use disorder, drug use disorder, bipolar disorder, and schizophrenia), we formed 14 pairs of disorders A and B. In these pairs, we compared, using Cox proportional hazards models, the predictive effect of the familial-genetic risk score (FGRS) for disorder B in those who had v. had not had a prior onset of disorder A.

RESULTS

In all pairs, the impact of the FGRS for disorder B was significantly stronger in cases without v. with a prior history of disorder A. These effects were similar across sex, stable across levels of FGRS and not likely due to clinician bias. In many of our disorder pairs, previous clinical studies suggest a mechanism for a causal effect of disorder A on B.

CONCLUSIONS

Our findings provide indirect evidence that the occurrence of one psychiatric or substance use disorder often has a causal effect on risk for subsequent disorders. This mechanism may substantially contribute to the widespread comorbidity among psychiatric conditions.

Childhood and adolescence outcomes in offspring to parents with bipolar disorder: the impact of lifetime parental comorbidity, parental sex, and bipolar subtype

BACKGROUND

Offspring of parents with bipolar disorder have increased risks of their own psychopathology. However, a large-scale survey of psychiatric, somatic, and adverse social outcomes up to adulthood, which could aid in prioritizing and tailoring prevention, is lacking. It also remains to clarify how risks are modified by other parental factors.

METHODS

Swedish population registers were linked to compare offspring having (N = 24,788) and not having (N = 247,880) a parent with bipolar disorder with respect to psychiatric diagnoses and psychotropic medication, birth-related and somatic conditions, social outcomes, accidents, suicide attempts, and mortality. Individuals were followed until age 18. We estimated the influence of lifetime parental psychiatric comorbidity, bipolar disorder subtype, and sex on outcomes.

RESULTS

Children of parents with bipolar disorder had 2-3 times higher risks of all psychiatric diagnoses, except for bipolar disorder, for which the risk was 11-fold. Significantly increased risks were also found for several somatic conditions, low school grades, criminal behavior, victimization, accidents, and suicidal behavior. Adjusting for lifetime parental psychiatric comorbidity attenuated most associations. Offspring of a parent with bipolar disorder type 2 had statistically significantly higher risks of attention deficit hyperactivity disorder, respiratory tract conditions, and accidents compared with offspring of a parent with bipolar disorder type 1. Offspring of mothers with bipolar disorder had higher risks of several psychiatric diagnoses, respiratory tract conditions, low school grades, and accidents compared with offspring of fathers with bipolar disorder. Having two parents with bipolar disorder entailed the highest risks of psychiatric outcomes in offspring.

CONCLUSIONS

Early intervention and family support are particularly warranted for the offspring of a parent with bipolar disorder in the presence of lifetime parental psychiatric comorbidity, when the parent has bipolar disorder type 2, or when the mother or both parents have bipolar disorder.

COVID-19-associated mortality in individuals with serious mental disorders in Sweden during the first two years of the pandemic- a population-based register study

BACKGROUND

Reports at the beginning of the COVID-19 pandemic suggested differences in COVID-19-associated mortality between individuals with serious mental disorders (SMD) and the population at large.

AIM

To compare the pattern of COVID-19-associated mortality in individuals with and without SMD in Sweden over the two main pandemic years.

METHODS

We compared the pattern of COVID-19-associated mortality in individuals with and without SMD in Sweden during 2020 and 2021. For SMD, we included psychotic disorder, bipolar disorder, and severe depression. The analysis was based on summary data from the Swedish Board of Health and Welfare covering the entire adult Swedish population.

RESULTS

The overall relative risk (RR) for experiencing a COVID-19-associated death was 1.66 (CI 1.50-1.83; p < 0.001) for individuals with SMD versus individuals without SMD. The corresponding RRs were 3.25 (CI 2.84-3.71; p < 0.001) for individuals with psychotic disorder, 1.06 (CI 0.88-1.26; p = 0.54) for individuals with bipolar disorder, and 1.03 (CI 0.80-1.32; p = 0.80) for individuals with severe depression. Compared to their respective counterparts in the non-SMD group, in the psychotic disorder and severe depression group, the RR were higher in women than in men. In the bipolar disorder group, the RR was higher in men than in women. The RR of COVID-19-associated death was generally higher in younger individuals with SMD. Individuals with psychosis between 18 and 59 years had the highest RR of COVID-19-associated death with 7.25 (CI 4.54-11.59; p<0.001).

CONCLUSIONS

Individuals with SMD, and particularly those with psychotic disorders, had a higher risk of COVID-19-associated death than the general population. As this is a pattern also seen with other infections, people with SMD may be similarly vulnerable in future pandemics.

The bidirectional association between premenstrual disorders and perinatal depression: A nationwide register-based study from Sweden

BACKGROUND

Premenstrual disorders (PMDs) and perinatal depression (PND) share symptomology and the timing of symptoms of both conditions coincide with natural hormonal fluctuations, which may indicate a shared etiology. Yet, there is a notable absence of prospective data on the potential bidirectional association between these conditions, which is crucial for guiding clinical management. Using the Swedish nationwide registers with prospectively collected data, we aimed to investigate the bidirectional association between PMDs and PND.

METHODS AND FINDINGS

With 1,803,309 singleton pregnancies of 1,041,419 women recorded in the Swedish Medical Birth Register during 2001 to 2018, we conducted a nested case-control study to examine the risk of PND following PMDs, which is equivalent to a cohort study, and transitioned that design into a matched cohort study with onward follow-up to simulate a prospective study design and examine the risk of PMDs after PND (within the same study population). Incident PND and PMDs were identified through clinical diagnoses or prescribed medications. We randomly selected 10 pregnant women without PND, individually matched to each PND case on maternal age and calendar year using incidence density sampling (N: 84,949: 849,482). We (1) calculated odds ratio (OR) and 95% confidence intervals (CIs) of PMDs using conditional logistic regression in the nested case-control study. Demographic factors (country of birth, educational level, region of residency, and cohabitation status) were adjusted for. We (2) calculated the hazard ratio (HR) and 95% CIs of PMDs subsequent to PND using stratified Cox regression in the matched cohort study. Smoking, BMI, parity, and history of psychiatric disorders were further controlled for, in addition to demographic factors. Pregnancies from full sisters of PND cases were identified for sibling comparison, which contrasts the risk within each set of full sisters discordant on PND. In the nested case-control study, we identified 2,488 PMDs (2.9%) before pregnancy among women with PND and 5,199 (0.6%) among controls. PMDs were associated with a higher risk of subsequent PND (OR 4.76, 95% CI [4.52,5.01]; p < 0.001). In the matched cohort with a mean follow-up of 7.40 years, we identified 4,227 newly diagnosed PMDs among women with PND (incidence rate (IR) 7.6/1,000 person-years) and 21,326 among controls (IR 3.8). Compared to their matched controls, women with PND were at higher risk of subsequent PMDs (HR 1.81, 95% CI [1.74,1.88]; p < 0.001). The bidirectional association was noted for both prenatal and postnatal depression and was stronger among women without history of psychiatric disorders (p for interaction < 0.001). Sibling comparison showed somewhat attenuated, yet statistically significant, bidirectional associations. The main limitation of this study was that our findings, based on clinical diagnoses recorded in registers, may not generalize well to women with mild PMDs or PND.

CONCLUSIONS

In this study, we observed a bidirectional association between PMDs and PND. These findings suggest that a history of PMDs can inform PND susceptibility and vice versa and lend support to the shared etiology between both disorders.

Environmental risk factors for schizophrenia and bipolar disorder from childhood to diagnosis: a Swedish nested case-control study

BACKGROUND

Shared genetic risk between schizophrenia (SCZ) and bipolar disorder (BD) is well-established, yet the extent to which they share environmental risk factors remains unclear. We compare the associations between environmental exposures during childhood/prior to disorder onset with the risk of developing SCZ and BD.

METHODS

We conducted a Swedish register-based nested case-control study using 4184 SCZ cases and 18 681 BD cases diagnosed 1988-2013. Cases were matched to five controls by birth year, birth region, and sex. Conditional logistic regression was used to estimate incidence rate ratios (IRR) for SCZ and BD for each exposure (severe childhood infections, adverse childhood experiences (ACEs), substance use disorders (SUDs), urban birth/longest residence).

RESULTS

All SUD types were associated with very high risk (IRR 4.9-25.5), and all forms of ACEs with higher risk (IRR 1.5-4.3) for both disorders. In the mutually adjusted models, ACEs demonstrated slightly higher risk for BD (SCZ IRR 1.30, 1.19-1.42; BD IRR 1.49, 1.44-1.55), while for SUD, risk was higher for SCZ (SCZ IRR 9.43, 8.15-10.92; BD IRR 5.50, 5.15-5.88). Infections were associated with increased risk of BD (IRR 1.21, 1.17-1.26) but not SCZ. Urban birth and urban longest residence were associated with higher risk of SCZ (IRR 1.19, 1.03-1.37), while only the combination of urban birth and rural longest residence showed higher risk for BD (IRR 1.24, 1.13-1.35).

CONCLUSIONS

There were both shared and unique environmental risk factors: SUDs and ACEs were risk factors for both disorders, while infections were more strongly associated with BD and urbanicity with SCZ.

The relationship between familial-genetic risk and pharmacological treatment in a Swedish national sample of patients with major depression, bipolar disorder, and schizophrenia

Using Swedish registers, we examine whether the prescription of and the response to antidepressants (AD), mood stabilizers (MS), and antipsychotics (AP) in the treatment of, respectively, major depression (MD), bipolar disorder (BD), and schizophrenia (SZ), are influenced by familial-genetic risk. We examined individuals born in Sweden 1960-1995 with a first diagnosis of MD (n = 257,177), BD (n = 23,032), and SZ (n = 4248) from 2006 to 2018. Drug classes and Defined Daily Dose (DDD) were obtained from the Pharmacy register using the Anatomical Therapeutic Chemical system. We utilized the Familial Genetic Risk Scores (FGRS) calculated from morbidity risks in first- through fifth degree relatives. Treatment with antidepressants (AD) in MD, mood-stabilizers (MS) in BD, and antipsychotics (AP) in SZ were associated with significantly higher disorder-specific familial-genetic risks. Using dosage trajectory analysis of AD, MS, and AP treatment for MD, BD, and SZ, respectively, familial-genetic risk was positively associated with higher and/or increasing drug dosages over time. For MD and BD, examining cases started on the most common pharmacologic treatment class (SSRIs for MD and "other anti-epileptics" for BD), familial-genetic risks were significantly lower in those who did not versus did later receive treatment from other AD and MS classes, respectively. Higher familial-genetic risk for BD predicted switching AD medication in cases of MD. Among pharmacologically treated cases of BD, familial-genetic risk was significantly higher for those treated with lithium. In a large population-based patient cohort, we found evidence of a wide-spread association between higher familial-genetic risk and i) increased likelihood of receiving pharmacologic treatment but 2) responding more poorly to it-as indicated by a switching of medications -- and/or requiring higher doses. Further investigations into the clinical utility of genetic risk scores in the clinical managements of MD, BD, and SZ are warranted.

Dissecting the impact of complement component 4A in bipolar disorder

The genetic overlap between schizophrenia (SZ) and bipolar disorder (BD) is substantial. Polygenic risk scores have been shown to dissect different symptom dimensions within and across these two disorders. Here, we focused on the most strongly associated SZ risk locus located in the extended MHC region, which is largely explained by copy numbers of the gene coding for complement component 4A (C4A). First, we utilized existing brain tissue collections (N = 1,202 samples) and observed no altered C4A expression in BD samples. The generated C4A seeded co-expression networks displayed no genetic enrichment for BD. To study if genetically predicted C4A expression discriminates between subphenotypes of BD, we applied C4A expression scores to symptom dimensions in a total of 4,739 BD cases with deep phenotypic data. We identified a significant association between C4A expression and psychotic mood episodes in BD type 1 (BDI). No significant association was observed between C4A expression and the occurrence of non-affective psychotic episodes in BDI, the psychosis dimensions in the total BD sample, or any other subphenotype of BD. Overall, these results points to a distinct role of C4A in BD that is restricted to vulnerability for developing psychotic symptoms during mood episodes in BDI.

Risk for psychiatric and substance use disorders as a function of transitions in Sweden's public educational system: a national study

BACKGROUND

To clarify, in a national sample, associations between risk for seven psychiatric and substance use disorders and five key transitions in Sweden's public educational system.

METHODS

Swedish-born individuals (1972-1995, N = 1 997 910) were followed through 12-31-2018, at mean age 34.9. We predicted, from these educational transitions, risk for major depression (MD), obsessive-compulsive disorder (OCD), bipolar disorder (BD), schizophrenia (SZ), anorexia nervosa (AN), alcohol use disorder (AUD), and drug use disorder (DUD), assessed from Swedish national registers, by Cox regression, censoring individuals with onsets ⩽17. We also predicted risk from the deviation of grades from family-genetic expectations (deviation 1) and from changes in grades from ages 16 to 19 (deviation 2).

RESULTS

We observed four major risk patterns across transitions in our disorders: (i) MD and BD, (ii) OCD and SZ, (iii) AUD and DUD, and (iv) AN. Failing early educational transitions had the greatest impact on risk for OCD and SZ while for other disorders, not progressing from basic to upper high school had the largest effect. Completing vocational v. college-prep upper high school was strongly associated with risk for AUD and DUD, had little relation with MD, OCD, BD, and SZ risk, and was protective for AN. Deviation 1 predicted risk most strongly for SZ, AN, and MD. Deviation 2 predicted risk most strongly for SZ, AUD, and DUD.

CONCLUSIONS

The pattern of educational transitions and within family and within person development deviations are strongly and relatively specifically associated with future risk for seven psychiatric and substance-use disorders.

The Nature of the Familial Risk for Psychosis in Bipolar Disorder

BACKGROUND AND HYPOTHESIS

To clarify whether the familial liability to psychosis associated with bipolar disorder (BD) is nonspecific or has a greater effect on risk for psychosis in cases with prominent mood symptoms and/or a remitting course.

STUDY DESIGN

We examined, in 984 809 offspring raised in intact families in Sweden, born 1980-1996 and followed-up through 2018, by multivariable Cox proportional hazards regression, risk in offspring of parents with BD for 7 psychotic disorders: Psychotic MD (PMD), psychotic BD (PBD), schizoaffective disorder (SAD), acute psychoses, psychosis NOS, delusional disorder (DD) and schizophrenia (SZ). Diagnoses were obtained from national registers.

STUDY RESULTS

In the offspring of BD parents, the hazard ratios (HR) for these 7 disorders formed an inverted U-shaped curve, rising from 2.98 for PMD, to peak at 4.49 for PBD and 5.25 for SAD, and then declining to a HR of 3.48 for acute psychoses and 3.22 for psychosis NOS, to a low of 2.19 for DD and 2.33 for SZ. A similar pattern of risks was seen in offspring of mothers and fathers affected with BD and in offspring predicted from age at onset in their BD parent.

CONCLUSIONS

The BD-associated risk for psychosis impacts most strongly on mood disorders, moderately on episodic psychotic syndromes, and least on chronic psychotic disorders. These results support prior clinical studies suggesting a qualitative difference in the familial substrate for psychosis occurring in BD and SZ.

Predictors of diagnostic conversion from major depression to bipolar disorder: a Swedish national longitudinal study

BACKGROUND

It is clinically important to predict the conversion of major depression (MD) to bipolar disorder (BD). Therefore, we sought to identify related conversion rates and risk factors.

METHODS

This cohort study included the Swedish population born from 1941 onward. Data were collected from Swedish population-based registers. Potential risk factors, including family genetic risk scores (FGRS), which were calculated based on the phenotypes of relatives in the extended family and not molecular data, and demographic/clinical characteristics from these registers were retrieved. Those with first MD registrations from 2006 were followed up until 2018. The conversion rate to BD and related risk factors were analyzed using Cox proportional hazards models. Additional analyses were performed for late converters and with stratification by sex.

RESULTS

The cumulative incidence of conversion was 5.84% [95% confidence interval (95% CI) 5.72-5.96] for 13 years. In the multivariable analysis, the strongest risk factors for conversion were high FGRS of BD [hazard ratio (HR) = 2.73, 95% CI 2.43-3.08], inpatient treatment settings (HR = 2.64, 95% CI 2.44-2.84), and psychotic depression (HR = 2.58, 95% CI 2.14-3.11). For late converters, the first registration of MD during the teenage years was a stronger risk factor when compared with the baseline model. When the interactions between risk factors and sex were significant, stratification by sex revealed that they were more predictive in females.

CONCLUSIONS

Family history of BD, inpatient treatment, and psychotic symptoms were the strongest predictors of conversion from MD to BD.

Selecting cases of major psychiatric and substance use disorders in Swedish national registries on the basis of clinical features to maximize the strength or specificity of the genetic risk

We investigate how selection of psychiatric cases by phenotypic criteria can alter the strength and specificity of their genetic risk by examining samples from national Swedish registries for five disorders: major depression (MD, N = 158,557), drug use disorder (DUD, N = 69,841), bipolar disorder (BD, N = 13,530)) ADHD (N = 54,996) and schizophrenia (N = 11,227)). We maximized the family genetic risk score (FGRS) for each disorder and then the specificity of the FGRS in six disorder pairs by univariable and multivariable regression. We use split-half methods to divide our cases for each disorder into deciles for prediction of genetic risk magnitude and quintiles for prediction of specificity by FGRS differences between two disorders. We utilized seven predictor groups: demography/sex, # registrations, site of diagnosis, severity, comorbidity, treatment, and educational/social variables. The ratio of the FGRS in the upper vs two lower deciles from our multivariable prediction model was, in order, DUD - 12.6, MD - 4.9, BD - 4.5, ADHD - 3.3 and schizophrenia 1.4. From the lowest to highest quintile, our measures of genetic specificity increased more than five-fold for i) MD vs. Anxiety Disorders, ii) MD vs BD, iii) MD versus alcohol use disorder (AUD), iv) BD vs schizophrenia and v) DUD vs AUD. This increase was nearly two-fold for ADHD vs DUD. We conclude that the level of genetic liability for our psychiatric disorders could be substantially enriched by selection of cases with our predictors. Specificity of genetic risk could also be substantially impacted by these same predictors.

Maternal early pregnancy body mass index and bipolar disorder in the offspring

OBJECTIVES

To investigate the association between maternal early pregnancy body mass index (BMI) and offspring bipolar disorder (BPD).

METHODS

We conducted a nationwide cohort study among 1,507,056 non-malformed singleton live-births in Sweden born 1983-2004. Using national registries with prospectively recorded information, we followed participants for a BPD diagnosis from ages 13 to up to 35 years. We compared BPD risks by early pregnancy BMI using hazard ratios (HR) with 95% confidence intervals (CI) from adjusted Cox models. We also conducted sibling-controlled analyses among 874,047 full siblings.

RESULTS

There were 9970 BPD diagnoses. Risk of BPD was 0.72% through 25 years of age. Maternal early pregnancy BMI was positively associated with offspring BPD risk. Compared with normal BMI (18.5-24.9), adjusted HR (95% CI) for overweight (BMI 25-29.9), obesity grade 1 (BMI 30-34.9), and obesity grades 2-3 (BMI ≥35) were 1.08 (1.02, 1.15), 1.26 (1.14, 1.40), and 1.31 (1.07, 1.60), respectively. Adjusted HR per unit BMI was 1.015 (95% CI 1.009, 1.021). A similar trend was observed among siblings. Pregnancy and neonatal complications did not substantially mediate the association between maternal obesity (BMI ≥30) and offspring BPD.

CONCLUSIONS

Maternal BMI ≥25 is associated with offspring BPD risk in a dose-response manner.

One versus two biological parents with mental disorders: Relationship to educational attainment in the next generation

BACKGROUND

Both maternal and, separately, paternal mental illness are associated with diminished academic attainment among children. However, the differential impacts of diagnostic type and degree of parental burden (e.g. one v. both parents affected) on these functional outcomes are unknown.

METHODS

Using the Swedish national patient (NPR) and multi-generation (MGR) registers, 2 226 451 children (1 290 157 parental pairs), born 1 January 1973-31 December 1997, were followed through 31 December 2013. Diagnostic status of all cohort members was defined for eleven psychiatric disorders, and families classed by exposure: (1) parents affected with any disorder, (2) parents affected with a disorder group (e.g. neuropsychiatric disorders), and (3) parents affected with a specific disorder (e.g. ADHD). Pairs were further defined as 'unaffected,' 'single-affected,', or 'dual-affected.' Among offspring, the study evaluated fulfillment of four academic milestones, from compulsory (primary) school through University (college). Sensitivity analyses considered the impact of child's own mental health, as well as parental education, on main effects.

RESULTS

Marked reductions in the odds of achievement were observed, emerging at the earliest levels of schooling for both single-affected [adjusted odds ratio (aOR), 0.50; 95% CI 0.49-0.51] and dual-affected (aOR 0.29, 95% CI 0.28-0.30) pairs and persisting thereafter [aOR range (single), 0.52-0.65; aOR range (dual), 0.30-0.40]. This pattern was repeated for analyses within diagnosis/diagnostic group. Main results were robust to adjustment for offspring mental health and parent education level.

CONCLUSIONS

Parental mental illness is associated with profound reductions in educational attainment in the subsequent generation, with children from dual-affected families at uniquely high risk.

Migration and risk of schizophrenia and bipolar disorder: A Swedish national study

OBJECTIVE

Prior studies report increased risk of schizophrenia (SCZ) in migrants relative to the native-born population; however, few have investigated bipolar disorder (BD) and migrant characteristics which may influence risk. We aimed to examine the risk of SCZ and BD in migrants and their children relative to those of Swedish ancestry, and whether risk varied by age at migration, region of origin, sex, and parental migrant status.

METHODS

We conducted a nested case-control study using 5539 SCZ cases and 20,577 BD cases diagnosed 1988-2013, individually matched to five population-based controls by birth year and sex. Conditional logistic regression was used to evaluate the risk of SCZ and BD by migrant status, region of origin and age at migration, with models stratified by sex.

RESULTS

First-generation migrants had increased risk of SCZ and decreased risk of BD. There was a distinct pattern of risk for SCZ by age at migration. Childhood migrants from all regions had increased risk of SCZ, particularly those from Africa. In contrast, risk for BD declined with age at migration, with increased risk only in Nordic child migrants. SCZ and BD diagnoses were decreased in adult migrants, elevated in second-generation migrants (with risk differing by number of migrant parents and greater for those with migrant fathers) and higher in male migrants (vs. female).

CONCLUSIONS

Age at migration, sex, and region of origin affect risk of SCZ and BD. Further research is required to determine how migration-related factors influence disease etiology and the receipt of these diagnoses.

Association between neighborhood deprivation and mortality in patients with schizophrenia and bipolar disorder-A nationwide follow-up study

OBJECTIVES

The aim was to explore the association between neighborhood deprivation and all-cause mortality and cause-specific mortalities in patients with schizophrenia and bipolar disorder. A better understanding of this potential relationship may help to identify patients with schizophrenia and bipolar disorder with an increased mortality risk.

METHODS

This nationwide study included practically all adults (≥30 years) diagnosed with schizophrenia (n = 34,544) and bipolar disorder (n = 64,035) in Sweden (1997-2017). The association between neighborhood deprivation and mortality was explored using Cox regression. All models were conducted in both men and women and adjusted for individual-level sociodemographic factors and comorbidities.

RESULTS

There was an association between level of neighborhood deprivation and all-cause mortality in both groups. The adjusted hazard ratios for all-cause mortality associated with high compared to low neighborhood deprivation were 1.18 (95% confidence interval 1.11-1.25) in patients with schizophrenia and 1.33 (1.26-1.41) in patients with bipolar disorder. The two most common mortality causes in both groups were coronary heart disease and cancer. The mortality due to coronary heart disease increased when neighborhood deprivation increased and reached 1.37 (1.18-1.60) in patients with schizophrenia and 1.70 (1.44-2.01) in patients with bipolar disorder living in the most deprived neighborhoods.

CONCLUSIONS

This study shows that neighborhood deprivation is an important risk factor for all-cause mortality and most cause-specific mortalities among patients with schizophrenia and bipolar disorder. These findings could serve as aid to policymakers when allocating healthcare resources and to clinicians who encounter patients with these conditions in deprived neighborhoods.

Psychiatric disorders and subsequent risk of cardiovascular disease: a longitudinal matched cohort study across three countries

Background

Several psychiatric disorders have been associated with increased risk of cardiovascular disease (CVD), however, the role of familial factors and the main disease trajectories remain unknown.

Methods

In this longitudinal cohort study, we identified a cohort of 900,240 patients newly diagnosed with psychiatric disorders during January 1, 1987 and December 31, 2016, their 1,002,888 unaffected full siblings, and 1:10 age- and sex-matched reference population from nationwide medical records in Sweden, who had no prior diagnosis of CVD at enrolment. We used flexible parametric models to determine the time-varying association between first-onset psychiatric disorders and incident CVD and CVD death, comparing rates of CVD among patients with psychiatric disorders to the rates of unaffected siblings and matched reference population. We also used disease trajectory analysis to identify main disease trajectories linking psychiatric disorders to CVD. Identified associations and disease trajectories of the Swedish cohort were validated in a similar cohort from nationwide medical records in Denmark (N = 875,634 patients, same criteria during January 1, 1969 and December 31, 2016) and in Estonian cohorts from the Estonian Biobank (N = 30,656 patients, same criteria during January 1, 2006 and December 31, 2020), respectively.

Findings

During up to 30 years of follow-up of the Swedish cohort, the crude incidence rate of CVD was 9.7, 7.4 and 7.0 per 1000 person-years among patients with psychiatric disorders, their unaffected siblings, and the matched reference population. Compared with their siblings, patients with psychiatric disorders experienced higher rates of CVD during the first year after diagnosis (hazard ratio [HR], 1.88; 95% confidence interval [CI], 1.79-1.98) and thereafter (1.37; 95% CI, 1.34-1.39). Similar rate increases were noted when comparing with the matched reference population. These results were replicated in the Danish cohort. We identified several disease trajectories linking psychiatric disorders to CVD in the Swedish cohort, with or without mediating medical conditions, including a direct link between psychiatric disorders and hypertensive disorder, ischemic heart disease, venous thromboembolism, angina pectoris, and stroke. These trajectories were validated in the Estonian Biobank cohort.

Interpretation

Independent of familial factors, patients with psychiatric disorders are at an elevated risk of subsequent CVD, particularly during first year after diagnosis. Increased surveillance and treatment of CVDs and CVD risk factors should be considered as an integral part of clinical management, in order to reduce risk of CVD among patients with psychiatric disorders.

Funding

This research was supported by EU Horizon 2020 Research and Innovation Action Grant, European Research Council Consolidator grant, Icelandic Research fund, Swedish Research Council, US NIMH, the Outstanding Clinical Discipline Project of Shanghai Pudong, the Fundamental Research Funds for the Central Universities, and the European Union through the European Regional Development Fund; the Research Council of Norway; the South-East Regional Health Authority, the Stiftelsen Kristian Gerhard Jebsen, and the EEA-RO-NO-2018-0535.

Is an elevated family-genetic risk for major psychiatric disorders specific to creative occupations?

BACKGROUND

Despite a large descriptive literature linking creativity and risk for psychiatric illness, the magnitude and specificity of this relationship remain controversial.

METHODS

We examined, in 1 137 354 native Swedes with one of 59 3-digit official and objective occupational codes in managerial and educated classes, their familial genetic risk score (FGRS) for ten major disorders, calculated from 1st through 5th degree relatives. Mean FGRS across disorders were calculated, in 3- and 4-digit occupational groups, and then controlled for those whose disorder onset preceded occupational choice. Using sequential analyses, p values were evaluated using Bonferroni correction.

RESULTS

3-digit professions considered to reflect creativity (e.g. 'artists' and 'authors') were among those with statistically significant elevations of FGRS. Among more specific 4-digit codes, visual artists, actors, and authors stood out with elevated genetic risks, highest for major depression (MD), anxiety disorders (AD) and OCD, more modest for bipolar disorders (BD) and schizophrenia and, for authors, for drug and alcohol use disorders. However, equal or greater elevations in FGRS across disorders were seen for religious (e.g. ministers), helping (e.g. psychologists, social workers), and teaching/academic occupations (e.g. professors). The potential pathway from FGRS → Disorder → Occupation accounts for a modest proportion of the signal, largely for MD and AD risk.

CONCLUSIONS

While traditional creative occupations were associated with elevated genetic risk for a range of psychiatric disorders, this association was not unique, as similar, or greater elevations were seen for religious, helping and teaching professions and was stronger for internalizing than psychotic disorders.

Associations of pregnancy complications and neonatal characteristics with bipolar disorder in the offspring: Nationwide cohort and sibling-controlled studies

OBJECTIVES

To investigate associations of neonatal characteristics and pregnancy complications with bipolar disorder (BPD) in offspring.

METHODS

We conducted a nationwide cohort study among 2,059,578 non-malformed singleton live-births in Sweden born 1983-2004. Using national registries with prospectively recorded information, we followed participants for a BPD diagnosis from 13 up to 34 years of age. We compared BPD risks between exposure categories using hazard ratios (HR) with 95% confidence intervals (CI) from adjusted Cox models. We also conducted sibling-controlled analyses among 1,467,819 full siblings.

RESULTS

There were 14,998 BPD diagnoses. Risk of BPD was 0.74% through 25 years of age. Very/extremely preterm birth (22 to 31 weeks) was related to increased BPD HRs in sibling-controlled analyses; compared with a gestational age of 37 weeks, adjusted HR (95% CI) for 31, 28, and 22 weeks were, respectively, 1.31 (0.99, 1.74), 2.09 (1.15, 3.79), and 5.74 (1.15, 28.63). Spontaneous but not medically indicated very/extremely preterm birth was associated with increased risk. Compared with vaginal birth, caesarean section birth was associated with 1.20 (1.08, 1.33) and 1.58 (1.06, 2.36) times higher BPD risk in general and sibling cohorts, respectively. Small-for-gestational age (SGA) birth was related to increased BPD HRs in general cohort and sibling analyses (HRs [95% CI] were 1.22 [1.06, 1.39] and 1.68 [1.13, 2.50], respectively); only term SGA was associated with increased risk. Head circumference-for-gestational age, gestational diabetes, preeclampsia, and placental abruption were not associated with BPD.

CONCLUSIONS

Very/extremely preterm birth, caesarean birth, and SGA are related to BPD incidence.

Differences in genetic risk score profiles for drug use disorder, major depression, and ADHD as a function of sex, age at onset, recurrence, mode of ascertainment, and treatment

BACKGROUND

Do genetic risk profiles for drug use disorder (DUD), major depression (MD), and attention-deficit hyperactivity disorder (ADHD) differ substantially as a function of sex, age at onset (AAO), recurrence, mode of ascertainment, and treatment?

METHODS

Family genetic risk scores (FGRS) for MD, anxiety disorders, bipolar disorder, schizophrenia, alcohol use disorder, DUD, ADHD, and autism-spectrum disorder were calculated from 1st-5th degree relatives in the Swedish population born 1932-1995 (n = 5 829 952). Profiles of these FGRS were obtained and compared across various subgroups of DUD, MD, and ADHD cases.

RESULTS

Differences in FGRS profiles for DUD, MD, and ADHD by sex were modest, but they varied substantially by AAO, recurrence, ascertainment, and treatment with scores typically higher in cases with greater severity (e.g. early AAO, high recurrence, ascertainment in high intensity clinical settings, and treatment). However, severity was not always related to purer genetic profiles, as genetic risk for many disorders often increased together. However, some results, such as by mode of ascertainment from different Swedish registries, produced qualitative differences in FGRS profiles.

CONCLUSIONS

Differences in FGRS profiles for DUD, MD, and ADHD varied substantially by AAO, recurrence, ascertainment, and treatment. Replication of psychiatric studies, particularly those examining genetic factors, may be difficult unless cases are matched not only by diagnosis but by important clinical characteristics. Genetic correlations between psychiatric disorders could arise through one disorder impacting on the patterns of ascertainment for the other, rather than from the direct effects of shared genetic liabilities.

The financial situation before and after first-time psychiatric in-patient diagnosis of schizophrenia spectrum, bipolar, and major depressive disorder

Schizophrenia spectrum, bipolar, and major depressive disorders are severe mental illnesses (SMIs) that not only entail great suffering for those affected but also major societal costs. In this study, I use administrative register data to provide a detailed picture of the financial situation of people with SMI in Sweden during a period of ±10 years around first-time psychiatric in-patient diagnosis of schizophrenia spectrum, bipolar, and major depressive disorders. Receiving a diagnosis was associated with a considerable drop in earnings, which was largely compensated for by social transfers: mainly sickness and disability insurance. However, there were also large and increasing pre-diagnosis earnings gaps, relative to matched comparison groups, especially among those with schizophrenia spectrum disorders. These gaps were to a lesser extent compensated for by social transfers. Consequently, there were permanent and increasing - due to lost earnings growth - income differentials. Hence, findings in previous studies are confirmed: even in an advanced welfare state, people with SMI - especially those with schizophrenia - have an extremely weak position on the labour market and an equally difficult financial situation.

The impact of sex, age at onset, recurrence, mode of ascertainment and medical complications on the family genetic risk score profiles for alcohol use disorder

BACKGROUND

Alcohol use disorder (AUD) is clinically heterogeneous. We examine its potential genetic heterogeneity as a function of sex, age, clinical features and mode of ascertainment.

METHODS

In the Swedish population born 1932-1995 (n = 5 829 952), we examined the genetic risk profiles for AUD, major depression (MD), anxiety disorders, bipolar disorder, drug use disorder (DUD), attention deficit-hyperactivity disorder (ADHD) and criminal behavior (CB) in 361 124 cases of AUD subdivided by sex, age at onset (AAO), recurrence, mode of ascertainment and medical complications. Family genetic risk scores (FGRS), calculated from 1st to 5th-degree relatives controlling of cohabitation, assesses genetic risk from phenotypes in the family, not from DNA variants.

RESULTS

FGRS profiles differed modestly across sex with all scores higher in females. Differences were more pronounced for AAO and recurrence with the FGRS for AUD, DUD, ADHD and CB substantially higher in cases with early AAO or high recurrence rates. Genetic profiles differed considerably by mode of ascertainment, with higher FGRS for AUD and most other disorders in patients seen in hospital v. primary care settings. Cases of AUD with medical complications had higher FGRS for AUD. AUD cases comorbid with MD and DUD had higher FGRS risk for AUD, but this genetic may be less specific given increases in FGRS for multiple other disorders.

CONCLUSIONS

From a genetic perspective, AUD differs substantially as a function of AAO, recurrence, mode of ascertainment and patterns of comorbidity, suggesting caution in cross-sample comparisons of AUD cohorts that differ in these features.

Impact of comorbidity on family genetic risk profiles for psychiatric and substance use disorders: a descriptive analysis

BACKGROUND

- Comorbidity between psychiatric disorders is extensive but, from a genetic perspective, still poorly understood. Modern molecular genetic approaches to this problem are limited by a reliance on case-control designs.

METHODS

- In 5 828 760 individuals born in Sweden from 1932-1995 with a mean (s.d.) age at follow-up of 54.4 (18.1), we examined family genetic risk score (FGRS) profiles including internalizing, psychotic, substance use and developmental disorders in 10 pairs of psychiatric and substance use disorders diagnosed from population registries. We examined these profiles in three groups of patients: disorder A only, disorder B only and comorbid cases with both disorders.

RESULTS

- The most common pattern of findings, seen in five pairings, was simple and quantitative. Comorbid cases had higher FGRS than both non-comorbid cases for all (or nearly all) disorders. However, the pattern was more complex in the remaining five pairings and included qualitative changes where the comorbid cases showed no increases in FGRS for certain disorders and in a few cases significant decreases. Several comparisons showed an asymmetric pattern of findings with increases, in comorbidity compared to single disorder cases, of the FGRS for only one of the two disorders.

CONCLUSIONS

- The examination of FGRS profiles in general population samples where all disorders are assessed in all subjects provides a fruitful line of inquiry to understand the origins of psychiatric comorbidity. Further work will be needed, with an expansion of analytic approaches, to gain deeper insights into the complex mechanisms likely involved.

Association of premorbid intelligence with level of functioning and illness severity in bipolar disorder

BACKGROUND

Bipolar disorder is a severe psychiatric syndrome defined by periodic mood shifts. Patients with bipolar disorder show cognitive impairments relative to healthy controls. The risk of developing schizophrenia, and partially also bipolar disorder, has previously been shown to increase with lower premorbid intelligence. It is not known if premorbid intelligence is associated with level of functioning and illness severity of people having developed bipolar disorder.

METHODS

We used multiple linear and ordinal regression to analyze how premorbid intelligence, as measured at conscription, associate with functional outcome and illness severity in Swedish male bipolar disorder patients (n = 788).

RESULTS

We found that lower premorbid intelligence is associated with lower percentage of time in work, after adjusting for age and bipolar subtype, and correcting for multiple comparisons. We also found a strong negative association with the total number of inpatient episodes and psychiatric comorbidity, but not with interepisodic remission, treatment with psychotherapy or lithium or the presence of any complicating socioeconomical factors. Adjusting for confounding genetic factors using polygenic risk scores for bipolar disorder and schizophrenia had no effect on the associations.

LIMITATIONS

This study lacks females and controls and may thus have lower generalizability.

CONCLUSION

In conclusion, premorbid intelligence is associated with both level of functioning and illness severity as well as comorbidity in bipolar disorder patients. Further research is needed to develop targeted interventions for this subgroup of bipolar disorder patients.

Genetic liability to suicide attempt, suicide death, and psychiatric and substance use disorders on the risk for suicide attempt and suicide death: a Swedish national study

BACKGROUND

How does genetic liability to suicide attempt (SA), suicide death (SD), major depression (MD), bipolar disorder (BD), schizophrenia (SZ), alcohol use disorder (AUD), and drug use disorder (DUD) impact on risk for SA and SD?

METHODS

In the Swedish general population born 1932-1995 and followed through 2017 (n = 7 661 519), we calculate family genetic risk scores (FGRS) for SA, SD, MD, BD, SZ, AUD, and DUD. Registration for SA and SD was assessed from Swedish national registers.

RESULTS

In univariate and multivariate models predicting SA, FGRS were highest for SA, AUD, DUD, and MD. In univariate models predicting SD, the strongest FGRS were AUD, DUD, SA, and SD. In multivariate models, the FGRS for SA and AUD were higher in predicting SA while the FGRS for SD, BD, and SZ were higher in predicting SD. Higher FGRS for all disorders significantly predicted both younger age at first SA and frequency of attempts. For SD, higher FGRS for MD, AUD, and SD predicted later age at SD. Mediation of FGRS effects on SA and SD was more pronounced for SD than SA, strongest for AUD, DUD, and SZ FGRS and weakest for MD.

CONCLUSIONS

FGRS for both SA and SD and for our five psychiatric disorders impact on risk for SA and SD in a complex manner. While some of the impact of genetic risk factors for psychiatric disorders on risk for SA and SD is mediated through developing the disorders, these risks also predispose directly to suicidal behaviors.

Effect of CYP2C19 polymorphisms on antidepressant prescription patterns and treatment emergent mania in bipolar disorder

Antidepressant medication is used extensively to treat bipolar depression despite uncertain efficacy. The cytochrome P450 (CYP) 2C19 enzyme metabolize several antidepressants, and polymorphisms in the corresponding gene CYP2C19 influence plasma concentration and hence treatment outcomes in major depressive disorder. Here, we investigate if CYP2C19 polymorphisms are associated with antidepressant treatment patterns and the risk of mania when antidepressants are used in bipolar disorder. Two single nucleotide polymorphisms (rs4244285 and rs12248560) were used to classify 5019 bipolar disorder patients into CYP2C19 metabolic phenotypes ranging from poor to ultra-rapid metabolizers. We used Swedish national registry data 2005-2017 on dispensed medications and inpatient care to estimate risks for early-treatment persistence, treatment discontinuation, switching to a new antidepressant medication, and mania within 3 months of treatment initiation in patients treated with citalopram, escitalopram, sertraline, amitriptyline, and clomipramine. Metabolic phenotypes of CYP2C19 were not robustly associated with the investigated treatment outcomes based on dispense patterns. Slower metabolism was associated with an increased risk of treatment emergent mania for sertraline (hazard ratio [HR] = 1.3, 95% CI = 1.04-1.62, p = 0.02) and the tricyclic antidepressants amitriptyline and clomipramine (HR = 1.46, 95% CI = 1.05-2.02, p = 0.024). In a large study of the impact of CYP2C19 metabolic phenotypes on antidepressant treatment of bipolar depression, we found an association between slower CYP2C19 metabolism and higher risk of treatment emergent mania, which is a step towards personalized risk assessments. There were, however, no clear associations with early treatment persistence, treatment discontinuation, and switching to a new antidepressant.

Use of hormonal contraceptives and antidepressants and risks of suicidal behavior and accidents among women with premenstrual disorders: a nationwide cohort study

BACKGROUND

Women with premenstrual disorders (PMDs) are at increased risks of suicidal behavior and accidents. However, the effect of PMD first-line treatment on such risks have not been assessed.

METHODS

To study the association between use of hormonal contraceptives or antidepressants and subsequent risks of suicidal behavior and accidents among women with PMDs. We conducted a nationwide register-based cohort study with between- and within-individual analyses in Sweden. All women with a clinical diagnosis/indication of PMDs recorded in the Patient Register and the Prescribed Drug Register during 1987-2011 were included (n = 23 029, age 15-52 years). Information on hormonal contraceptives and antidepressants prescribed for these women was obtained from the Prescribed Drug Register. Events of suicidal behavior (complete suicide and suicide attempt) and accidents were separately identified through the Patient and the Causes of Death Registers. Incidence rate ratios (IRRs) and 95% confidence intervals (CIs) of suicidal behavior and accidents after use of hormonal contraceptives or antidepressants were estimated in between-individual and within-individual analyses (i.e., comparing the risk between use and no use in the same individual) using Poisson regression.

RESULTS

Women with PMDs were followed for a median of 6.2 years. Compared to no use of hormonal contraceptives, use of hormonal contraceptives was associated with a lower risk of suicidal behavior in both between-individual (IRR 0.76, 0.43-1.34) and within-individual analyses (IRR 0.65, 0.51-0.83). These risk reductions were primarily restricted to combined products (IRR 0.18, 0.07-0.47 and 0.19, 0.08-0.42 in between- and within-individual analyses) and observed among women with/without psychiatric comorbidities (p for interaction 0.830 and 0.043 in between- and within-individual analyses). Yet, the use of hormonal contraceptives was not consistently associated with risk of accidents between between-individual (IRR 1.13, 1.01-1.27) and within-individual analyses (IRR 1.01, 0.92-1.11). Use of antidepressants was associated with a higher risk of suicidal behavior and accidents in both between- and within-individual analyses.

CONCLUSIONS

Our findings suggest that use of hormonal contraceptives, particularly combined products, is associated with reduced rates of suicidal behaviors, but not accidents, among women with PMDs. The estimates for antidepressants may be biased by indication.

The Role of Mental Health and Behavioral Disorders in the Development of Temporomandibular Disorder: A SWEREG-TMD Nationwide Case-Control Study

Purpose

There is a well-known association between mental and behavioral disorders (MBD) and temporomandibular disorder (TMD), although the association has not been established in population-based samples. This study aimed to investigate this relationship using national population-based registry data.

Patients and Methods

This case-control study used prospectively collected data from Swedish national registries to investigate exposure to MBD and the probability of developing TMD in all Swedish citizens with hospital-diagnosed or surgically treated TMD between 1998 and 2016. Odds ratios were calculated using conditional logistic regression adjusted for educational level, living area, country of birth, musculoskeletal comorbidity, and history of orofacial/neck trauma.

Results

A statistically significant association between MBD and TMD was found for mood affective disorders (OR 1.4), neurotic, stress-related and somatoform disorders (OR 1.7), behavioral syndromes associated with psychological disturbances and physical factors (OR 1.4), disorders of adult personality and behavior (OR 1.4), disorders of psychological development (OR 1.3), behavioral and emotional disorders with onset usually occurring in childhood and adolescence (OR 1.4), and unspecified mental disorder (OR 1.3). The association was stronger for TMD requiring surgery, with the strongest association in patients with disorders of psychological development (OR 2.9). No significant association was found with schizophrenia, schizotypal and delusional disorders, or mental retardation.

Conclusion

The findings indicate an increased probability of TMD among patients with a history of certain MBD diagnoses, and a stronger association with TMD requiring surgery, specifically repeated surgery. This highlights the need for improved preoperative understanding of the impact of MBD on TMD, as TMD and chronic pain itself may have a negative impact on mental health.

Association between parental mental illness and autoimmune diseases in the offspring - A nationwide register-based cohort study in Sweden

Mental illness has been previously linked with autoimmune diseases, yet the associations between parental mental illness and offspring's risk of autoimmune diseases is largely unknown. We conducted a population-based cohort study of 2,192,490 Swedish children born between 1991 and 2011 and their parents to determine the associations between parental mental illness and risk of autoimmune diseases among the offspring. Time-dependent diagnoses of parental mental illness (psychosis, alcohol/drug misuse, depression, anxiety, eating disorders, personality disorders, attention deficit hyperactivity disorder, autism spectrum disorder) and offspring autoimmune diseases (type 1 diabetes (T1D), juvenile idiopathic arthritis (JIA), systemic lupus erythematosus, psoriasis, multiple sclerosis, inflammatory bowel disease (IBD), coeliac disease) were identified from inpatient/outpatient healthcare visits. Associations were measured by hazard ratios (HRs) adjusted for potential confounders. Overall, parental mental illness was associated with a small increase in risk of offspring's autoimmune diseases (HR 1.05, 95% CI 1.02-1.08). However, parental common mental disorder (anxiety/depression) was associated with higher risk of JIA, psoriasis, and T1D (HR T1D 1.11, 95% CI 1.01-1.22), while maternal psychosis with reduced risk of coeliac disease (HR 0.68, 95% CI 0.49-0.95) and paternal alcohol/drug misuse with reduced risk of IBD (HR 0.80, 95% CI 0.64-0.99). Maternal eating disorders were associated with a markedly increased risk for T1D (HR 1.41, 95% CI 1.05-1.89). Further studies are needed to confirm these findings and to understand underlying mechanisms. There is a need for greater clinical awareness about potential risk of JIA, psoriasis, and T1D among children of parents with common psychiatric morbidity.

Validity of eating disorder diagnoses in the Swedish national patient register

The Swedish National Patient Register (NPR) includes population-level longitudinal data, and determining the validity of NPR diagnoses is critical to undergirding the research and policy recommendations they inform. Sweden also has the integrated "Riksät" and "Stepwise" National Quality Registers (QR), with data from specialized eating disorder (ED) treatment based on structured, valid assessment methods. To validate NPR ED diagnoses, we compared ICD-10-based anorexia nervosa (AN), bulimia nervosa (BN), and unspecified ED in NPR to DSM-IV-based AN, BN, and ED not otherwise specified category (EDNOS) in QR. Patients' first diagnoses registered in QR between February 2008 and August 2013 were compared with NPR diagnoses entered within ±1 month (N = 2074). QR registration includes the semi-structured DSM-IV-based Structured ED Interview. Each ED diagnosis was analyzed separately for degree of match using several indices: overall agreement, sensitivity, positive predictive value, specificity, negative predictive value, area under the curve, and Cohen's kappa. Results showed moderate to excellent agreement depending on estimate (e.g. positive predictive values AN: 0.747; BN:.836; EDNOS: 0.761), except for a somewhat low sensitivity for BN, and EDNOS agreement was overall the lowest. Case prevalence in the NPR and QR was highly similar for AN, and within five percentage points for BN and EDNOS. Generalizability is hampered by limited age range and diagnostic resolution as well as few males. Available data precluded study of presence/absence of ED, and complementary approaches are considered for future research. We conclude that NPR ED diagnoses have acceptable validity and are appropriate for use in research.

Associations between prisons and recidivism: A nationwide longitudinal study

Objectives

To examine differences in recidivism rates between different prisons using two designs—between-individual and within-individual—to account for confounding factors.

Methods

We examined recidivism rates among 37,891 individuals released from 44 Swedish prisons in three security levels, and who were followed from 2006 to 2013. We used longitudinal data from nationwide registers, including all convictions from district courts. First, we applied a between-individual design (Cox proportional hazards regression), comparing reconviction rates between individuals released from prisons within the same security level, while adjusting for a range of individual-level covariates. Second, we applied a within-individual design (stratified Cox proportional hazards regression), comparing rates of reconviction within the same individuals, i.e., we compared rates after release from one prison to the rates in the same individual after release from another prison, thus adjusting for all time-invariant confounders within each individual (e.g. genetics and early environment). We also adjusted for a range of time-varying individual-level covariates.

Results

Results showed differences in the hazard of recidivism between different prisons in between-individual analyses, with hazards ranging from 1.22 (1.05–1.43) to 4.99 (2.44–10.21). Results from within-individual analyses, which further adjusted for all time-invariant confounders, showed minimal differences between prisons, with hazards ranging from 0.95 (0.87–1.05) to 1.05 (0.95–1.16). Only small differences were found when violent and non-violent crimes were analyzed separately.

Conclusions

The study highlights the importance of research designs that more fully adjust for individual-level confounding factors to avoid over-interpretation of the variability in comparisons across prisons.

Proton pump inhibitor use and risk of depression and anxiety in children: nationwide cohort study

Although some data have linked proton pump inhibitor (PPI) use to risk of depression and anxiety, there are no studies investigating this safety issue in children. This study investigated the association between PPI use and risk of depression and anxiety in children. We conducted a nationwide register‐based cohort study in Sweden, July 1, 2007, to December 31, 2016. Following matching on age and propensity score, we included 29,320 pairs of PPI initiators and noninitiators among children aged 7–17 years old. The primary analysis examined the risk of incident depression and anxiety, a composite outcome defined as a diagnosis of depression, anxiety, or a prescription for an antidepressant. Children who initiated PPI use had higher hazards for risk of depression and anxiety compared with noninitiators (hazard ratios [HRs], 2.61; 95% confidence interval [CI], 2.32–2.94). In analyses of the timing of depression and anxiety onset after PPI initiation, the HRs were 3.71 (95% CI, 2.17–6.34) for 1–30 days, 3.47 (95% CI, 2.33–5.18) for 31–90 days, 2.71 (2.04–3.60) for 91–180 days, 2.52 (2.00–3.16) for 181–365 days, and 2.34 (1.94–2.82) for 366–730 days. Significant associations were observed across all age groups. The magnitude of the association increased with longer duration of PPI use (p for trend < 0.0001). The association was consistent through all sensitivity analyses, including high‐dimensional propensity score matching (HR, 2.31, 95% CI, 2.05–2.61). PPI use was associated with increased risk of depression and anxiety in children. Further investigation is warranted to confirm or refute this potential association.

Proteins associated with future suicide attempts in bipolar disorder: A large-scale biomarker discovery study

Suicide is a major cause of death worldwide. Several biological systems have been implicated in suicidal behavior but studies of candidate biomarkers have failed to produce clinically relevant biomarkers for suicide prediction. The objective of the present study was to identify novel candidate biomarkers for suicidal behavior. We used a nested case-control study design where a large cohort of patients with bipolar disorder (N = 5 110) were followed up to 8 years after blood sampling. We included patients that attempted suicide during follow-up (N = 348) and matched bipolar disorder patients from the same cohort who did not attempt suicide during the study period (N = 348) and analyzed a total of 92 proteins with a neuro exploratory multiplex panel. Using a multivariate classification algorithm devised to minimize bias in variable selection, we identified a parsimonious set of proteins that best discriminated bipolar disorder patients with and without prospective suicide attempts. The algorithm selected 16 proteins for the minimal-optimal classification model, which outperformed 500 models with permuted outcome (p = 0.0004) but had low sensitivity (53%) and specificity (64%). The candidate proteins were then entered in separate logistic regression models to calculate protein-specific associations with prospective suicide attempts. In individual analyses, three of these proteins were significantly associated with prospective suicide attempt (SCGB1A1, ANXA10, and CETN2). Most of the candidate proteins are novel to suicide research.

Association of severe childhood infections with depression and intentional self-harm in adolescents and young adults

Early-life infections have been linked with subsequent depression and self-harm. Examination of specific groups of infections and the role of familial factors may elucidate this observed relationship. We addressed these considerations in our investigations of the association of severe childhood infections with the risks of depression and self-harm in adolescence and early-adulthood. This population-based cohort study included all individuals born in Sweden between 1982 and 1996, with follow-up through 2013 (N = 1,506,070). Severe childhood infections were identified using inpatient and outpatient diagnoses from birth through age 12. Any infection as well as specific groups of infections were investigated. We examined diagnoses of depression and self-harm within inpatient and outpatient care and death by self-harm between ages 13 and 31. Cox proportional hazards regression models were used to estimate absolute risks, hazard ratios (HRs), and 95% CIs. When adjusting for sex and birth year, individuals exposed to any childhood infection demonstrated increased absolute risk differences for both outcomes (2.42% [95% CI, 0.41-4.43%] of being diagnosed with depression up until age 31, and 0.73% [-2.05% to 3.51%] of self-harm up until age 31) and increased relative risks (HR, 1.22 [1.20-1.24] for depression and HR, 1.29 [1.25-1.32] for self-harm). When controlling for unmeasured factors shared between family members by comparing discordant siblings, no strong association persisted. Our findings show that childhood infections may not be involved in the etiology of later depression and self-harm, and highlight the importance of identifying these genetic and environmental familial risk factors, which may serve as targets for interventions.

Validity and reliability of the diagnostic codes for hypochondriasis and dysmorphophobia in the Swedish National Patient Register: a retrospective chart review

OBJECTIVES

In the International Classification of Diseases, Tenth Edition (ICD-10), hypochondriasis (illness anxiety disorder) and dysmorphophobia (body dysmorphic disorder) share the same diagnostic code (F45.2). However, the Swedish ICD-10 allows for these disorders to be coded separately (F45.2 and F45.2A, respectively), potentially offering unique opportunities for register-based research on these conditions. We assessed the validity and reliability of their ICD-10 codes in the Swedish National Patient Register (NPR).

DESIGN

Retrospective chart review.

METHODS

Six hundred individuals with a diagnosis of hypochondriasis or dysmorphophobia (300 each) were randomly selected from the NPR. Their medical files were requested from the corresponding clinics, located anywhere in Sweden. Two independent raters assessed each file according to ICD-10 definitions and Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision and Fifth Edition criteria. Raters also completed the Clinical Global Impression-Severity (CGI-S) and the Global Assessment of Functioning (GAF).

PRIMARY OUTCOME MEASURE

Per cent between-rater agreement and positive predictive value (PPV). Intraclass correlation coefficients for the CGI-S and the GAF.

RESULTS

Eighty-four hypochondriasis and 122 dysmorphophobia files were received and analysed. The inter-rater agreement rate regarding the presence or absence of a diagnosis was 95.2% for hypochondriasis and 92.6% for dysmorphophobia. Sixty-seven hypochondriasis files (79.8%) and 111 dysmorphophobia files (91.0%) were considered 'true positive' cases (PPV=0.80 and PPV=0.91, respectively). CGI-S scores indicated that symptoms were moderately to markedly severe, while GAF scores suggested moderate impairment for hypochondriasis cases and moderate to serious impairment for dysmorphophobia cases. CGI-S and GAF inter-rater agreement were good for hypochondriasis and moderate for dysmorphophobia.

CONCLUSIONS

The Swedish ICD-10 codes for hypochondriasis and dysmorphophobia are sufficiently valid and reliable for register-based studies. The results of such studies should be interpreted in the context of a possible over-representation of severe and highly impaired cases in the register, particularly for dysmorphophobia.

Use of register- and survey-based measures of anxiety in a population-based Danish cohort

OBJECTIVE

We explored the comparability of anxiety measures from register- and survey-based data including analyses of prevalence and associations with selected psychiatric and somatic diseases.

METHODS

We measured anxiety using Danish registers (hospital diagnosis and anxiolytic drug prescriptions), self-reports, symptom checklist (SCL) scores, and a clinical interview in 7493 adults with mean age 52 (SD 13.3) years who participated in a health survey between 2012 and 2015. We estimated the prevalence of anxiety, agreement between different measures and performed quantitative bias analysis.

RESULTS

The lifetime prevalence of hospital diagnosed anxiety, anxiolytic drug prescriptions, and self-reported anxiety were 4.4%, 6.2%, and 5.1%, respectively, after adjusting for selective participation. The agreement between the different anxiety measures was low. Thus, 25% with an anxiety diagnosis and 20% with anxiolytic drug prescriptions also had a high SCL score. Anxiolytic drugs were the only measure significantly associated with higher odds of heart disease. Hospital diagnosis and self-reported anxiety were associated with depression with odds ratio (OR) above 15, whereas anxiolytic drug prescriptions were less strongly associated (OR = 2.2(95% confidence interval: 1.26-3.91)). The risk estimates attenuated considerably when correcting for measurement error, whereas the ORs became slightly higher when the selective participation in the survey was accounted for.

CONCLUSION

Anxiety diagnosed in hospitals and self-reported anxiety showed low level of agreement but provide comparable results regarding frequency measures and associations with disease outcomes.

Psychiatric Disorders in Patients With a Diagnosis of Celiac Disease During Childhood From 1973 to 2016

BACKGROUND & AIMS

Few studies have explored the link between childhood celiac disease and long-term psychiatric comorbidities. We performed a population-based cohort study of associations between childhood celiac disease and psychiatric disorders and investigated whether risk persists into adulthood.

METHODS

We performed a nationwide study in Sweden using data from the Epidemiology Strengthened by histoPathology Reports in Sweden cohort. In this cohort, 19,186 children with a diagnosis of biopsy-verified celiac disease from 1973 through 2016 were identified from Sweden's 28 pathology departments. Each patient was matched with as many as 5 reference children (controls, n = 94,249). Data on psychiatric disorders were obtained from the patient register. We used Cox proportional modeling to estimate hazard ratios (HRs).

RESULTS

During a median follow-up period of 12.3 years, 3174 children (16.5%) with celiac disease received a new diagnosis of a psychiatric disorder, compared with 13,286 controls (14.1%). Corresponding incidence rates were 12.2 per 1000 person-years (95% CI, 11.8-12.7) vs 10.3 per 1000 person-years (95% Cl, 10.2-10.5). Childhood celiac disease was associated with a 19% increase in risk of any psychiatric disorder (95% CI, 1.14-1.23); the increase in risk was observed in all childhood age groups. The highest HRs were seen in the first year after celiac diagnosis (HR, 1.70; 95% CI, 1.41-2.05). The risk increase persisted into adulthood (age, >18 y: HR, 1.11; 95% CI, 1.04-1.17). We found increased risks of mood disorders (HR, 1.20; 95% CI, 1.12-1.28), anxiety disorders (HR, 1.12; 95% CI, 1.06-1.19), eating disorders (HR, 1.34; 95% CI, 1.18-1.51), attention deficit hyperactivity disorder (HR, 1.29; 95% CI, 1.20-1.39), and autism spectrum disorder (HR, 1.47; 95% CI, 1.32-1.64). We found no statistically significant risk increase for psychotic disorders, psychoactive substance misuse, behavioral disorders, personality disorders, suicide attempt, or suicide. Celiac disease also was linked to an increased use of psychiatric drugs (HR, 1.34; 95% CI, 1.24-1.43). A conditional logistic regression found that psychiatric disorders also were more common before a diagnosis of celiac disease (odds ratio, 1.56; 95% CI, 1.39-1.76).

CONCLUSIONS

Childhood celiac disease is associated with an increased risk of subsequent psychiatric disorders, which persists into adulthood. Mental health surveillance should be integral in the care of celiac disease.

Family Genetic Risk Scores and the Genetic Architecture of Major Affective and Psychotic Disorders in a Swedish National Sample

Importance

Family and genetic approaches have traditionally been used to evaluate our diagnostic concepts. Using a novel method, the family genetic risk score (FGRS), can we validate the genetic architecture of major affective and psychotic disorders in a national Swedish sample?

Objective

To determine whether FGRSs, calculated for the entire Swedish population, can elucidate the genetic relationship between major affective and psychotic disorders and clarify the association of genetic risk with important clinical features of disease.

Design, Setting, and Participants

This cohort study included the native Swedish population born from January 1, 1950, through December 31, 1995, and followed up through December 31, 2017. Data were collected from Swedish population-based primary care, specialist, and hospital registers, including age at first registration for a psychiatric diagnosis and number of registrations for major depression, bipolar disorder, and schizophrenia. Data were analyzed from October 15, 2020, to February 2, 2021.

Exposures

FGRSs for major depression, bipolar disorder, and schizophrenia calculated from morbidity risks for disorders in first- through fifth-degree relatives, controlling for cohabitation.

Main Outcomes and Measures

Diagnoses of major depression, bipolar disorder, schizophrenia, schizoaffective disorder, and other nonaffective psychoses (ONAPs), age at registration, and number of registrations for major depression, bipolar disorder, and schizophrenia. Diagnostic conversion of major depression to bipolar disorder and ONAPs to schizophrenia was assessed by Cox proportional hazards regression models.

Results

The cohort included 4 129 002 individuals (51.4% male) with a mean (SD) age at follow-up of 45.5 (13.4) years. Mean FGRSs for major depression, bipolar disorder, and schizophrenia produced distinct patterns for major depression, bipolar disorder, schizophrenia, schizoaffective disorder, and ONAPs with large separations between disorders. In major depression, bipolar disorder, and schizophrenia, high FGRSs were associated with early age at onset and high rates of recurrence: a high mean FGRS for bipolar disorder was associated with early age at onset (younger than 25 years, 0.11; 95% CI, 0.11-0.12) and higher recurrence (8 or more registrations, 0.11; 95% CI, 0.11-0.12) in major depression. The schizophrenia FGRS was separately associated with psychotic and nonpsychotic forms of major depression (0.10; 95% CI, 0.06-0.14 vs 0.03; 95% CI, 0.02-0.03) and bipolar disorder (0.22; 95% CI, 0.16-0.28 vs 0.11; 95% CI, 0.09-0.12). The bipolar disorder and schizophrenia FGRSs were associated with conversion from major depression to bipolar disorder (eg, hazard ratio, 1.70 [95% CI, 1.63-1.78] for high vs low bipolar FGRS) and ONAP to schizophrenia (eg, hazard ratio, 1.38 [95% CI, 1.27-1.51] for high vs low schizophrenia FGRS).

Conclusions and Relevance

In this Swedish cohort study, the FGRSs for major depression, bipolar disorder, and schizophrenia for the Swedish population clearly separated major affective and psychotic disorders from each other in a larger and more representative patient sample than previously possible. These findings provide possible validation, from a genetic perspective, for these major diagnostic categories. These results replicated and extended prior observations on more limited samples of the association of FGRS with age at onset, recurrence, psychotic subtypes, and diagnostic conversions.

The patterns of family genetic risk scores for eleven major psychiatric and substance use disorders in a Swedish national sample

To clarify the structure of genetic risks for 11 major psychiatric disorders, we calculated, from morbidity risks for disorders in 1st-5th degree relatives controlling for cohabitation effects, in the Swedish population born between 1932 and 1995 (n = 5,830,014), the family genetic risk scores (FGRS) for major depression (MD), anxiety disorders (AD), obsessive-compulsive disorder (OCD), bipolar disorder (BD), schizophrenia (SZ), bulimia (BUL), anorexia nervosa (AN), alcohol use disorder (AUD), drug use disorder (DUD), ADHD, and autism-spectrum disorder (ASD). For all affected individuals, we calculated their mean standardized FGRS for each disorder. The patterns of FGRS were quite similar for MD and AD, and for AUD and DUD, but substantially less similar for BUL and AN, BD and SZ, and ADHD and ASD. While OCD had high levels of FGRS for MD and AD, the overall FGRS profile differed considerably from MD and AD. ADHD FGRS scores were substantially elevated in AUD and DUD. FGRS scores for BD, OCD, AN, ASD, ADHD, and especially SZ were relatively disorder-specific while genetic risk for MD and AD had more generalized effects. The levels of FGRS for BMI, coronary artery disease, and educational attainment across our disorders replicated prior associations found using molecular genetic methods. All diagnostic categories examined had elevated FGRS for many disorders producing, for each condition, an informative FGRS profile. Using a novel method which approximates, from pedigree data, aggregate genetic risk, we have replicated and extended prior insights into the structure of genetic risk factors for key psychiatric illnesses.

Clinical indications of premenstrual disorders and subsequent risk of injury: a population-based cohort study in Sweden

BACKGROUND

Premenstrual disorders, including premenstrual syndrome and premenstrual dysphoric disorder, are suggested to be correlated with suicidal behavior and accidents in cross-sectional and retrospective studies. However, prospective data are still lacking.

METHODS

We performed a population-based cohort study including 1,472,379 Swedish women of reproductive age who were followed from 2001 to 2012. Within the cohort, we also performed a sibling analysis where we compared the rates of injury between full sisters. By linking to the Patient and the Prescribed Drug Registers, we identified 18,628 women with any clinical indications for premenstrual disorders in the cohort (population analysis) and 7674 women in the sibling analysis. Any injury, primarily suicidal behavior (completed suicide and suicide attempt) or accidents (e.g., fall and transportation accidents), was identified through the Patient and Causes of Death Registers as the primary outcome. We estimated hazard ratios (HRs) and 95% confidence intervals (CIs) of these outcomes among women with premenstrual disorders in both population and sibling analyses using multivariable Cox proportional hazards regression.

RESULTS

During a maximal follow-up of 12 years (mean 9.55 years), we identified 2390 women with premenstrual disorders with any injury; 216 through suicidal behavior and 2191 through accidents. Compared to women without premenstrual disorders, women with premenstrual disorders were at increased risk of any injury (HR 1.37, 95% CI 1.31-1.42), particularly suicidal behavior (HR 2.26, 95% CI 1.97-2.59) and accidents (HR 1.32, 95% CI 1.27-1.38). Such associations somewhat attenuated yet remained significant in the sibling analysis (HRs: 1.31 for any injury, 1.86 for suicidal behavior, and 1.29 for accidents). Additional adjustment for psychiatric comorbidities minimally altered the associations with any injury and accidents in both population and sibling analyses, whereas the association with suicidal behavior was considerably attenuated to non-significance in the sibling analysis. Such risks were particularly strong within 2 years after receiving the diagnosis of premenstrual disorders and were evident among women with premenstrual disorders with and without psychiatric comorbidities.

CONCLUSIONS

Our findings suggest that women with a clinical indication of premenstrual disorders are at increased subsequent risk of injury, particularly accidents within the first 2 years after diagnosis.

Mapping three versions of the international classification of diseases to categories of chronic conditions

INTRODUCTION

Administrative health data capture diagnoses using the International Classification of Diseases (ICD), which has multiple versions over time. To facilitate longitudinal investigations using these data, we aimed to map diagnoses identified in three ICD versions - ICD-8 with adaptations (ICDA-8), ICD-9 with clinical modifications (ICD-9-CM), and ICD-10 with Canadian adaptations (ICD-10-CA) - to mutually exclusive chronic health condition categories adapted from the open source Clinical Classifications Software (CCS).

METHODS

We adapted the CCS crosswalk to 3-digit ICD-9-CM codes for chronic conditions and resolved the one-to-many mappings in ICD-9-CM codes. Using this adapted CCS crosswalk as the reference and referring to existing crosswalks between ICD versions, we extended the mapping to ICDA-8 and ICD-10-CA. Each mapping step was conducted independently by two reviewers and discrepancies were resolved by consensus through deliberation and reference to prior research. We report the frequencies, agreement percentages and 95% confidence intervals (CI) from each step.

RESULTS

We identified 354 3-digit ICD-9-CM codes for chronic conditions. Of those, 77 (22%) codes had one-to-many mappings; 36 (10%) codes were mapped to a single CCS category and 41 (12%) codes were mapped to combined CCS categories. In total, the codes were mapped to 130 adapted CCS categories with an agreement percentage of 92% (95% CI: 86%-98%). Then, 321 3-digit ICDA-8 codes were mapped to CCS categories with an agreement percentage of 92% (95% CI: 89%-95%). Finally, 3583 ICD-10-CA codes were mapped to CCS categories; 111 (3%) had a fair or poor mapping quality; these were reviewed to keep or move to another category (agreement percentage = 77% [95% CI: 69%-85%]).

CONCLUSIONS

We developed crosswalks for three ICD versions (ICDA-8, ICD-9-CM, and ICD-10-CA) to 130 clinically meaningful categories of chronic health conditions by adapting the CCS classification. These crosswalks will benefit chronic disease studies spanning multiple decades of administrative health data.

Risk of Delayed Discharge and Reoperation of Gastric Bypass Patients with Psychiatric Comorbidity-a Nationwide Cohort Study

BACKGROUND

Gastric bypass (GBP) surgery is considered a safe and effective treatment for obesity. However, there is uncertainty regarding the impact of preexisting psychiatric comorbidity on GBP complications. We have investigated whether a psychiatric diagnosis before GBP surgery is associated with delayed discharge (the odds of being in the 90th percentile of length of stay) and rate of reoperation in a nationwide Swedish cohort.

METHODS

Patients undergoing GBP surgery during 2008-2012 were identified and followed up through the National Patient Register and the Prescribed Drug Register. Logistic regression models were fitted to the studied outcomes.

RESULTS

Among the 22,539 patients identified, a prior diagnosis of bipolar disorder, schizophrenia, depression, neurotic disorders, ADHD (attention deficit hyperactivity disorder), substance use disorder, eating disorder, personality disorder, or self-harm since 1997 (n = 9480) was found to be associated with delayed discharge after GBP surgery (odds ratio [OR] = 1.47, confidence interval [CI] 1.34-1.62), especially in patients with psychiatric hospitalization exceeding 1 week in the 2 years preceding GBP surgery (OR = 2.06, CI 1.30-3.28), compared with those not hospitalized within psychiatry. Likewise, patients with a prior psychiatric diagnosis were more likely to be reoperated within 30 days (OR = 1.25, CI 1.11-1.41), with twice the likelihood OR 2.23 (CI 1.26-3.92) for patients with psychiatric hospitalization of up to a week in the 2 years preceding GBP surgery, compared with patients who had not been hospitalized within psychiatry.

CONCLUSIONS

A psychiatric diagnosis before GBP surgery was associated with delayed discharge and increased likelihood of reoperation within 30 days. Patients with a prior psychiatric diagnosis may, therefore, need additional attention and support.

Association of etiological factors across the extreme end and continuous variation in disordered eating in female Swedish twins

BACKGROUND

Accumulating evidence suggests that many psychiatric disorders etiologically represent the extreme end of dimensionally distributed features rather than distinct entities. The extent to which this applies to eating disorders (EDs) is unknown.

METHODS

We investigated if there is similar etiology in (a) the continuous distribution of the Eating Disorder Inventory-2 (EDI-2), (b) the extremes of EDI-2 score, and (c) registered ED diagnoses, in 1481 female twin pairs at age 18 years (born 1992-1999). EDI-2 scores were self-reported at age 18. ED diagnoses were identified through the Swedish National Patient Register, parent-reported treatment and/or self-reported purging behavior of a frequency and duration consistent with DSM-IV criteria. We differentiated between anorexia nervosa (AN) and other EDs.

RESULTS

The heritability of the EDI-2 score was 0.65 (95% CI 0.61-0.68). The group heritabilities in DeFries-Fulker extremes analyses were consistent over different percentile-based extreme groups [0.59 (95% CI 0.37-0.81) to 0.65 (95% CI 0.55-0.75)]. Similarly, the heritabilities in liability threshold models were consistent over different levels of severity. In joint categorical-continuous models, the twin-based genetic correlation was 0.52 (95% CI 0.39-0.65) between EDI-2 score and diagnoses of other EDs, and 0.26 (95% CI 0.08-0.42) between EDI-2 score and diagnoses of AN. The non-shared environmental correlations were 0.52 (95% CI 0.32-0.70) and 0.60 (95% CI 0.38-0.79), respectively.

CONCLUSIONS

Our findings suggest that some EDs can partly be conceptualized as the extreme manifestation of continuously distributed ED features. AN, however, might be more distinctly genetically demarcated from ED features in the general population than other EDs.

Associations between individual antipsychotics and the risk of arrests and convictions of violent and other crime: a nationwide within-individual study of 74 925 persons

BACKGROUND

Individuals diagnosed with psychiatric disorders who are prescribed antipsychotics have lower rates of violence and crime but the differential effects of specific antipsychotics are not known. We investigated associations between 10 specific antipsychotic medications and subsequent risks for a range of criminal outcomes.

METHODS

We identified 74 925 individuals who were ever prescribed antipsychotics between 2006 and 2013 using nationwide Swedish registries. We tested for five specific first-generation antipsychotics (levomepromazine, perphenazine, haloperidol, flupentixol, and zuclopenthixol) and five second-generation antipsychotics (clozapine, olanzapine, quetiapine, risperidone, and aripiprazole). The outcomes included violent, drug-related, and any criminal arrests and convictions. We conducted within-individual analyses using fixed-effects Poisson regression models that compared rates of outcomes between periods when each individual was either on or off medication to account for time-stable unmeasured confounders. All models were adjusted for age and concurrent mood stabilizer medications.

RESULTS

The relative risks of all crime outcomes were substantially reduced [range of adjusted rate ratios (aRRs): 0.50-0.67] during periods when the patients were prescribed antipsychotics v. periods when they were not. We found that clozapine (aRRs: 0.28-0.44), olanzapine (aRRs: 0.46-0.72), and risperidone (aRRs: 0.53-0.64) were associated with lower arrest and conviction risks than other antipsychotics, including quetiapine (aRRs: 0.68-0.84) and haloperidol (aRRs: 0.67-0.77). Long-acting injectables as a combined medication class were associated with lower risks of the outcomes but only risperidone was associated with lower risks of all six outcomes (aRRs: 0.33-0.69).

CONCLUSIONS

There is heterogeneity in the associations between specific antipsychotics and subsequent arrests and convictions for any drug-related and violent crimes.

Patient educational level and management of bipolar disorder

BACKGROUND

Socioeconomic factors can affect healthcare management.

AIMS

The aim was to investigate if patient educational attainment is associated with management of bipolar disorder.

METHOD

We included patients with bipolar disorder type 1 (n = 4289), type 2 (n = 4020) and not otherwise specified (n = 1756), from the Swedish National Quality Register for Bipolar Disorder (BipoläR). The association between patients' educational level and pharmacological and psychological interventions was analysed by binary logistic regression. We calculated odds ratios after adjusting for demographic and clinical variables.

RESULTS

Higher education was associated with increased likelihood of receiving psychotherapy (adjusted odds ratio 1.34, 95% CI 91.22-1.46) and psychoeducation (adjusted odds ratio 1.18, 95% CI 1.07-1.46), but with lower likelihood of receiving first-generation antipsychotics (adjusted odds ratio 0.76, 95% CI 0.62-0.94) and tricyclic antidepressants (adjusted odds ratio 0.76, 95% CI 0.59-0.97). Higher education was also associated with lower risk for compulsory in-patient care (adjusted odds ratio 0.79, 95% CI 0.67-0.93).

CONCLUSIONS

Pharmacological and psychological treatment of bipolar disorder differ depending on patients' educational attainment. The reasons for these disparities remain to be explained.

Genetic and environmental sources of familial coaggregation of obsessive-compulsive disorder and suicidal behavior: a population-based birth cohort and family study

Obsessive-compulsive disorder (OCD) is associated with high risk of suicide. It is yet unknown whether OCD and suicidal behaviors coaggregate in families and, if so, what are the mechanisms underlying this coaggregation. In a population-based birth cohort and family study, we linked individuals born in Sweden in 1967-2003 (n = 3,594,181) to their parents, siblings, and cousins, and collected register-based diagnoses of OCD, suicide attempts, and deaths by suicide and followed them until December 31, 2013. We also applied quantitative genetic modeling to estimate the contribution of genetic and environmental factors to the familial coaggregation of OCD and suicidal behavior. An elevated risk of suicide attempts was observed across all relatives of individuals with OCD, increasing proportionally to the degree of genetic relatedness, with odds ratios (OR) ranging from 1.56 (95% confidence interval (CI) 1.49-1.63) in parents to 1.11 (95% CI 1.07-1.16) in cousins. The risk of death by suicide also increased alongside narrowing genetic distance, but was only significant in parents (OR 1.55; 95% CI 1.40-1.72) and full siblings (OR 1.80; 95% CI 1.43-2.26) of individuals with OCD. Familial coaggregation of OCD and suicide attempts was explained by additive genetic factors (60.7%) and non-shared environment (40.4%), with negligible contribution of shared environment. Similarly, familial coaggregation with death by suicide was attributed to additive genetics (65.8%) and nonshared environment (34.2%). Collectively, these observations indicate that OCD and suicidal behaviors coaggregate in families largely due to genetic factors. The contribution of unique environment is also considerable, providing opportunities to target high-risk groups for prevention and treatment.

Association Between Inflammatory Bowel Disease and Psychiatric Morbidity and Suicide: A Swedish Nationwide Population-Based Cohort Study With Sibling Comparisons

BACKGROUND AND AIMS

Inflammatory bowel disease [IBD] is linked to psychiatric morbidity, but few studies have assessed general population comparators. We aimed to investigate the risk of psychiatric morbidity and suicide in adult-onset IBD patients.

METHODS

We used a nationwide population-based cohort study in Sweden [1973-2013]. We studied the risk of psychiatric disorders and suicide in 69,865 adult-onset IBD patients [ulcerative colitis, UC: n = 43,557; Crohn's disease, CD: n = 21,245; and IBD-unclassified: n = 5063] compared to 3,472,913 general population references and 66 292 siblings.

RESULTS

During a median follow-up of 11 years, we found 7465 [10.7%] first psychiatric disorders in IBD [incidence rate, IR/1000 person-years 8.4] and 306 911 [9.9%] in the general population [IR 6.6], resulting in 1.8 extra psychiatric morbidity per 100 patients followed-up for 10 years and a hazard ratio [HR] of 1.3 [95% confidence interval, 95%CI = 1.2-1.3]. The highest risk of overall psychiatric morbidity was seen in the first year after IBD diagnosis [HR = 1.4, 95%CI = 1.2-1.6] and in patients with extraintestinal manifestations [HR = 1.6, 95%CI = 1.5-1.7]. Psychiatric morbidity was more common in all IBD subtypes [HR 1.3-1.5]. An increased risk of suicide attempts was observed among all IBD types [HR = 1.2-1.4], whereas completed suicide was explicitly associated with CD [HR = 1.5] and elderly-onset [diagnosed at the age of > 60 years] IBD [HR = 1.7].

CONCLUSION

Adult-onset IBD was associated with an increased risk of psychiatric disorders and suicide attempts. Psychological follow-up should be provided to patients with IBD, especially those with extraintestinal manifestations and elderly-onset IBD. This follow-up should be within the first year after IBD diagnosis.

Respiratory infections during lithium and valproate medication: a within-individual prospective study of 50,000 patients with bipolar disorder

BACKGROUND

In vitro studies have demonstrated that lithium has antiviral properties, but evidence from human studies is scarce. Lithium is used as a mood stabilizer to treat patients with bipolar disorder. Here, the aim was to investigate the association between lithium use and the risk of respiratory infections in patients with bipolar disorder. To rule out the possibility that a potential association could be due to lithium's effect on psychiatric symptoms, we also studied the effect of valproate, which is an alternative to lithium used to prevent mood episodes in bipolar disorder.

METHOD

We followed 51,509 individuals diagnosed with bipolar disorder in the Swedish Patient register 2005-2013. We applied a within-individual design using stratified Cox regression to estimate the hazard ratios (HRs) of respiratory infections during treated periods compared with untreated periods.

RESULTS

During follow-up, 5,760 respiratory infections were documented in the Swedish Patient Register. The incidence rate was 28% lower during lithium treatment (HR 0.73, 95% CI 0.61-0.86) and 35% higher during valproate treatment (HR 1.35, 95% CI 1.06-1.73) compared with periods off treatment.

CONCLUSIONS

This study provides real-world evidence that lithium is associated with decreased risk for respiratory infections and suggests that the repurposing potential of lithium for potential antiviral or antibacterial effects is worthy of investigation.

The Familial Risk of Autism Spectrum Disorder with and without Intellectual Disability

Autism spectrum disorder (ASD) is highly heritable, yet how its familial risk and heritability may vary by cognitive ability is not well understood. In this population‐based cohort study, we examined the familial risk and heritability of ASD with and without co‐occurring intellectual disability (ID). We estimated odds ratios and heritability of ASD with ID (ASD+ID) and ASD without ID (ASD−ID) using register‐based diagnosis data of 567,436 index persons born in 1984–2009 in Stockholm County, Sweden, and their parents, siblings, cousins, aunts, and uncles. The familial risk profile exhibited differences between ASD−ID and ASD+ID, most notably for index persons with affected parents. For example, for an index person who had at least one parent with ASD, the child's odds of ASD−ID and ASD+ID (95% confidence interval (CI)) increased by 16.2 (14.2–18.6) and 7.4 (5.5–10.0) folds, respectively. The more closely related a family member with ASD was, the greater the observed risk was of ASD in the index person, especially for ASD−ID. The broad‐sense heritability (95% CI) for ASD − ID and ASD+ID were 64.6% (46.0–100.0%) and 33.4% (14.4–58.4%), respectively. Familial risk and heritability of ASD may vary by intellectual ability, which implies that risk factors between these ASD phenotypes may differ. Our findings from the heritability analysis and familial risk analysis suggest that ASD−ID may have a greater genetic basis than ASD+ID, although this should be verified in future studies.

Lay Summary

Autism spectrum disorder (ASD) is highly heritable, yet how its familial risk and heritability may vary by cognitive ability is not well‐understood. In a population‐based cohort study on families of 567,436 index persons using Swedish registers data, we found that the familial risk profile differed between ASD with and without intellectual disability. Our findings from the heritability analysis and familial risk analysis suggest that ASD−ID may have a greater genetic basis than ASD+ID, although this should be verified in future studies.

Nonsyndromic Craniosynostosis Is Associated with Increased Risk for Psychiatric Disorders

BACKGROUND

Craniosynostosis is one of the most common craniofacial malformations demanding surgical treatment in infancy. Data on overall psychiatric morbidity among children with nonsyndromic craniosynostosis remain limited. This study investigated the risk of psychiatric disorders in nonsyndromic craniosynostosis.

METHODS

The authors reviewed a register-based cohort of all individuals born with nonsyndromic craniosynostosis in Sweden between 1973 to 1986 and 1997 to 2012 (n = 1238). The nonsyndromic craniosynostosis cohort was compared with a matched community cohort (n = 12,380) and with unaffected full siblings (n = 1485). The authors investigated the risk of psychiatric disorders, suicide attempts, and suicides by using Cox regression adjusted for perinatal and somatic factors, season and birth year, sex, parental socioeconomic factors, and parental psychiatric disorders.

RESULTS

Children with nonsyndromic craniosynostosis had a higher risk of any psychiatric disorder (adjusted Cox-derived hazard ratio, 1.70; 95 percent CI, 1.43 to 2.02), including intellectual disability (adjusted Cox-derived hazard ratio, 4.96; 95 percent CI, 3.20 to 7.70), language disorders (adjusted Cox-derived hazard ratio, 2.36; 95 percent CI, 1.57 to 3.54), neurodevelopmental disorders (adjusted Cox-derived hazard ratio, 1.30; 95 percent CI, 1.01 to 1.69), and other psychiatric disorders (adjusted Cox-derived hazard ratio, 1.43; 95 percent CI, 1.11 to 1.85). Full siblings with nonsyndromic craniosynostosis were more likely, in the crude analyses, to be diagnosed with any psychiatric disorder, including intellectual disability, language disorders, and neurodevelopmental disorders compared with nonaffected siblings. The higher risk for any psychiatric disorder and intellectual disability remained after adjusting for confounders.

CONCLUSIONS

Children with nonsyndromic craniosynostosis demonstrated higher risks of any psychiatric disorder compared with children without nonsyndromic craniosynostosis. This risk cannot fully be explained by familial influences (i.e., genetic or environmental factors).

CLINICAL QUESTION/LEVEL OF EVIDENCE

Risk, III.

Suicide mortality after discharge from inpatient care for bipolar disorder: A 14-year Swedish national registry study

Bipolar disorder has long been associated with increased risks for suicidality; though factors associated with dying by suicide remain obscure. Here, we retrospectively examine the associations between the different phases of bipolar illness and other common comorbidities with death by suicide in the 120 days following each discharge for Swedes first admitted as inpatients for bipolar disorder during the years 2000-2014. Data on admissions and suicide deaths were extracted from the Swedish National Patient Register and the Cause of Death Register, respectively. ICD-10 diagnostic codes were used to define the phases: depressive, manic, mixed, and other; and the comorbidities: specific substance use disorders, attention deficit hyperactivity disorder, and personality disorders. Extended Cox regressions were employed to model the time to death by suicide as a function of the bipolar phases, comorbidities, and other important control variables. Our analysis included 60,643 admissions by 22,402 patients over an observation time of 15,187 person-years. Overall, 213 (35.7%) of all suicides occurred within 120 days of discharge. Upon adjustment and compared to the depressive phases, manic phases were significantly associated with a far lower hazard of dying by suicide (HR 0.34, 95% CI: 0.21-0.56, p < 0.001), though mixed phases were not (HR 0.92, 95% CI: 0.48-1.73, p = 0.957). With regard to comorbidity, only sedative use disorder remained significantly associated with dying by suicide upon adjustment (HR 2.08, 95% CI: 1.41-3.06, p = 0.001). Vigilant monitoring of patients post discharge and of prescription practices are recommended.