The Danish psychiatric register as a tool in epidemiology

Use of the French national health insurance information system for research in the field of mental health: Systematic review and perspectives

PURPOSE

This systematic review registered in PROSPERO (CRD42021225296) aimed to describe the use of the French national health insurance information system, which covers the entire French population (67 million inhabitants), for research in the field of mental health.

METHODS

Three electronic databases and a journal hand-search identified 15 265 articles from January 1, 2003 (year of creation of the database) to October 31, 2020. Studies of any design were eligible for inclusion provided that they (i) made use of at least one component of the French health insurance database and (ii) focused on a topic in near and far connection with the field of mental health in France. Database used, design and methods, study period, population, key findings, and type of use for medical research were described.

RESULTS

A total of 152 studies were included in the review analysis. There was an increase in the number of published articles over time throughout the studied period. Studies focusing on adults (n = 139) largely outnumbered those focusing on children and adolescents (n = 11). Pharmacoepidemiological studies were by far the most frequent (n = 123), followed by methodological studies (n = 23), epidemiological studies (n = 17), and health economics studies (n = 3). The most studied psychotropic drugs were antidepressants (n = 27), anxiolytics (n = 27), and opioids (n = 25) while fewer studies focused on methylphenidate (n = 6) and on mood stabilizers (n = 5). Few studies specifically focused on psychiatric disorders, mainly depression (n = 4), suicide (n = 4), and psychotic disorders (n = 3).

CONCLUSION

This systematic review highlighted a relatively poor exploitation of the Système national des données de santé database in the field of psychiatric research with regard to the great possibilities it offers, with a clear lag in certain fields such as epidemiological or health economics studies and in specific populations, in particular children and adolescents.

Early Life Exposure to Perfluoroalkyl Substances (PFAS) and ADHD: A Meta-Analysis of Nine European Population-Based Studies

INTRODUCTION

To date, the evidence for an association between perfluoroalkyl substances (PFAS) exposure and attention deficit and hyperactivity disorder (ADHD) is inconclusive.

OBJECTIVE

We investigated the association between early life exposure to perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA), and ADHD in a collaborative study including nine European population-based studies, encompassing 4,826 mother-child pairs.

METHODS

Concentrations of PFOS and PFOA were measured in maternal serum/plasma during pregnancy, or in breast milk, with different timing of sample collection in each cohort. We used a validated pharmacokinetic model of pregnancy and lactation to estimate concentrations of PFOS and PFOA in children at birth and at 3, 6, 12, and 24 months of age. We classified ADHD using recommended cutoff points for each instrument used to derive symptoms scores. We used multiple imputation for missing covariates, logistic regression to model the association between PFAS exposure and ADHD in each study, and combined all adjusted study-specific effect estimates using random-effects meta-analysis.

RESULTS

A total of 399 children were classified as having ADHD, with a prevalence ranging from 2.3% to 7.3% in the studies. Early life exposure to PFOS or PFOA was not associated with ADHD during childhood [odds ratios (ORs) ranging from 0.96 (95% CI: 0.87, 1.06) to 1.02 (95% CI: 0.93, 1.11)]. Results from stratified models suggest potential differential effects of PFAS related to child sex and maternal education.

CONCLUSION

We did not identify an increased prevalence of ADHD in association with early life exposure to PFOS and PFOA. However, stratified analyses suggest that there may be an increased prevalence of ADHD in association with PFAS exposure in girls, in children from nulliparous women, and in children from low-educated mothers, all of which warrant further exploration. https://doi.org/10.1289/EHP5444.

The organization of the psychiatric service and criminality committed by the mentally ill

Introduction

Over the past 40 years, a marked deinstitutionalisation in favour of social and community psychiatry has taken place in many countries. During this same period of time, there has been an increase in the number of mentally ill criminals. The purpose of this study is to analyse the correlations between the reorganization of the psychiatric treatment system, the growing number of forensic patients and the increase in serious crime, homicide, arson and violence associated with the mentally ill.

Materials and methods

Using registers and other data sources, we estimated the annual positive or negative growth rate of consumed psychiatric beds and in social and community psychiatry (explanatory variables) and in prevalence and incidence of forensic patients, homicide, arson and violence (response variables) from 1980 to 1997 for each of the Danish counties. We analysed the immediate effect of the changing treatment structure by relating response variables to explanatory variables. The long-term effect was analysed in the form of between county analysis with both single and multiple regressions.

Results

Bed closure had no immediate effect on either the number of forensic patients or serious criminality. The between county analysis shows, however, that over time the (negative) growth rate in number of consumed beds is significantly correlated with the (positive) growth rates for forensic patients, homicide and arson. Social and community psychiatry have little effect, if any.

Discussion

The study is based on historical data, but the results are still valid. We have used two sets of data firstly the number of forensic patients and, secondly the reported number of crimes associated with the mentally ill. The uniformity of the results leads us to consider them for certain: That the decreasing effort invested in inpatient treatment is causing an increase in the crime rate among the mentally ill.

Conclusion

Many forensic patients suffer from schizophrenia. These patients are not only offenders, but also the victims of an inadequate treatment system. Modern inpatient treatment facilities should be established.

Incipient offending among schizophrenia patients after first contact to the psychiatric hospital system

The study examines how age, sex and substance use disorder are associated with the risk of committing a criminal offence. The study explicitly examines the risk after the first contact to the psychiatric hospital system and after the diagnosis of schizophrenia for those with no previous criminal record; the association between previous non-violent criminality and later violent criminality is also analysed. The study sample comprised 4619 individuals ever diagnosed with schizophrenia. All solved offences were accessible. Data were analysed using Cox's regression. Schizophrenic men had twice the risk of schizophrenic women of committing both violent and non-violent offences. A registered substance use disorder increased the risk 1.9- to 3.7-fold, depending on the starting point for the analyses, while increasing age on first contact or when diagnosed with schizophrenia diminished the risk. Previous non-violent criminality increased the risk for later violent criminality 2.5- to 2.7-fold, depending on the starting point for the analyses. The results suggest that the psychiatric treatment system can play an active role in preventing criminality among individuals with schizophrenia. The preventive measures should be based on a thorough assessment including criminal history at intake and alertness toward young psychotic men with substance use disorders and especially if they also have a criminal history.

Association of Grandparental and Parental Age at Childbirth With Autism Spectrum Disorder in Children

IMPORTANCE

Advanced parental age has been associated with autism spectrum disorders (ASDs) in children. However, little is known about the association between grandparental age at the time of birth of the parent and the risk of ASD in the grandchildren.

OBJECTIVE

To estimate the associations between parental and grandparental age and ASD risk in children.

DESIGN, SETTING, AND PARTICIPANTS

This population-based, multigenerational cohort study used data from Danish national health registries. A parental age cohort was constructed to evaluate the association between parental age and ASD in 1 476 783 singleton children born from 1990 to 2013, and a multigenerational cohort was also constructed including 362 438 fathers and 458 234 mothers born from 1973 to 1990 for whom information on grandparental age was available. Data analyses were conducted from November 1, 2018, through February 7, 2020.

EXPOSURES

Parental age at childbirth and grandparental age at the time of the birth of the parent.

MAIN OUTCOMES AND MEASURES

Diagnoses of ASD in children were obtained from the Danish Psychiatric Central Register (1994-2017). Logistic regression analysis was used to estimate the associations between parental or grandparental age and ASD in children.

RESULTS

Of the 1 476 783 children born from 1990 to 2013, 758 066 (51.3%) were male, and 27 616 (1.9%) had ASD (20 467 [74.1%] were male). Advanced paternal or maternal age over 30 years was monotonically associated with increased ASD risk, with odds ratios (ORs) of 1.56 (95% CI, 1.45-1.68) for maternal age 40 years and older and 1.57 (95% CI, 1.39-1.78) for paternal age 50 years and older, compared with parents aged 25 to 29 years. In the multigenerational cohort, 9364 grandchildren (1.7%) had ASD. This study found U-shaped associations, in that ASD risk was higher among grandchildren of younger (≤19 years) maternal grandmothers (OR, 1.68; 95% CI, 1.52-1.85), younger maternal grandfathers (OR, 1.50; 95% CI, 1.26-1.78), and younger paternal grandmothers (OR, 1.18; 95% CI, 1.04-1.34), and older (≥40 years) paternal grandmothers (OR, 1.40; 95% CI, 1.03-1.90) compared with the grandchildren of grandparents who were aged 25 to 29 years at the time of giving birth to the parents.

CONCLUSIONS AND RELEVANCE

These findings corroborate previous studies suggesting that advanced parental age is independently associated with increased ASD risk in children. This study also found that children with young maternal grandparents and children with young and old paternal grandparents had elevated ASD risk. Possible transmission of ASD risk across generations should be considered in etiological research on ASD.

Premature mortality in persons with epilepsy and schizophrenia: A population-based nationwide cohort study

OBJECTIVE

To determine the mortality for persons with epilepsy and schizophrenia by absolute and relative measures.

METHODS

This is a population-based nationwide cohort study of persons born in Denmark from 1960 to 1987 who were alive and residing in Denmark on their 25th birthday. We identified persons diagnosed with epilepsy and schizophrenia prior to their 25th birthday and followed them to death, emigration, or December 31, 2012, whichever came first. The primary outcome was overall mortality. Data were analyzed using Cox regressions.

RESULTS

Persons were followed for 24 167 573 person years; the median was 15 years. The mortality rate ratio was 4.4 (95% confidence interval [CI] = 4.1-4.7) for persons with epilepsy, 6.6 (95% CI = 6.1-7.1) for persons with schizophrenia, and 12.8 (95% CI = 9.1-18.1) for persons with both disorders, compared with persons without these disorders. The estimated cumulative mortality at the age of 50 years was 3.1% (95% CI = 3.0-3.1) for persons without epilepsy and schizophrenia, 10.7% (95% CI = 9.7-11.8) for persons with epilepsy, 17.4% (95% CI = 16.0-18.8) for persons with schizophrenia, and 27.2% (95% CI = 15.7-40.1) for persons with both disorders.

SIGNIFICANCE

Persons with epilepsy and schizophrenia have very high mortality; more than one in four persons with both disorders died between the age of 25 and 50 years, indicating that these patients need special clinical attention.

Stress Disorders and Dementia in the Danish Population

There is an association between stress and dementia. However, less is known about dementia among persons with varied stress responses and sex differences in these associations. We used this population-based cohort study to examine dementia among persons with a range of clinician-diagnosed stress disorders, as well as the interaction between stress disorders and sex in predicting dementia, in Denmark from 1995 to 2011. This study included Danes aged 40 years or older with a stress disorder diagnosis (n = 47,047) and a matched comparison cohort (n = 232,141) without a stress disorder diagnosis with data from 1995 through 2011. Diagnoses were culled from national registries. We used Cox proportional hazards regression to estimate associations between stress disorders and dementia. Risk of dementia was higher for persons with stress disorders than for persons without such diagnosis; adjusted hazard ratios ranged from 1.6 to 2.8. There was evidence of an interaction between sex and stress disorders in predicting dementia, with a higher rate of dementia among men with stress disorders except posttraumatic stress disorder, for which women had a higher rate. Results support existing evidence of an association between stress and dementia. This study contributes novel information regarding dementia risk across a range of stress responses, and interactions between stress disorders and sex.

Effectiveness of maintenance therapy of lithium vs other mood stabilizers in monotherapy and in combinations: a systematic review of evidence from observational studies

OBJECTIVES

For the first time to present a systematic review of observational studies on the efficiency of lithium monotherapy in comparison with other maintenance mood stabilizers in monotherapy and in combination.

METHODS

As part of the International Society for Bipolar Disorders (ISBD) Task Force on Lithium Treatment, we undertook a systematic literature search of non-randomized controlled observational studies on (i) lithium monotherapy vs treatment with another maintenance mood stabilizer in monotherapy and (ii) lithium in combination with other mood stabilizers vs monotherapy.

RESULTS

In eight out of nine identified studies including a total of < 14 000 patients, maintenance lithium monotherapy was associated with improved outcome compared with another mood stabilizer in monotherapy, including valproate, lamotrigine, olanzapine, quetiapine, unspecified anticonvulsants, carbamazepine/lamotrigine, unspecified atypical antipsychotics and unspecified antipsychotics. Among the four identified studies including a total of > 4000 patients comparing maintenance combination therapy with maintenance monotherapy, a few combination therapies were found to be superior to monotherapy in some analyses, but many were not.

CONCLUSIONS

The results show the superiority in real life of lithium monotherapy compared with monotherapy with other maintenance mood stabilizers. The four largest register-based studies largely addressed confounding, but, as ever, residual confounding cannot be excluded. Nevertheless, the observational findings substantially add to the findings from randomized controlled trials, whose designs often limit the validity of comparison between medicines.

Prevalence and prognosis of stress disorders: a review of the epidemiologic literature

Given the ubiquity of traumatic events, it is not surprising that posttraumatic stress disorder (PTSD) - a common diagnosis following one of these experiences - is characterized as conferring a large burden for individuals and society. Although there is recognition of the importance of PTSD diagnoses throughout psychiatry, the literature on other diagnoses one may receive following a stressful or traumatic event is scant. This review summarizes the literature on stress disorders (classified according to the International Classification of Diseases, 10th Edition [ICD-10]), including acute stress reaction, PTSD, adjustment disorder and unspecified stress reactions. This review focuses on the literature related to common psychiatric and somatic consequences of these disorders. The prevalence and incidence of each disorder are described. A review of epidemiologic studies on comorbid mental health conditions, including depression, anxiety and substance abuse, is included, as well as a review of epidemiologic studies on somatic outcomes, including cancer, cardiovascular disease and gastrointestinal disorders. Finally, the current literature on all-cause mortality and suicide following stress disorder diagnoses is reviewed. Stress disorders are a critical public health issue with potentially deleterious outcomes that have a significant impact on those living with these disorders, the health care system and society. It is only through an awareness of the impact of stress disorders that appropriate resources can be allocated to prevention and treatment. Future research should expand the work done to date beyond the examination of PTSD, so that the field may obtain a more complete picture of the impact all stress disorders have on the many people living with these diagnoses.

Attention deficit/hyperactivity disorder and childhood autism in association with prenatal exposure to perfluoroalkyl substances: a nested case-control study in the Danish National Birth Cohort

BACKGROUND

Perfluoroalkyl substances (PFASs) are persistent pollutants found to be endocrine disruptive and neurotoxic in animals. Positive correlations between PFASs and neurobehavioral problems in children were reported in cross-sectional data, but findings from prospective studies are limited.

OBJECTIVES

We investigated whether prenatal exposure to PFASs is associated with attention deficit/hyperactivity disorder (ADHD) or childhood autism in children.

METHODS

Among 83,389 mother-child pairs enrolled in the Danish National Birth Cohort during 1996-2002, we identified 890 ADHD cases and 301 childhood autism cases from the Danish National Hospital Registry and the Danish Psychiatric Central Registry. From this cohort, we randomly selected 220 cases each of ADHD and autism, and we also randomly selected 550 controls frequency matched by child's sex. Sixteen PFASs were measured in maternal plasma collected in early or mid-pregnancy. We calculated risk ratios (RRs) using generalized linear models, taking into account sampling weights.

RESULTS

Perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) were detected in all samples; four other PFASs were quantified in ≥ 90% of the samples. We did not find consistent evidence of associations between mother's PFAS plasma levels and ADHD [per natural log nanograms per milliliter increase: PFOS RR = 0.87 (95% CI: 0.74, 1.02); PFOA RR = 0.98 (95% CI: 0.82, 1.16)] or autism [per natural log nanograms per milliliter increase: PFOS RR = 0.92 (95% CI: 0.69, 1.22); PFOA RR = 0.98 (95% CI: 0.73, 1.31)]. We found positive as well as negative associations between higher PFAS quartiles and ADHD in models that simultaneously adjusted for all PFASs, but these estimates were imprecise.

CONCLUSIONS

In this study we found no consistent evidence to suggest that prenatal PFAS exposure increases the risk of ADHD or childhood autism in children.

Neuroticism in Remitted Major Depression: Elevated with Early Onset but Not Late Onset of Depression

BACKGROUND

The personality trait of neuroticism is strongly related to depression, but depression is etiologically heterogeneous. Late-onset depression (LOD) may be more closely related to vascular factors, and previous studies of neuroticism in LOD versus early-onset depression (EOD) have not been consistent.

METHOD

We examined neuroticism, extraversion and perceived stress in 88 fully remitted depressed patients with a mean age of 60 years and with a history of hospitalization for major depressive disorder. Patients were divided into those with onset after and those with onset before 50 years of age (LOD and EOD, respectively), and the two groups were compared both with each other and with matched control groups of healthy subjects.

RESULTS

EOD patients showed increased levels of neuroticism in comparison with both LOD and matched controls, who did not differ. The association between age of onset and neuroticism was confirmed in analyses based on age of depression onset as a continuous variable.

CONCLUSION

Neuroticism may be an etiological factor in EOD but not or less so in LOD. This finding contributes to the growing evidence for etiological differences between early- and late-onset late-life depression.

Maternal depression, antidepressant use in pregnancy and Apgar scores in infants

BACKGROUND

Use of antidepressants during pregnancy has been associated with a low Apgar score in infants but a contribution from the underlying depressive disorder might influence this association.

AIMS

To estimate the effects of maternal depression and use of antidepressants during pregnancy on low Apgar scores (<7) 5 min after birth.

METHOD

Register study on all pregnant women in Denmark from 1996 to 2006 linking nationwide individualised data from the Medical Birth Register, the Psychiatric Central Register and the National Prescription database.

RESULTS

Infants exposed to antidepressants during pregnancy had an increased rate of a low Apgar score (odds ratio (OR) = 1.72, 95% CI 1.34-2.20). The increased rate was only found among infants exposed to selective serotonin reuptake inhibitors (SSRIs) (OR = 1.96, 95% CI 1.52-2.54), not among those exposed to newer (OR = 0.83, 95% CI 0.40-1.74) or older antidepressants (OR = 0.53, 95% CI 0.19-1.45). Maternal depression before or during pregnancy, without prescription of antidepressants, was not associated with a low Apgar score (OR = 0.44, 95% CI 0.11-1.74). Women who had only used antidepressants prior to pregnancy had no increased rate of a low Apgar score in their subsequent pregnancy, regardless of depression status.

CONCLUSIONS

Use of SSRIs during pregnancy increases the risk of a low Apgar score independently of maternal depression.

Decreasing rates of incident schizophrenia cases in psychiatric service: A review of the literature

A review of the literature shows that the admission rates of new cases of schizophrenia vary with a factor of two to five in North American studies as well as in European studies. Furthermore, the tendency has been decreasing for the last 40-50 years in Europe. Eighteen studies specifically analyzing the development over the last 20 years are reviewed. The studies preponderantly show significant decreases most probably due to the reduction of the number of available psychiatric beds alongside the decentralization of psychiatry, and to decreasing virulence of schizophrenia. Alternatively, a diagnostic delay of schizophrenia can hardly explain the decrease.

Validity of diagnoses and other clinical register data in patients with affective disorder

Studies validating the clinical diagnoses of affective disorder recorded in case registers against research diagnostic criteria do not exist. In the present study, a random sample of 100 patients was selected among 21,734 patients who were recorded in the Danish Psychiatric Central Register with a diagnosis of manic-depressive psychosis at their first admission to psychiatric ward in a period from January 1, 1971 to December 31, 1993. Case notes from alt over Denmark were reviewed for all 100 patients and diagnoses were made with the use of OPCRIT. Patients who were still alive were contacted and interviewed face to face or by telephone. In total, 95 out of the 100 patients received an ICD-10 diagnosis of affective disorder computed with OPCRIT and confirmed at the interviews. Other clinical characteristics such as the age at onset and the number of affective episodes estimated from the register corresponded well with information from the case notes and the interviews.

Decreased levels of brain-derived neurotrophic factor in the remitted state of unipolar depressive disorder

OBJECTIVE

Decreased levels of peripheral brain-derived neurotrophic factor (BDNF) have been associated with depression. It is uncertain whether abnormally low levels of BDNF in blood are present beyond the depressive state and whether levels of BDNF are associated with the course of clinical illness.

METHOD

Whole-blood BDNF levels were measured in blood samples from patients with unipolar disorder in a sustained state of clinical remission and in a healthy control group. Participants were recruited via Danish registers, a method that benefits from the opportunity to obtain well-matched community-based samples as well as providing a high diagnostic validity of the patient sample.

RESULTS

A total of 85 patients and 50 controls were included in the study. In multiple linear regression analyses, including the covariates age, gender, 17-item Hamilton Depression Rating Scale scores, body-mass index, education, smoking and physical exercise, patients with unipolar depressive disorder had decreased levels of BDNF compared to healthy control individuals [B = -7.4, 95% CI (-11.2, -3.7), = 0.21 P < 0.001]. No association between course of clinical illness and BDNF levels was present.

CONCLUSION

Whole-blood BDNF levels seem to be decreased in patients remitted from unipolar depressive disorder, suggesting that neurotrophic changes may exist beyond the depressive state.

The cumulative load of depressive illness is associated with cognitive function in the remitted state of unipolar depressive disorder

OBJECTIVE

To investigate whether the cumulative number, duration and subtypes (severity and presence of psychotic features) of previous episodes of depression in patients with unipolar depressive disorder in a remitted state are associated with decreased global cognitive function.

METHODS

Via the Danish registers individuals between 40 and 80 years of age were identified: (1) patients with a diagnosis of unipolar disorder at their first discharge from a psychiatric hospital in the period 1994 to 2002, and (2) gender and age matched control individuals. The participants were assessed with the Cambridge Cognitive Examination (CAMCOG), which provides a composite measure of global cognitive function.

RESULTS

A total of 88 patients and 50 controls accepted our invitation to participate, fulfilled the selection criteria and were included in the study. The cumulative duration of depressive episodes was associated with a decreased CAMCOG score adjusted for age, gender, education, premorbid IQ and residual depressive symptoms (B=-0.14, 95% C.I. (-0.26, -0.02), R(2)adj=0.31, P=.02). Significant associations were also found between CAMCOG score and the cumulative duration and total number of depressive episodes with psychotic features, respectively.

CONCLUSION

Our findings suggest that cognitive dysfunction is associated with the cumulative duration of depressive episodes, and that, in particular, depressive episodes with psychotic features in the course of illness may be a significant predictor of future impairment of cognitive function.

Lack of association between prior depressive episodes and cerebral [11C]PiB binding

Depressive symptoms are frequent in Alzheimer's disease (AD), but it is controversial whether depression is a risk factor for AD. This study measured for the first time cortical amyloid-β (Aβ) levels using [(11)C] Pittsburgh Compound B (PiB) positron emission tomography (PET) in a group of nondemented patients with prior depressive episodes. Twenty-eight elderly patients (mean age 61 years, range 51-75, 18 women) with onset of first depressive episode more than 6 years ago but now remitted from depression and 18 healthy subjects (mean age 61 years, range 50-76, 12 women) were included. All subjects were investigated with cognitive testing, 3T magnetic resonance imaging (MRI) and [(11)C]PiB high resolution research tomography (HRRT) positron emission tomography scan. There was no between-groups difference in [(11)C]PiB binding (p = 0.5) and no associations to number of depressive episodes, cognitive performance, or antidepressant treatment. Patients with late onset of depression had increased severity of white matter lesions (p = 0.04). In this study depressive episodes were not associated with increased levels of [(11)C]PiB. Thus, our results do not support the notion that depressive episodes previously in life are a risk factor for developing AD.

Electroconvulsive therapy for treating schizophrenia: a chart review of patients from two catchment areas

To examine disease and treatment characteristics of patients with schizophrenia treated with electroconvulsive therapy (ECT). We examined charts from 79 patients diagnosed with schizophrenia (n = 55), persistent delusional disorders (n = 7), and schizoaffective disorders (n = 17) between 2003 and 2008. We recorded age, sex, indication for ECT, number of ECT sessions, ECT series, outcome, maintenance ECT, use of antipsychotics, duration of illness, and duration of the current exacerbation. All patients were taking antipsychotics at the time of enrolment in the study. Acute ECT included 2-26 sessions; maintenance ECT (M-ECT) was given to 18 patients for up to 12 years. Initial indications for ECT included psychosis (n = 28), pronounced affective symptoms (n = 28), delirious states (n = 20), and M-ECT (n = 3). Most patients experienced excellent/good outcomes (n = 66), but others experienced moderate (n = 8) or poor (n = 5) outcomes. No factors were identified that predicted treatment responses in individual patients. ECT proved to be effective in a population of patients that were severely ill with treatment-refractory schizophrenia. This does not imply that the patients were cured from schizophrenia. Rather, it reflects the degree of relief from psychosis and disruptive behaviour, as described in the patient charts. The treatment was often offered to patients after considerable disease durations.

The risk of psychiatric disorders in individuals born prematurely in Denmark from 1974 to 1996

AIM

To investigate the risk of developing psychiatric disorders in individuals born prematurely (born before 37 weeks of gestation).

METHODS

The study is a longitudinal register-based study including all live-born individuals in Denmark from 1974 to 1996. Poisson regression models including well-known confounders were used to investigate the rate ratio of psychiatric disorders at the age of 11-34 years in the individuals born prematurely.

RESULTS

A total of 1,545,641 individuals were born from 1974 to 1996. Of these, 1,348,106 live-born individuals constituted the study cohort. Rate ratios of psychiatric disorders, in total, increased in proportion to the degree of prematurity. The rate ratio of major psychiatric disorder was increased in individuals born with a gestational age below 28 weeks compared to persons born with a gestational age of 39-45 weeks (RR = 1.88 (95% CI: 1.25-2.83)). Similarly, the rate ratios of minor psychiatric disorder (RR = 1.63 (95% CI: 1.29-2.06)) and psychotropic drugs purchased (RR = 1.35 (95% CI: 0.98-1.86)) were increased.

CONCLUSION

The risk of minor as well as major psychiatric disorders during adolescence and young adulthood increases in proportion to the degree of prematurity. The relative risk, however, is small compared to the risks of cerebral palsy or low intelligence.

The association between preschool behavioural problems and internalizing difficulties at age 10-12 years

The aim was to study the association between preschool behavioural problems and emotional symptoms in 10- to 12-year-old children. The study was based on the Aarhus Birth cohort, Denmark, and included 1,336 children. Based on the parent-administered preschool behaviour questionnaire (PBQ), we identified three not mutually exclusive preschool behavioural categories: anxious-fearful (n = 146), hyperactive-distractible (n = 98), and hostile-aggressive (n = 170). Children without any known symptoms were considered well adjusted (n = 1,000). Borderline emotional (n = 105) and emotional difficulties (n = 136) were measured at age 10-12 years with the parent-administered strength and difficulties questionnaire (SDQ). Multinomial logistic regression analyses were used to adjust for potential confounding factors. We found that anxious-fearful behaviour and hostile-aggressive preschool behaviour were associated with twice the risk of school-age emotional difficulties. Comorbidity or confounding failed to explain these results. Hyperactive-distractible preschool behaviour was not associated with school-age emotional difficulties. Preschool anxious-fearful behaviour was associated with school-age emotional difficulties, suggesting internalizing symptom stability in some children from early childhood. Preschool hostile-aggressive behaviour was also associated with school-age emotional difficulties, which suggests transformation of one behavioural dimension into another through childhood, and the need to focus on both early internalizing difficulties and hostile-aggressive behaviour as risk factors for later internalizing difficulties.

Autoimmune diseases, bipolar disorder, and non-affective psychosis

OBJECTIVE

Clinic-based studies of immune function, as well as comorbidity of autoimmune diseases, bipolar disorder, and schizophrenia, suggest a possible autoimmune etiology. Studies of non-affective psychosis and schizophrenia suggest common etiologies. The objective was to determine the degree to which 30 different autoimmune diseases are antecedent risk factors for bipolar disorder, schizophrenia, and non-affective psychosis.

METHODS

A cohort of 3.57 million births in Denmark was linked to the Psychiatric Case Register and the National Hospital Register. There were 20,317 cases of schizophrenia, 39,076 cases of non-affective psychosis, and 9,920 cases of bipolar disorder.

RESULTS

As in prior studies, there was a range of autoimmune diseases which predicted raised risk of schizophrenia in individuals who had a history of autoimmune diseases, and also raised risk in persons whose first-degree relatives had an onset of autoimmune disease prior to onset of schizophrenia in the case. These relationships also existed for the broader category of non-affective psychosis. Only pernicious anemia in the family was associated with raised risk for bipolar disorder (relative risk: 1.7), suggesting a small role for genetic linkage. A history of Guillain-Barré syndrome, Crohn's disease, and autoimmune hepatitis in the individual was associated with raised risk of bipolar disorder.

CONCLUSIONS

The familial relationship of schizophrenia to a range of autoimmune diseases extends to non-affective psychosis, but not to bipolar disorder. The data suggest that autoimmune processes precede onset of schizophrenia, but also non-affective psychosis and bipolar disorder.

The use of population based registers in psychiatric research

OBJECTIVE

Much of the knowledge we now take for granted regarding major mental disorders such as schizophrenia, suicide and other disorders, would not exist without the use of population based registers. The use of population based registers in psychiatric epidemiology have enabled analyses of associations that otherwise would not have been possible to address.

METHOD

The use of registers in psychiatric research is described, exemplified, and discussed.

RESULTS

Methodological and validity aspects depend to a large part on the type of register being considered. A classification is proposed of different types of registers, each one implying specific methodological issues. These can be addressed according to the dimensions coverage, attrition, representativity and validity. Specific methodological consideration has still to be taken in relation to each specific research question. Thus, special validity studies usually need to be performed when embarking on studies using population based registers.

CONCLUSION

With increasing burden of disease due to mental disorders worldwide, knowledge of the epidemiology of these disorders are of increasing interest. The Nordic countries have a strong history in this field of research, of great interest to the rest of the world. Universities and research funding agencies should recognize this valuable source of research capacity, and support fruitful continuation of a strong tradition.

Registered criminality and sanctioning of schizophrenia patients

BACKGROUND

Patients with schizophrenia have been shown to have an increased risk of criminality, especially violent crimes.

AIMS

The aim of the current study was to describe the pattern of crimes committed by Danish patients with schizophrenia and examine the sanctions given for crimes in relation to the different periods in the patients' lives: not yet known to the psychiatric hospital system, known to the system but not yet diagnosed with schizophrenia, and after being diagnosed with schizophrenia.

METHODS

Information from the Danish Psychiatric Central Research Register was correlated with data from the Danish National Crime Register.

RESULTS

One of the more prominent findings was that 16% of patients diagnosed with schizophrenia receive a prison sentence or a suspended prison sentence, despite the fact that Denmark is a co-signatory of the European Prison Rules and should treat, rather than imprison, individuals with schizophrenia.

CONCLUSION

The findings suggest that greater alertness is needed in the judicial system for individuals diagnosed with schizophrenia.

Misclassification and the use of register-based indicators for depression

OBJECTIVE

To study the degree to which depression indicators based on register data on hospital and antidepressant treatment suffer from differential misclassification with respect to gender, age and social group.

METHOD

Data on 7378 persons were obtained by linking a cross-sectional survey of Danish adults aged 40 and 50 years with population-based registers. Misclassification was analysed by comparing survey data to register data on major depression using the method proposed by Rothman and Greenland.

RESULTS

Differential misclassification was found. Adjustment for misclassification reduced women's odds ratios from 2.18 to 1.00 for hospital treatment and from 1.70 to 1.10 for antidepressants. For the lower social group, the corresponding odds ratios increased from 1.18 to 3.52, and from 1.35 to 2.32 respectively, whereas odds ratios with respect to age remained almost unchanged.

CONCLUSION

Differential misclassification should be considered when register-based information about hospital and antidepressant treatment are used as depression indicators.

Design paper: The CapOpus trial: a randomized, parallel-group, observer-blinded clinical trial of specialized addiction treatment versus treatment as usual for young patients with cannabis abuse and psychosis

Background

A number of studies indicate a link between cannabis-use and psychosis as well as more severe psychosis in those with existing psychotic disorders. There is currently insufficient evidence to decide the optimal way to treat cannabis abuse among patients with psychosis.

Objectives

The major objective for the CapOpus trial is to evaluate the additional effect on cannabis abuse of a specialized addiction treatment program adding group treatment and motivational interviewing to treatment as usual.

Design

The trial is designed as a randomized, parallel-group, observer-blinded clinical trial. Patients are primarily recruited through early-psychosis detection teams, community mental health centers, and assertive community treatment teams. Patients are randomized to one of two treatment arms, both lasting six months: 1) specialized addiction treatment plus treatment as usual or 2) treatment as usual. The specialized addiction treatment is manualized and consists of both individual and group-based motivational interviewing and cognitive behavioral therapy, and incorporates both the family and the case manager of the patient.

The primary outcome measure will be changes in amount of cannabis consumption over time. Other outcome measures will be psychosis symptoms, cognitive functioning, quality of life, social functioning, and cost-benefit analyses.

Trial registration

ClinicalTrials.gov NCT00484302.

Self-report of family functioning and risk for psychotic disorders in male adolescents with behavioural disturbances

OBJECTIVE

Previous studies indicate that a poor family environment might affect vulnerability for the later manifestation of psychotic illness. The current study aims to examine family functioning prior to the onset of psychosis.

METHOD

Subjects were 42,948, 17-year old males with behavioural disturbances who were asked about the functioning of their family by the Israeli Draft Board. Data on later psychiatric hospitalizations were obtained from a National Psychiatric Hospitalization Registry.

RESULTS

Poorer self-reported family functioning was associated with greater risk for later hospitalization for psychosis [adjusted hazard ratio (HR) = 1.16, 95% CI = 1.05-1.27], with a trend in the same direction for schizophrenia (adjusted HR = 1.1, 95% CI = 0.98-1.24).

CONCLUSION

In male adolescents with behavioural disturbances, perceived poorer family functioning is associated with increased risk for non-affective psychotic disorders and schizophrenia. These data do not enable us to determine if perceived familial dysfunction increases vulnerability for psychosis, if premorbid behavioural abnormalities disrupt family life, or neither.

Complaints of stress in young soldiers strongly predispose to psychiatric morbidity and mortality: Danish national cohort study with 10-year follow-up

OBJECTIVE

Serving military can be regarded as exposure to a moderate enforced stressor independent of other vulnerability factors. The aims of this study were i) to explore psychiatric morbidity and mortality during 10 years of follow-up in a cohort of healthy adolescent Danish conscripts and ii) to investigate whether stress-related disorders precede other psychiatric disorders.

METHOD

Controlled national cohort study on all psychiatric hospital contacts in young men referred to the Military Psychiatric Department (MPD) with 10 years of follow-up.

RESULTS

During the follow-up period, 24% of conscripts seen at the MPD were diagnosed with a psychiatric disorder compared with 4% in the control cohort. Almost all diagnostic categories were over-represented but especially psychotic disorders. Mortality was substantially increased. Of subjects initially diagnosed with stress-related disorders at the MPD, 20% later on developed psychopathology.

CONCLUSION

Young healthy men complaining of mental distress following a stressor are strongly disposed to psychiatric morbidity and mortality. The study suggests that stress-related disorders often precede more severe psychopathology.

Diagnostic stability among chronic patients with functional psychoses: an epidemiological and clinical study

BACKGROUND

Diagnostic stability and illness course of chronic non-organic psychoses are complex phenomena and only few risk factors or predictors are known that can be used reliably. This study investigates the diagnostic stability during the entire course of illness in patients with non-organic psychoses and attempts to identify non-psychopathological risk factors or predictors.

METHOD

100 patients with functional psychosis were initially characterised using the Operational Criteria Checklist for Psychotic Illness and Affective Illness (OPCRIT), medical records and health registers. To study the stability of diagnoses (i.e. shifts per time), we used registry data to define four measures of diagnostic variation that were subsequently examined in relation to four possible measures of time (i.e. observation periods or hospitalisation events). Afterwards, we identified putative co-variables and predictors of the best measures of diagnostic stability.

RESULTS

All four measures of diagnostic variation are very strongly associated with numbers-of-hospitalisations and less so with duration-of-illness, duration-of-hospitalisation and with year-of-first-admission. The four measures of diagnostic variation corrected for numbers-of-hospitalisations were therefore used to study the diagnostic stability. Conventional predictors of illness course - e.g. age-of-onset and premorbid-functioning - are not significantly associated with stability. Only somatic-comorbidity is significantly associated with two measures of stability, while family-history-of-psychiatric-illness and global-assessment-of-functioning (GAF) scale score show a trend. However, the traditional variables age-of-first-admission, civil-status, first-diagnosis-being-schizophrenia and somatic-comorbidity are able to explain two-fifth of the variation in numbers-of-hospitalisations.

CONCLUSION

Diagnostic stability is closely linked with the contact between patient and the healthcare system. This could very likely be due to fluctuation of disease manifestation over time or presence of co-morbid psychiatric illness in combination with rigid diagnostic criteria that are unable to capture the multiple psychopathologies of the functional psychoses that results in differential diagnoses and therefore diagnostic instability. Not surprisingly, somatic-comorbidity was found to be a predictor of diagnostic variation thereby being a non-psychiatric confounder.

Perinatal risk factors and infantile autism

OBJECTIVE

Suboptimal conditions during pregnancy and birth have been suggested as a cause of infantile autism. We have studied the association between obstetric factors and infantile autism.

METHOD

A population-based, matched case-control study of infantile autism. Conditional logistic regression was used to calculate odds ratios (OR) and 95% confidence intervals (CI).

RESULTS

The risk of infantile autism was increased for mothers aged >35 years, with foreign citizenship, and mothers who used medicine during pregnancy. A higher risk of infantile autism was seen among children with low birth weight and with congenital malformations. Birth interventions, pathological cardiotocography, green amnion fluid and acidosis during delivery were not associated with increased risk for infantile autism.

CONCLUSION

Our findings suggest that suboptimal birth conditions are not an independent risk factor for infantile autism. A high prevalence of low birth weight and birth defects among autism cases seems to explain the suboptimal birth outcome.

Cigarette smoking during pregnancy and hyperactive-distractible preschooler's: a follow-up study

AIM

To study the association between intrauterine exposure to tobacco smoke and behavioural disorders in preschool children, primarily symptoms of inattention, hyperactivity and impulsivity but also hostile-aggressive and anxious-fearful symptoms.

METHODS

We conducted a follow-up study in 1355 singletons born to Danish-speaking mothers. Information on smoking habits during pregnancy and other lifestyle factors was obtained from self-administered questionnaires filled in during second and third trimester. Approximately 3.5 years later, the parents provided information on their child's behaviour using the self-administered Preschool Behaviour Questionnaire. The children were categorized into three not mutually exclusive behaviour groups: hyperactive - distractible (13.6%), hostile-aggressive (4.6%), and anxious-fearful (6.4%) children.

RESULTS

Compared with children of non-smokers, children born to women who smoked 10 or more cigarettes per day had a 60% increased risk of hyperactivity and distractibility perceived by the parents (OR 1.6; 95% CI 1.0-2.3; P < 0.05). The results were adjusted for maternal lifestyle factors and socioeconomic characteristics. Additional adjustment for perinatal factors and parental psychiatric hospitalization did not change the results substantially (OR 1.7; 95% CI 1.1-2.6). We found no statistically significant association between maternal smoking in pregnancy and hostile-aggressive and anxious-fearful behaviour in the offspring.

CONCLUSION

Exposure to tobacco smoke in utero was associated with hyperactive-distractible behaviour in preschool children.

Premorbid intellectual functioning and risk of schizophrenia and spectrum disorders

Evidence from longitudinal studies indicates that lower IQ score in childhood and early adolescence increases risk of schizophrenia and schizophrenia spectrum disorders (SSD). This study investigated the association between premorbid IQ and risk of SSD in a population-based cohort of 17-year-old conscripts. Fifty four thousand males assessed by the Israeli Draft Board during two consecutive years were followed by means of the Israeli National Psychiatric Hospitalization Case Registry for up to 11 years. Tests of verbal and non-verbal reasoning, mathematical knowledge and instructions comprehension and several psychosocial variables were recorded by the Draft Board. Risk for SSD increased with decreasing IQ score. Only poorer non-verbal reasoning conferred a significant increased risk for SSD after taking into account general intellectual ability. IQ was not associated with age of onset. These results confirm the importance of low intellectual functioning as a risk factor for SSD. This is unlikely to be due to prodrome.

Sensitivity of ICD-10 diagnosis of psychotic disorders in the Israeli National Hospitalization Registry compared with RDC diagnoses based on SADS-L

OBJECTIVE

The Israeli National Psychiatric Hospitalization Registry is a nationwide list of all psychiatric hospitalizations in the country and has been widely used as a source of data for psychiatric research. This study assessed the sensitivity of the diagnosis of psychotic disorders ( International Statistical Classification of Diseases, 10th Revision [ ICD-10 ] F20.0-F29.9) and schizophrenia ( ICD-10 F20.0-F20.9) in the Registry.

METHOD

Registry discharge diagnoses of psychotic disorders ( ICD-10 F20.0-F29.9) and schizophrenia ( ICD-10 F20.0-F20.9) were compared with research diagnoses derived from best-estimate procedures based on Research Diagnostic Criteria (RDC) using structured clinical research interviews, hospital records, and family information.

RESULTS

Out of 169 patients meeting RDC for psychotic disorder, 150 also had a diagnosis of psychotic disorders in the Registry, yielding a sensitivity of 0.89. Re-running this analysis for the narrow definition of schizophrenia identified 94 patients who were diagnosed with schizophrenia using RDC; 82 of those patients also had a diagnosis of schizophrenia in the Registry, yielding a sensitivity of 0.87.

CONCLUSION

In 87% to 89% of cases with psychotic disorders or with schizophrenia, Registry diagnoses agreed with RDC diagnoses, a rate of agreement comparable with those of other, similar registries. Because a large number of analyses derived from this and similar national registries will be published in the coming years, this constitutes relevant information.

Mental health in prison populations. A review--with special emphasis on a study of Danish prisoners on remand

OBJECTIVE

To review the literature on mental health and psychiatric morbidity in prison populations and relate findings to a Danish study on remand prisoners.

METHOD

The literature is reviewed and subdivided in the following section: validity of psychometrics in prison populations, prevalence of psychiatric disorders prior to imprisonment, incidence of psychiatric disorders during imprisonment, psychopathy related to psychiatric comorbidity, dependence syndromes with special emphasis on different administrations of heroin use (smoke vs. injection). The results are compared with a longitudinal Danish study on remand prisoners in either solitary confinement (SC) or non-SC.

RESULTS

Many factors must be taken into consideration when dealing with prisoners and mental health, e.g. international differences, the prison setting, demographics and methodological issues. The prison populations in general are increasing worldwide. Psychometrics may perform differently in prison populations compared with general populations with the General Health Questionnaire-28 having a low validity in remand prisoners. Psychiatric morbidity including schizophrenia is higher and perhaps increasing in prison populations compared with general populations with dependence syndromes being the most frequent disorders. The early phase of imprisonment is a vulnerable period with a moderately high incidence of adjustment disorders and twice the incidence in SC compared with non-SC. Prevalence of psychopathy is lower in European than North American prisons. Medium to high scores of psychopathy is related to higher psychiatric comorbidity. Opioid dependence is the most frequent drug disorder with subjects using injection representing a more dysfunctional group than subjects using smoke administration. Many mentally ill prisoners remain undetected and undertreated.

CONCLUSION

There is a growing population of mentally ill prisoners being insufficiently detected and treated.

The goals and method of the Andalusian Case Register for Schizophrenia

BACKGROUND

Psychiatric case registers have been acknowledged as a valuable source of data, a long time ago. However, a growing interest exists in data on service utilization by patients belonging to groups with a related diagnosis to enable adequate planning of health resources.

AIMS

The aims of the Andalusian Case Register for Schizophrenia are to determine the prevalence of schizophrenia of those cared for by the public network of mental health services and to describe their pattern of care.

METHODS

Cases included on the Register are those persons resident in South Granada area with a diagnosis of schizophrenia and related disorders. The agencies which sent the information to the Register are all the mental health facilities in the catchment area.

CONCLUSIONS

The Register is a flexible instrument to use for epidemiological research and mental health care planning.

Mortality in concurrent type 1 diabetes and anorexia nervosa

OBJECTIVE

Previous studies in this field report early occurrence of diabetic complications, but excess mortality, though expectable, has not been reported. We combined information from earlier studies to estimate the mortality for this group of patients.

RESEARCH DESIGN AND METHODS

The observed mortality is analyzed using crude mortality rate (a percentage), standardized mortality ratio (SMR), incidence rate ratio, risk difference, and survival analysis.

RESULTS

After approximately 10 years of follow-up, 13 of 510 females with type 1 diabetes, 43 of 658 females with anorexia nervosa (AN), and 8 of 23 concurrent case subjects had died. Mortality rate was 2.2 (per 1,000 person-years) for type 1 diabetes, 7.3 for AN cases, and 34.6 for concurrent cases. Crude mortality rates were 2.5, 6.5, and 34.8%, respectively. SMR was 4.06 in type 1 diabetes, 8.86 in AN, and 14.5 in concurrent cases. Survival analysis indicated between-group differences in mortality.

CONCLUSIONS

Concurrent type 1 diabetes and AN is a rare but serious condition in females. All indexes of mortality evidence excess mortality in this preliminary study. Vigorous and well-directed treatment efforts seem vital for this subpopulation. Collaboration between diabetologists and eating disorder specialists is warranted. The implications of other eating disorders and subclinical eating disorders in diabetic populations need to be analyzed, especially because these conditions are more frequent than clinical eating disorders.

Obstetric factors, urbanization and psychosis

BACKGROUND

Epidemiologic evidence as early as the 1930s has suggested urbanization is linked to schizophrenia, either by place of admission, place of upbringing, or, more recently, place of birth. In the past decade, obstetric complications have been implicated in the etiology of schizophrenia.

METHODS

With appropriate protections for anonymity, the files of the Danish Medical Birth Register were linked with the files of the Danish Psychiatric Case Register. The linkage produced 132 cases of schizophrenia and 69 cases of affective psychosis, who were born in 1973 or later, who entered a Danish psychiatric hospital before 1994. Controls were drawn from a 10% sample of the Medical Birth Register. Analysis was by logistic regression.

RESULTS

The risk of hospitalization for schizophrenia was 4.20 times higher (95% CI=2.4-7.4) for those born in Copenhagen versus those born in rural areas of Denmark, and a linear relationship was demonstrated between urbanization of birthplace and risk. There was no difference in risk of hospitalization for affective psychosis for those born in Copenhagen versus rural areas. Obstetric complications had a moderate sized relationship to schizophrenia, but the relationship of urban birth to schizophrenia was unaffected by adjustment for obstetric complications.

CONCLUSION

Urban birth is a strong risk factor for schizophrenia, not mediated by obstetric complications, which deserves further exploration.

Affective disorders among Greenlandic psychiatric patients

OBJECTIVE

The aim of this study was to determine the treatment incidence, diagnostic stability and clinical and social outcome of affective disorders in the Greenlandic population.

METHODS

A cohort of Greenlanders first hospitalized in 1980-1983 and diagnosed with an affective disorder at least once during the period 7 to 12 years after first admission formed the study population. The manic-depressive patients who were still alive at follow-up were invited for a Present State Examination, and information about clinical and social condition was obtained for the total cohort.

RESULTS

The rates of manic-depressive psychoses diagnosed at first admission or later were 6.6 for men and 20.4 for women per 100,000 individuals of over 15 years of age. The unipolar:bipolar ratio was very low, namely 1:3 for men and 1:2 for women. Outcome was relatively poor.

CONCLUSION

Manic-depression is a recognizable diagnostic category in Greenland. Extremely low rates of unipolar disorders in both sexes and high rates of bipolar disorders among women were the most marked findings.

The effect of the first manic episode in affective disorder: a case register study of hospitalised episodes

BACKGROUND

It is poorly understood how the course of illness in depressive patients is affected by a manic episode.

METHOD

The course of hospitalised episodes was compared for patients with depressive episodes only, patients who presented with a manic or circular first episode and patients who presented with a depressive first episode and later developed mania. The Danish psychiatric central register was used as a study base, including all hospital admissions with primary affective disorder in Denmark during 1971-1993.

RESULTS

A total of 17,447 patients presented with a depressive first episode and 2903 patients with a manic or circular first episode. Among the 17,447 depressive patients, 762 patients presented with mania at later episodes (4.4%). Younger age at onset was associated with increased risk of developing mania. Patients who had a late first manic episode had the same rate of subsequent recurrence as patients with mania at first episode and this rate was higher than the rate of recurrence for patients who remained having depressive episodes only. Time since first manic episode was without importance in relation to the risk of subsequent recurrence.

CONCLUSION

Patients who present with depression and later develop mania have from onset the same risk of recurrence as initially bipolar patients.

LIMITATION

The data relate to admissions rather than episodes.

CLINICAL RELEVANCE

Younger patients who present with depression have increased risk of developing bipolar disorder.

Psychopathy and psychopathological profiles in prisoners on remand

A total of 178 Danish male remand prisoners were examined using comprehensive interviews and questionnaires on psychopathological, personality and social measures, and file data. These data were compared with scores on the Hare Psychopathy Checklist - Revised (PCL-R). Subjects were divided into four groups according to quartile PCL-R scores. In general there were high rates of psychiatric morbidity in all PCL-R quartile groups. The medium-high scorers represent a more vulnerable group with a high prevalence of dependence disorders, relatively high neuroticism score and relatively high prevalence of neurotic and stress-related disorders. The high scorers were more psychosocially maladjusted, had more often made previous suicidal attempts, and had a higher psychoticism score. Chronic psychotic disorders did occur, mostly in the high-scoring group. The population had lower scores on the PCL-R than in most previous studies, suggesting a lower prevalence of psychopathic features among Danish criminals and possibly a lower cut-off point when using the PCL-R as a categorical measure. Both findings are consistent with the results of other European studies. Further studies on cross-cultural differences with regard to PCL-R psychopathic features and on psychic vulnerability related to PCL-R scores and factor 1/factor 2 of the PCL-R are suggested.

Standardized mortality in eating disorders--a quantitative summary of previously published and new evidence

Ten eating disorder (ED) populations were reviewed using the standardized mortality ratio (SMR) presenting new evidence for several studies. In eight of the ten samples, strong evidence (in one sample weak evidence and in one sample no evidence) supports an hypothesis of elevated SMR. We found strong evidence for an increase in SMR for anorexia nervosa (AN), whereas no firm conclusions could be drawn for bulimia nervosa (BN). Bias caused by loss to follow-up was quantified and found non-negligable in some samples (possible increase in SMR from 25% to 240%). We did not find a significant effect of gender or time period on SMR. Survival analysis showed a significant difference among the life-tables for males and females; female risk of death averaged 0.59% per year, whereas all male deaths occurred within the first 2 years after presentation. Weight at presentation had a highly significant effect on SMR, and lower weight at presentation was associated with higher SMR. Age at presentation exerted a significant unimodal effect on SMR; aggregate overall SMR was 3.6 for the youngest age group (< 20 years), 9.9 for those aged 20-29 years, and 5.7 for those aged > or = 30 years at presentation. Length of follow-up had a highly significant inverse effect on SMR; maximal SMR was 30 for female AN patients in the first year after presentation. A statistically significant increase in SMR was documented for at least up to 15 years after presentation. One study indicated a treatment effect on SMR. New evidence on causes of death suggests there are more deaths from suicide and other and unknown causes and fewer deaths related to ED than previously reported. Our findings have both research and clinical implications, with the most important clinical implication being the need for vigorous and well-directed treatment efforts from the initial presentation for treatment. An important research implication is that no single measure of mortality is sufficient; that is, only a combination of different statistics will maximize the available information.

Recurrence in affective disorder. II. Effect of age and gender

BACKGROUND

The risk of recurrence in affective disorder has been found to increase with each new episode. It is unclear whether it is universal without regard to gender, age and type of disorder.

METHOD

Survival analysis was used to estimate the risk of recurrence in a case-register study including all hospital admissions with primary affective disorder in Denmark from 1971-1993. In this period 20,350 first-admission patients had been discharged with a diagnosis of affective disorder, depressive or manic/cyclic type.

RESULTS

The risk of recurrence increased with the number of previous episodes regardless of the combination of gender, age and type of disorder. Initially in the course of illness, unipolar and bipolar women experienced an equal greater risk of recurrence than men. The risk of recurrence after the first episode was increased for middle-aged and older unipolar women compared with the risk for younger women, while after all other episodes younger age at first episode increased the risk of recurrence.

CONCLUSIONS

The course of severe unipolar and bipolar disorder seems to be progressive in nature irrespective of gender, age and type of disorder.