Discontinuation of psychotropic medication: a synthesis of evidence across medication classes

Pharmacotherapy is an effective treatment modality across psychiatric disorders. Nevertheless, many patients discontinue their medication at some point. Evidence-based guidance for patients, clinicians, and policymakers on rational discontinuation strategies is vital to enable the best, personalized treatment for any given patient. Nonetheless, there is a scarcity of guidelines on discontinuation strategies. In this perspective, we therefore summarize and critically appraise the evidence on discontinuation of six major psychotropic medication classes: antidepressants, antipsychotics, benzodiazepines, mood stabilizers, opioids, and stimulants. For each medication class, a wide range of topics pertaining to each of the following questions are discussed: (1) Who can discontinue (e.g., what are risk factors for relapse?); (2) When to discontinue (e.g., after 1 year or several years of antidepressant use?); and (3) How to discontinue (e.g., what's the efficacy of dose reduction compared to full cessation and interventions to mitigate relapse risk?). We thus highlight how comparing the evidence across medication classes can identify knowledge gaps, which may pave the way for more integrated research on discontinuation.

Unhealthy lifestyle impacts on biological systems involved in stress response: hypothalamic-pituitary-adrenal axis, inflammation and autonomous nervous system

An unhealthy lifestyle has a critical role in the pathogenesis and course of several chronic disorders. It has been hypothesized that lifestyle may also impact biological systems involved in stress response. A global index of unhealthy lifestyle was calculated based on the cumulative presence of five self-reported lifestyle habits (smoking, excessive alcohol use, drug use, low physical activity and short sleep) in 2783 participants (18-65 years) from the Netherlands Study of Depression and Anxiety. The functioning of biological stress systems was based on multiple physiological measures of cortisol, inflammatory cytokines and autonomic cardiac activity. The unhealthy lifestyle index was associated with hyperactivity of hypothalamus-pituitary-adrenal axis and increased inflammation, indicating that with increasing unhealthy habits, the level of biological stress increases. No association with the autonomic nervous system activity was observed; however, the use of drugs increased parasympathetic cardiac activity and significantly impacted on ANS. Results were not impacted by a recent episode of depression or anxiety disorder. An unhealthy lifestyle may unfavorably impact on biological systems involved in stress response, which may underlie progression of several psychiatric as well as somatic chronic disorders.

Oral contraceptives, depressive and insomnia symptoms in adult women with and without depression

BACKGROUND

Worldwide, oral contraceptive (OC) use is a very common form of birth control, although it has been associated with symptoms of depression and insomnia. Insomnia is a risk factor for major depressive disorder (MDD) but may also be a symptom of the disorder. Despite the large number of women who use OC, it is yet unknown whether women with previous or current diagnosis of depression are more likely to experience more severe depressive and insomnia symptoms during concurrent OC use than women without diagnosis of depression.

AIM

This study examined associations between OC use and concurrent symptoms of depression (including atypical depression) and insomnia as well as between OC and prevalences of concurrent dysthymia and MDD. Participants were adult women with and without a history of MDD or dysthymia. We hypothesized that OC use is associated with concurrent increased severity of depressive symptoms and insomnia symptoms, as well as with an increased prevalence of concurrent diagnoses of dysthymia and MDD. We also hypothesized that a history of MDD or dysthymia moderates the relationship between OC use and depressive and insomnia symptoms.

METHODS

Measurements from premenopausal adult women from the Netherlands Study of Depression and Anxiety (NESDA) were grouped, based on whether participants were using OC or naturally cycling (NC). OC use, timing and regularity of the menstrual cycle were assessed with a structured interview, self-reported symptoms of depression (including atypical depression), insomnia with validated questionnaires, and MDD and dysthymia with structured diagnostic interviews.

RESULTS

We included a total of 1301 measurements in women who reported OC use and 1913 measurements in NC women (mean age 35.6, 49.8% and 28.9% of measurements in women with a previous depression or current depression, respectively). Linear mixed models showed that overall, OC use was neither associated with more severe depressive symptoms (including atypical depressive symptoms), nor with higher prevalence of diagnoses of MDD or dysthymia. However, by disentangling the amalgamated overall effect, within-person estimates indicated increased depressive symptoms and depressive disorder prevalence during OC use, whereas between-person estimated indicated lower depressive symptoms and prevalence of depressive disorders. OC use was consistently associated with more severe concurrent insomnia symptoms, in the overall estimates as well as in the within-person and between-person estimates. Presence of current or previous MDD or dysthymia did not moderate the associations between OC use and depressive or insomnia symptoms.

DISCUSSION

The study findings showed consistent associations between OC use and more severe insomnia symptoms, but no consistent associations between OC and depressive symptoms or diagnoses. Instead, post-hoc analyses showed that associations between OC and depression differed between within- and between person-estimates. This indicates that, although OC shows no associations on the overall level, some individuals might experience OC-associated mood symptoms. Our findings underscore the importance of accounting for individual differences in experiences during OC use. Furthermore, it raises new questions about mechanisms underlying associations between OC, depression and insomnia.

Emotional processing in panic disorder and its subtypes: An fMRI study using emotional faces

BACKGROUND

Inconsistent findings regarding the pathophysiology of panic disorder (PD) could result from clinical heterogeneity. Identifying subtypes could enhance insights into the neurobiological substrates of PD.

METHODS

An emotional faces fMRI paradigm was used in a group of PD patients (n = 73) and healthy controls (n = 58). The overall PD group was further divided into three previously identified subtypes: a cognitive-autonomic (n = 22), an autonomic (n = 16) and an aspecific (n = 35) subtype. Differences in brain activity levels in response to emotional facial expressions between groups were examined for six regions of interests, namely the amygdala, ventromedial prefrontal cortex, anterior cingulate, fusiform gyrus, lingual gyrus and insula.

RESULTS

PD patients showed lower activity in the rostral anterior cingulate in response to angry faces than healthy controls, which was mainly driven by the autonomic subtype. No significant differences were found in other brain regions when comparing PD patients with controls or when comparing across PD subtypes.

LIMITATIONS

Sample sizes in subgroups were relatively small CONCLUSIONS: The role of the rostral anterior cingulate cortex for emotional processes critical in panic disorder is highlighted by this study and provides, albeit preliminary, evidence for the use of a subtype approach to advance our neurobiological insights in PD considering its involvement in the appraisal of autonomic viscero-sensory symptoms.

The correlates of social phobia in OCD: Findings from a large clinical sample

OBJECTIVES

Obsessive-compulsive disorder (OCD) is a debilitating psychiatric disorder, often complicated with comorbidities. Social phobia (SP) is the most frequent co-occurring anxiety disorder in OCD, associated with increased clinical severity. However, no study had examined the relevance of interpersonal processes in this comorbidity, which are at the core of SP. This study characterized the clinical (i.e., symptom profile, age of onset, chronicity, and comorbidity), vulnerability (i.e., childhood trauma, negative life events), and interpersonal (attachment style, expressed emotion, and social support) correlates of comorbid SP in a large sample of OCD patients.

METHODS

We analysed the data of 382 OCD patients participating in the Netherlands Obsessive Compulsive Disorder Association (NOCDA) study. We examined the correlates of SP in OCD using self-report questionnaires and structured clinical interviews. In addition, data of 312 non-OCD SP patients were drawn from the Netherlands Study of Depression and Anxiety (NESDA), to compare the age of onset of SP between groups. Descriptive univariate analyses were followed by backward stepwise logistic regression analyses.

RESULTS

Social phobia was present among approximately 20% of OCD patients. Social phobia in OCD was associated with increased depression severity and decreased ratings of secure attachment style. Among OCD patients, SP had a significantly earlier age onset as compared to SP in non-OCD patients.

CONCLUSION

Social phobia in OCD might render a vulnerable clinical picture, characterized with early onset of SP symptoms, insecure attachment style, and increased depressive symptoms. Future studies should use prospective designs to better understand the nature of comorbid SP in OCD.

PRACTITIONER POINTS

Approximately one fifth of OCD patients were diagnosed with comorbid social phobia in a large representative clinical sample. OCD patients with comorbid social phobia presented with a vulnerable clinical picture, characterized with increased depression severity and decreased ratings of secure attachment style. Social phobia in OCD was associated with an earlier AOO as compared to the AOO of social phobia without OCD. The findings are limited by a cross-sectional design; thus, causality could not be assessed. Research is needed to further examine the mechanisms of comorbid social phobia in OCD.

Sex-dimorphic genetic effects and novel loci for fasting glucose and insulin variability

Differences between sexes contribute to variation in the levels of fasting glucose and insulin. Epidemiological studies established a higher prevalence of impaired fasting glucose in men and impaired glucose tolerance in women, however, the genetic component underlying this phenomenon is not established. We assess sex-dimorphic (73,089/50,404 women and 67,506/47,806 men) and sex-combined (151,188/105,056 individuals) fasting glucose/fasting insulin genetic effects via genome-wide association study meta-analyses in individuals of European descent without diabetes. Here we report sex dimorphism in allelic effects on fasting insulin at IRS1 and ZNF12 loci, the latter showing higher RNA expression in whole blood in women compared to men. We also observe sex-homogeneous effects on fasting glucose at seven novel loci. Fasting insulin in women shows stronger genetic correlations than in men with waist-to-hip ratio and anorexia nervosa. Furthermore, waist-to-hip ratio is causally related to insulin resistance in women, but not in men. These results position dissection of metabolic and glycemic health sex dimorphism as a steppingstone for understanding differences in genetic effects between women and men in related phenotypes.

Delayed sleep-onset and biological age: late sleep-onset is associated with shorter telomere length

STUDY OBJECTIVES

We evaluated the relationship between leukocyte telomere length (LTL) and sleep duration, insomnia symptoms, and circadian rhythm, to test whether sleep and chronobiological dysregulations are associated with cellular aging.

METHODS

Data from the Netherlands Study of Depression and Anxiety (N = 2,936) were used at two waves 6 years apart, to measure LTL. Telomeres shorten during the life span and are important biomarkers for cellular aging. LTL was assessed by qualitative polymerase chain reaction and converted into base pair number. Sleep parameters were: sleep duration and insomnia symptoms from the Insomnia Rating Scale. Circadian rhythm variables were: indication of Delayed Sleep Phase Syndrome (DSPS), mid-sleep corrected for sleep debt on free days (MSFsc), sleep-onset time, and self-reported chronotype, from the Munich Chronotype Questionnaire. Generalized estimating equations analyzed the associations between LTL, sleep, and chronobiological factors, adjusted for baseline age, sex, North European ancestry, and additionally for current smoking, depression severity, obesity, and childhood trauma.

RESULTS

Indicators of delayed circadian rhythm showed a strong and consistent effect on LTL, after adjustment for sociodemographic and health indicators. Late MSFsc (B = -49.9, p = .004), late sleep-onset time (B = -32.4, p = .001), indication of DSPS (B = -73.8, p = .036), and moderately late chronotype in adulthood (B = -71.6, p = .003) were associated with significantly shorter LTL across both waves; whereas sleep duration and insomnia symptoms were not. Extremely early chronotype showed significantly less LTL shortening than intermediate chronotype (B = 161.40, p = .037). No predictors showed accelerated LTL attrition over 6 years.

CONCLUSIONS

Individuals with delayed circadian rhythm have significantly shorter LTL, but not faster LTL attrition rates.

Neuroticism and chronicity as predictors of 9-year course of individual depressive symptoms

BACKGROUND

The large between-person differences in symptomatology suggest that major depressive disorder (MDD) is a heterogeneous psychiatric disorder. However, symptom-specific prospective studies are scarce. We hypothesized that chronicity (i.e., being depressed for 24 months during a patient's preceding 48 months at baseline) and neuroticism at baseline would predict adverse course trajectories over 9 years of follow up with differential magnitudes for individual depressive symptoms.

METHODS

In total, 560 patients with a current MDD were included from the Netherlands Study of Depression and Anxiety (NESDA-cohort). We used a multivariate linear mixed model with repeated measures, with a history of chronicity and neuroticism separately as main independent variables and with Inventory of Depressive Symptomatology self-report (IDS-SR) item scores as outcome variables. For each individual symptom, the model was adjusted for age, gender, and baseline depression severity.

RESULTS

Patients were on average 42.7 (SD = 12.1) years old and 64.7% were women. Patients with chronic depression or high levels of neuroticism showed similar absolute rates of decline over time compared to their counterparts. However, because symptoms had higher starting points for mood, cognitive, and somatic/vegetative symptoms (in that order), symptom severity remained higher over time. Chronicity and neuroticism were especially linked to persistent low self-esteem and high interpersonal sensitivity.

LIMITATIONS

Neuroticism is partly state dependent and likely affected by depression severity.

CONCLUSIONS

Chronicity and neuroticism predict long-term persistence of diverse psychiatric symptoms, in particular low self-esteem and high interpersonal sensitivity.

Repetitive negative thinking as a mediator in prospective cross-disorder associations between anxiety and depression disorders and their symptoms

BACKGROUND AND OBJECTIVES

Comorbidity among anxiety and depression disorders and their symptoms is high. Rumination and worry have been found to mediate prospective cross-disorder relations between anxiety and depression disorders and their symptoms in adolescents and adults. We examined whether generic repetitive negative thinking (RNT), that is content- and disorder-independent, also mediates prospective cross-disorder associations between anxiety and depressions disorders and their symptoms.

METHODS

This was studied using a 5-year prospective cohort study. In a mixed sample of 1859 adults (persons with a prior history of or a current affective disorder and healthy individuals), we assessed DSM-IV affective disorders (Composite Interview Diagnostic Instrument), anxiety (Beck Anxiety Inventory) and depression symptoms (Inventory of Depressive Symptomatology) and RNT (Perseverative Thinking Questionnaire).

RESULTS

We found that baseline depression disorders and symptom severity have predictive value for anxiety disorders and symptom severity five years later (and vice versa) and that these associations were significantly mediated by level of RNT as assessed two years after baseline. The significant and rather large mediation effects seemed mainly due to the mental capacity captured by RNT, especially in the prospective relation of anxiety with future depression.

LIMITATIONS

The mediation effects were greatly attenuated or even nullified after rigorously controlling for concomitant psychopathology at two years after baseline.

CONCLUSIONS

From these results it can be concluded that repetitive negative thinking could be an important transdiagnostic factor, that may constitute a suitable target for treatment.

Large-scale plasma metabolome analysis reveals alterations in HDL metabolism in migraine

OBJECTIVE

To identify a plasma metabolomic biomarker signature for migraine.

METHODS

Plasma samples from 8 Dutch cohorts (n = 10,153: 2,800 migraine patients and 7,353 controls) were profiled on a ¹H-NMR-based metabolomics platform, to quantify 146 individual metabolites (e.g., lipids, fatty acids, and lipoproteins) and 79 metabolite ratios. Metabolite measures associated with migraine were obtained after single-metabolite logistic regression combined with a random-effects meta-analysis performed in a nonstratified and sex-stratified manner. Next, a global test analysis was performed to identify sets of related metabolites associated with migraine. The Holm procedure was applied to control the family-wise error rate at 5% in single-metabolite and global test analyses.

RESULTS

Decreases in the level of apolipoprotein A1 (β -0.10; 95% confidence interval [CI] -0.16, -0.05; adjusted p = 0.029) and free cholesterol to total lipid ratio present in small high-density lipoprotein subspecies (HDL) (β -0.10; 95% CI -0.15, -0.05; adjusted p = 0.029) were associated with migraine status. In addition, only in male participants, a decreased level of omega-3 fatty acids (β -0.24; 95% CI -0.36, -0.12; adjusted p = 0.033) was associated with migraine. Global test analysis further supported that HDL traits (but not other lipoproteins) were associated with migraine status.

CONCLUSIONS

Metabolic profiling of plasma yielded alterations in HDL metabolism in migraine patients and decreased omega-3 fatty acids only in male migraineurs.

GWAS and colocalization analyses implicate carotid intima-media thickness and carotid plaque loci in cardiovascular outcomes

Carotid artery intima media thickness (cIMT) and carotid plaque are measures of subclinical atherosclerosis associated with ischemic stroke and coronary heart disease (CHD). Here, we undertake meta-analyses of genome-wide association studies (GWAS) in 71,128 individuals for cIMT, and 48,434 individuals for carotid plaque traits. We identify eight novel susceptibility loci for cIMT, one independent association at the previously-identified PINX1 locus, and one novel locus for carotid plaque. Colocalization analysis with nearby vascular expression quantitative loci (cis-eQTLs) derived from arterial wall and metabolic tissues obtained from patients with CHD identifies candidate genes at two potentially additional loci, ADAMTS9 and LOXL4. LD score regression reveals significant genetic correlations between cIMT and plaque traits, and both cIMT and plaque with CHD, any stroke subtype and ischemic stroke. Our study provides insights into genes and tissue-specific regulatory mechanisms linking atherosclerosis both to its functional genomic origins and its clinical consequences in humans.

Repetitive negative thinking as a predictor of depression and anxiety: A longitudinal cohort study

BACKGROUND

Repetitive Negative Thinking (RNT) is assumed to be a transdiagnostic proximal risk factor in depression and anxiety. We examined the prospective relations of disorder-dependent as well as disorder-independent measures of RNT with depression and anxiety outcomes.

METHODS

In a prospective cohort study, 1972 adults completed a 3-year follow-up period (attrition = 12.6%). DSM-IV diagnoses were assessed with the CIDI, symptom severity with the IDS and BAI, and RNT with measures for perseverative thinking (PTQ), rumination (LEIDS-R) and worry (PWQ).

RESULTS

The common dimension of our RNT measurements (according to Confirmatory Factor Analysis) was significantly associated with comorbidity among depressive and among anxiety disorders, severity of depressive and anxiety symptoms, as well as persistence and relapse of depressive and anxiety disorders. Additionally, a specific factor for rumination predicted comorbidity of depressive disorders, comorbidity of anxiety disorders and relapse of depressive disorder, while a specific factor for worry predicted comorbidity of anxiety disorders and relapse of anxiety disorders, although to a lesser extent than general RNT.

LIMITATIONS

The present study relied solely on self-report measures of RNT and controlling for baseline demographic and clinical variables greatly attenuated the predictive value of RNT.

DISCUSSION

Disorder-independent RNT may be a similar underlying process present across depressive and anxiety disorders. It seems more important than the representation of this process in disorder-specific cognitive content such as rumination in depression and worry in anxiety. RNT as a pathological trait deserves more attention in clinical diagnosis and the transdiagnostic treatment of comorbid depression and anxiety in particular.

The Association Between Insomnia and Sleep Duration in Adults With Attention-Deficit Hyperactivity Disorder: Results From a General Population Study

STUDY OBJECTIVES

Insomnia and short or long sleep duration are important comorbid conditions in adults with attention-deficit hyperactivity disorder (ADHD), but reports of the association vary. In a general population study, we evaluated the relationship between ADHD symptom severity, insomnia symptoms, and sleep duration in adults.

METHODS

Data were from the third wave of the Netherlands Mental Health Survey and Incidence Study-2 (NEMESIS-2; n = 4,618). ADHD symptom severity and symptom dimensions (hyperactivity and inattention) were assessed using the Adult ADHD Self-Report Scale screener. Self-reported insomnia symptoms (Insomnia Rating Scale; IRS) were defined as clinically relevant if IRS ≥ 9. Self-reported short sleep duration was defined as ≤ 6 hours, and long sleep duration as ≥ 10 hours.

RESULTS

Within the group with clinically relevant ADHD symptoms, 43% reported significant insomnia symptoms (odds ratio [OR] = 2.66, 95% confidence interval [CI] 1.74-4.07); 41% short sleep duration (relative risk ratio [RRR] = 1.94, 95% CI 1.31-2.85) and 6% long sleep (RRR = 5.87, 95% CI 1.97-17.45). Increased inattention symptoms were associated with IRS ≥ 9, short and long sleep duration in fully adjusted models (OR = 1.10, 95% CI 1.06-1.14; RRR = 1.06, 95% CI 1.02-1.09; RRR = 1.16, 95% CI 1.05-1.28, respectively). Increased hyperactivity symptoms were associated with IRS ≥ 9 (OR = 1.17, 95% CI 1.11-1.23) and short sleep duration (RRR = 1.12, 95% CI 1.05-1.19).

CONCLUSIONS

Both clinically significant ADHD symptoms and inattention and hyperactivity symptom dimensions were consistently associated with insomnia symptoms and altered sleep duration. These associations confirm that sleep disturbances should be assessed and given appropriate clinical attention in adults with ADHD.

The reciprocal relationship between physical activity and depression: Does age matter?

BACKGROUND

The level of physical activity (PA) and the prevalence of depression both change across the lifespan. We examined whether the association between PA and depression is moderated by age. As sense of mastery and functional limitations have been previously associated with low PA and depression in older adults, we also examined whether these are determinants of the differential effect of age on PA and depression.

METHODS

1079 patients with major depressive disorder (aged 18-88 years) were followed-up after two-years; depression diagnosis and severity as well as PA were re-assessed. Linear and logistic regression analyses were used to test reciprocal prospective associations between PA and depression outcomes. In all models the interaction with age was tested.

RESULTS

PA at baseline predicted remission of depressive disorder at follow-up (OR = 1.43 [95% CI: 1.07-1.93], p = .018). This effect was not moderated by age. PA predicted improvement of depression symptom severity in younger (B = -2.03; SE = .88; p = .022), but not in older adults (B = 2.24; SE = 1.48; p = .128) (p = .015 for the interaction PA by age in the whole sample). The level of PA was relatively stable over time. Depression, sense of mastery and functional limitation were for all ages not associated with PA at follow-up.

CONCLUSIONS

Age did not moderate the impact of PA on depressive disorder remission. Only in younger adults, sufficient PA independently predicts improvement of depressive symptom severity after two-year follow-up. Level of PA rarely changed over time, and none of the determinants tested predicted change in PA, independent of age.

Presence and Predictive Value of Obsessive-Compulsive Symptoms in Anxiety and Depressive Disorders

OBJECTIVE

Obsessive-compulsive symptoms (OCS) co-occur frequently with anxiety and depressive disorders, but the nature of their relationship and their impact on severity of anxiety and depressive disorders is poorly understood. In a large sample of patients with anxiety and depressive disorders, we assessed the frequency of OCS, defined as a Young Adult Self-Report Scale-obsessive-compulsive symptoms score >7. The associations between OCS and severity of anxiety and/or depressive disorders were examined, and it was investigated whether OCS predict onset, relapse, and persistence of anxiety and depressive disorders.

METHODS

Data were obtained from the third (at 2-year follow-up) and fourth wave (at 4-year follow-up) of data collection in the Netherlands Study of Anxiety and Depression cohort, including 469 healthy controls, 909 participants with a remitted disorder, and 747 participants with a current anxiety and/or depressive disorder.

RESULTS

OCS were present in 23.6% of the total sample, most notably in those with current combined anxiety and depressive disorders. In patients with a current disorder, OCS were associated with severity of this disorder. Moreover, OCS predicted (1) first onset of anxiety and/or depressive disorders in healthy controls (odds ratio [OR], 5.79; 95% confidence interval [CI], 1.15 to 29.14), (2) relapse in those with remitted anxiety and/or depressive disorders (OR, 2.31; 95% CI, 1.55 to 3.46), and (3) persistence in patients with the combination of current anxiety and depressive disorders (OR, 4.42; 95% CI, 2.54 to 7.70) within the 2-year follow-up period Conclusions: OCS are closely related to both the presence and severity of anxiety and depressive disorders and affect their course trajectories. Hence, OCS might be regarded as a course specifier signaling unfavorable outcomes. This specifier may be useful in clinical care to adapt and intensify treatment in individual patients.

An Analysis of Two Genome-wide Association Meta-analyses Identifies a New Locus for Broad Depression Phenotype

BACKGROUND

The genetics of depression has been explored in genome-wide association studies that focused on either major depressive disorder or depressive symptoms with mostly negative findings. A broad depression phenotype including both phenotypes has not been tested previously using a genome-wide association approach. We aimed to identify genetic polymorphisms significantly associated with a broad phenotype from depressive symptoms to major depressive disorder.

METHODS

We analyzed two prior studies of 70,017 participants of European ancestry from general and clinical populations in the discovery stage. We performed a replication meta-analysis of 28,328 participants. Single nucleotide polymorphism (SNP)-based heritability and genetic correlations were calculated using linkage disequilibrium score regression. Discovery and replication analyses were performed using a p-value-based meta-analysis. Lifetime major depressive disorder and depressive symptom scores were used as the outcome measures.

RESULTS

The SNP-based heritability of major depressive disorder was 0.21 (SE = 0.02), the SNP-based heritability of depressive symptoms was 0.04 (SE = 0.01), and their genetic correlation was 1.001 (SE = 0.2). We found one genome-wide significant locus related to the broad depression phenotype (rs9825823, chromosome 3: 61,082,153, p = 8.2 × 10^-9) located in an intron of the FHIT gene. We replicated this SNP in independent samples (p = .02) and the overall meta-analysis of the discovery and replication cohorts (1.0 × 10^-9).

CONCLUSIONS

This large study identified a new locus for depression. Our results support a continuum between depressive symptoms and major depressive disorder. A phenotypically more inclusive approach may help to achieve the large sample sizes needed to detect susceptibility loci for depression.

Telomere length is inversely correlated with urinary stress hormone levels in healthy controls but not in un-medicated depressed individuals-preliminary findings

OBJECTIVE

Leukocyte telomere length (LTL) is a biomarker of cellular aging affected by chronic stress. The relationship of LTL to the stress hormones, cortisol and catecholamines, is unclear, as are possible differences between healthy controls (HC) and individuals with Major Depressive Disorder (MDD). This small pilot study is the first to examine the relationship between cortisol, catecholamines and LTL specifically in un-medicated MDD in comparison with HC.

METHODS

Participants included 16 un-medicated MDD subjects and 15 HC for assay of LTL, 12-hour overnight urinary free cortisol and catecholamine levels.

RESULTS

LTL, cortisol and catecholamine levels did not significantly differ between groups. In HC, a hierarchical regression analysis indicated that higher levels of cortisol were correlated with shorter LTL (p=0.003) above and beyond age and sex. Higher catecholamine levels were nearly-significant with shorter LTL (p=0.055). Neither hormone was correlated with shorter LTL in MDD (p's>0.28). To assess a possible cumulative effect of stress hormone activation, a summary score was calculated for each subject based on the number of stress hormone levels above the median for that group (HC or MDD). A significant inverse graded relationship was observed between LTL and the number of activated systems in HC (p=0.001), but not in MDD (p=0.96).

CONCLUSION

This pilot study provides preliminary evidence that stress hormone levels, especially cortisol, are inversely related to LTL in HC, but not in un-medicated MDD. Clarification of these relationships in larger samples could aid in understanding differential mechanisms underlying stress-related cellular aging in healthy and depressed populations.

Differential gene expression patterns between smokers and non-smokers: cause or consequence?

The molecular mechanisms causing smoking‐induced health decline are largely unknown. To elucidate the molecular pathways involved in cause and consequences of smoking behavior, we conducted a genome‐wide gene expression study in peripheral blood samples targeting 18 238 genes. Data of 743 smokers, 1686 never smokers and 890 ex‐smokers were available from two population‐based cohorts from the Netherlands. In addition, data of 56 monozygotic twin pairs discordant for ever smoking were used. One hundred thirty‐two genes were differentially expressed between current smokers and never smokers (P < 1.2 × 10⁻⁶, Bonferroni correction). The most significant genes were G protein‐coupled receptor 15 (P < 1 × 10⁻¹⁵⁰) and leucine‐rich repeat neuronal 3 (P < 1 × 10⁻⁴⁴). The smoking‐related genes were enriched for immune system, blood coagulation, natural killer cell and cancer pathways. By taking the data of ex‐smokers into account, expression of these 132 genes was classified into reversible (94 genes), slowly reversible (31 genes), irreversible (6 genes) or inconclusive (1 gene). Expression of 6 of the 132 genes (three reversible and three slowly reversible) was confirmed to be reactive to smoking as they were differentially expressed in monozygotic pairs discordant for smoking. Cis‐expression quantitative trait loci for GPR56 and RARRES3 (downregulated in smokers) were associated with increased number of cigarettes smoked per day in a large genome‐wide association meta‐analysis, suggesting a causative effect of GPR56 and RARRES3 expression on smoking behavior. In conclusion, differential gene expression patterns in smokers are extensive and cluster in several underlying disease pathways. Gene expression differences seem mainly direct consequences of smoking, and largely reversible after smoking cessation. However, we also identified DNA variants that may influence smoking behavior via the mediating gene expression.

Melancholic and atypical depression as predictor and moderator of outcome in cognitive behavior therapy and pharmacotherapy for adult depression

BACKGROUND

Melancholic and atypical depression are widely thought to moderate or predict outcome of pharmacological and psychological treatments of adult depression, but that has not yet been established. This study uses the data from four earlier trials comparing cognitive behavior therapy (CBT) versus antidepressant medications (ADMs; and pill placebo when available) to examine the extent to which melancholic and atypical depression moderate or predict outcome in an "individual patient data" meta-analysis.

METHODS

We conducted a systematic search for studies directly comparing CBT versus ADM, contacted the researchers, integrated the resulting datasets from these studies into one big dataset, and selected the studies that included melancholic or atypical depressive subtyping according to DSM-IV criteria at baseline (n = 4, with 805 patients). After multiple imputation of missing data at posttest, mixed models were used to conduct the main analyses.

RESULTS

In none of the analyses was melancholic or atypical depression found to significantly moderate outcome (indicating a better or worse outcome of these patients in CBT compared to ADM; i.e., an interaction), predict outcome independent of treatment group (i.e., a main effect), or predict outcome within a given modality. The outcome differences between patients with melancholia or atypical depression versus those without were consistently very small (all effect sizes g < 0.10).

CONCLUSIONS

We found no indication that melancholic or atypical depressions are significant or relevant moderators or predictors of outcome of CBT and ADM.

Prediction of 6-yr symptom course trajectories of anxiety disorders by diagnostic, clinical and psychological variables

This study aimed to identify course trajectories of anxiety disorder using a data-driven method and to determine the incremental predictive value of clinical and psychological variables over and above diagnostic categories. 703 patients with DSM-IV panic disorder with or without agoraphobia, agoraphobia, social phobia, or generalized anxiety disorder were selected from a prospective cohort study. Latent Growth Mixture Modeling was conducted, based on symptoms of anxiety and avoidance as assessed with the Life Chart Interview covering a 6-year time period. In 44% of the participants symptoms of anxiety and avoidance improved, in 24% remained stable, in 25% slightly increased, and in 7% severely increased. Identified course trajectories were predicted by baseline DSM-IV anxiety categories, clinical variables (i.e., severity and duration and level of disability) and psychological predictors (i.e., neuroticism, extraversion, anxiety sensitivity, worry, and rumination). Clinical variables better predicted unfavorable course trajectories than psychological predictors, over and above diagnostic categories.

A principal component meta-analysis on multiple anthropometric traits identifies novel loci for body shape

Large consortia have revealed hundreds of genetic loci associated with anthropometric traits, one trait at a time. We examined whether genetic variants affect body shape as a composite phenotype that is represented by a combination of anthropometric traits. We developed an approach that calculates averaged PCs (AvPCs) representing body shape derived from six anthropometric traits (body mass index, height, weight, waist and hip circumference, waist-to-hip ratio). The first four AvPCs explain >99% of the variability, are heritable, and associate with cardiometabolic outcomes. We performed genome-wide association analyses for each body shape composite phenotype across 65 studies and meta-analysed summary statistics. We identify six novel loci: LEMD2 and CD47 for AvPC1, RPS6KA5/C14orf159 and GANAB for AvPC3, and ARL15 and ANP32 for AvPC4. Our findings highlight the value of using multiple traits to define complex phenotypes for discovery, which are not captured by single-trait analyses, and may shed light onto new pathways.

Genetic variants in RBFOX3 are associated with sleep latency

Time to fall asleep (sleep latency) is a major determinant of sleep quality. Chronic, long sleep latency is a major characteristic of sleep-onset insomnia and/or delayed sleep phase syndrome. In this study we aimed to discover common polymorphisms that contribute to the genetics of sleep latency. We performed a meta-analysis of genome-wide association studies (GWAS) including 2 572 737 single nucleotide polymorphisms (SNPs) established in seven European cohorts including 4242 individuals. We found a cluster of three highly correlated variants (rs9900428, rs9907432 and rs7211029) in the RNA-binding protein fox-1 homolog 3 gene (RBFOX3) associated with sleep latency (P-values=5.77 × 10(-08), 6.59 × 10(-)(08) and 9.17 × 10(-)(08)). These SNPs were replicated in up to 12 independent populations including 30 377 individuals (P-values=1.5 × 10(-)(02), 7.0 × 10(-)(03) and 2.5 × 10(-)(03); combined meta-analysis P-values=5.5 × 10(-07), 5.4 × 10(-07) and 1.0 × 10(-07)). A functional prediction of RBFOX3 based on co-expression with other genes shows that this gene is predominantly expressed in brain (P-value=1.4 × 10(-316)) and the central nervous system (P-value=7.5 × 10(-)(321)). The predicted function of RBFOX3 based on co-expression analysis with other genes shows that this gene is significantly involved in the release cycle of neurotransmitters including gamma-aminobutyric acid and various monoamines (P-values<2.9 × 10(-11)) that are crucial in triggering the onset of sleep. To conclude, in this first large-scale GWAS of sleep latency we report a novel association of variants in RBFOX3 gene. Further, a functional prediction of RBFOX3 supports the involvement of RBFOX3 with sleep latency.

The genetics of blood pressure regulation and its target organs from association studies in 342,415 individuals

To dissect the genetic architecture of blood pressure and assess effects on target organ damage, we analyzed 128,272 SNPs from targeted and genome-wide arrays in 201,529 individuals of European ancestry, and genotypes from an additional 140,886 individuals were used for validation. We identified 66 blood pressure-associated loci, of which 17 were new; 15 harbored multiple distinct association signals. The 66 index SNPs were enriched for cis-regulatory elements, particularly in vascular endothelial cells, consistent with a primary role in blood pressure control through modulation of vascular tone across multiple tissues. The 66 index SNPs combined in a risk score showed comparable effects in 64,421 individuals of non-European descent. The 66-SNP blood pressure risk score was significantly associated with target organ damage in multiple tissues but with minor effects in the kidney. Our findings expand current knowledge of blood pressure-related pathways and highlight tissues beyond the classical renal system in blood pressure regulation.

Major depressive disorder

Major depressive disorder (MDD) is a debilitating disease that is characterized by depressed mood, diminished interests, impaired cognitive function and vegetative symptoms, such as disturbed sleep or appetite. MDD occurs about twice as often in women than it does in men and affects one in six adults in their lifetime. The aetiology of MDD is multifactorial and its heritability is estimated to be approximately 35%. In addition, environmental factors, such as sexual, physical or emotional abuse during childhood, are strongly associated with the risk of developing MDD. No established mechanism can explain all aspects of the disease. However, MDD is associated with alterations in regional brain volumes, particularly the hippocampus, and with functional changes in brain circuits, such as the cognitive control network and the affective-salience network. Furthermore, disturbances in the main neurobiological stress-responsive systems, including the hypothalamic-pituitary-adrenal axis and the immune system, occur in MDD. Management primarily comprises psychotherapy and pharmacological treatment. For treatment-resistant patients who have not responded to several augmentation or combination treatment attempts, electroconvulsive therapy is the treatment with the best empirical evidence. In this Primer, we provide an overview of the current evidence of MDD, including its epidemiology, aetiology, pathophysiology, diagnosis and treatment.

Increased mortality among people with anxiety disorders: total population study

BACKGROUND

Anxiety disorders and depression are the most common mental disorders worldwide and have a striking impact on global disease burden. Although depression has consistently been found to increase mortality; the role of anxiety disorders in predicting mortality risk is unclear.

AIMS

To assess mortality risk in people with anxiety disorders.

METHOD

We used nationwide Danish register data to conduct a prospective cohort study with over 30 million person-years of follow-up.

RESULTS

In total, 1066 (2.1%) people with anxiety disorders died during an average follow-up of 9.7 years. The risk of death by natural and unnatural causes was significantly higher among individuals with anxiety disorders (natural mortality rate ratio (MRR) = 1.39, 95% CI 1.28-1.51; unnatural MRR = 2.46, 95% CI 2.20-2.73) compared with the general population. Of those who died from unnatural causes, 16.5% had comorbid diagnoses of depression (MRR = 11.72, 95% CI 10.11-13.51).

CONCLUSIONS

Anxiety disorders significantly increased mortality risk. Comorbidity of anxiety disorders and depression played an important part in the increased mortality.

Correction: The Influence of Age and Sex on Genetic Associations with Adult Body Size and Shape: A Large-Scale Genome-Wide Interaction Study

[This corrects the article DOI: 10.1371/journal.pgen.1005378.].

Prevention of depression through nutritional strategies in high-risk persons: rationale and design of the MooDFOOD prevention trial

BACKGROUND

Obesity and depression are two prevalent conditions that are costly to individuals and society. The bidirectional association of obesity with depression, in which unhealthy dietary patterns may play an important role, has been well established. Few experimental studies have been conducted to investigate whether supplementing specific nutrients or improving diet and food-related behaviors can prevent depression in overweight persons.

METHOD/DESIGN

The MooDFOOD prevention trial examines the feasibility and effectiveness of two different nutritional strategies [multi-nutrient supplementation and food-related behavioral change therapy (FBC)] to prevent depression in individuals who are overweight and have elevated depressive symptoms but who are not currently or in the last 6 months meeting criteria for an episode of major depressive disorder (MDD). The randomized controlled prevention trial has a two-by-two factorial design: participants are randomized to daily multi-nutrient supplement (omega-3 fatty acids, calcium, selenium, B-11 vitamin and D-3 vitamin) versus placebo, and/or FBC therapy sessions versus usual care. Interventions last 12 months. In total 1000 participants aged 18-75 years with body mass index between 25-40 kg/m(2) and with a Patient Health Questionnaire-9 score ≥ 5 will be recruited at four study sites in four European countries. Baseline and follow-up assessments take place at 0, 3, 6, and 12 months. Primary endpoint is the onset of an episode of MDD, assessed according to DSM-IV based criteria using the MINI 5.0 interview. Depressive symptoms, anxiety, food and eating behavior, physical activity and health related quality of life are secondary outcomes. During the intervention, compliance, adverse events and potentially mediating variables are carefully monitored.

DISCUSSION

The trial aims to provide a better understanding of the causal role of specific nutrients, overall diet, and food-related behavior change with respect to the incidence of MDD episodes. This knowledge will be used to develop and disseminate innovative evidence-based, feasible, and effective nutritional public health strategies for the prevention of clinical depression.

TRIAL REGISTRATION

ClinicalTrials.gov. Number of identification: NCT02529423 . August 2015.

Pleiotropy between neuroticism and physical and mental health: findings from 108 038 men and women in UK Biobank

People with higher levels of neuroticism have an increased risk of several types of mental disorder. Higher neuroticism has also been associated, less consistently, with increased risk of various physical health outcomes. We hypothesised that these associations may, in part, be due to shared genetic influences. We tested for pleiotropy between neuroticism and 17 mental and physical diseases or health traits using linkage disequilibrium regression and polygenic profile scoring. Genetic correlations were derived between neuroticism scores in 108 038 people in the UK Biobank and health-related measures from 14 large genome-wide association studies (GWASs). Summary information for the 17 GWASs was used to create polygenic risk scores for the health-related measures in the UK Biobank participants. Associations between the health-related polygenic scores and neuroticism were examined using regression, adjusting for age, sex, genotyping batch, genotyping array, assessment centre and population stratification. Genetic correlations were identified between neuroticism and anorexia nervosa (rg=0.17), major depressive disorder (rg=0.66) and schizophrenia (rg=0.21). Polygenic risk for several health-related measures were associated with neuroticism, in a positive direction in the case of bipolar disorder, borderline personality, major depressive disorder, negative affect, neuroticism (Genetics of Personality Consortium), schizophrenia, coronary artery disease, and smoking (β between 0.009-0.043), and in a negative direction in the case of body mass index (β=-0.0095). A high level of pleiotropy exists between neuroticism and some measures of mental and physical health, particularly major depressive disorder and schizophrenia.

Does refining the phenotype improve replication rates? A review and replication of candidate gene studies on Major Depressive Disorder and Chronic Major Depressive Disorder

Replication has been poor for previously reported candidate genes involved in Major Depressive Disorder (MDD). One possible reason is phenotypic and genetic heterogeneity. The present study replicated genetic associations with MDD as defined in DSM-IV and with a more narrowly defined MDD subtype with a chronic and severe course. We first conducted a systematic review of genetic association studies on MDD published between September 2007 and June 2012 to identify all reported candidate genes. Genetic associations were then tested for all identified single nucleotide polymorphisms (SNPs) and the entire genes using data from the GAIN genome-wide association study (MDD: n = 1,352; chronic MDD subsample: n = 225; controls: n =  1,649). The 1,000 Genomes database was used as reference for imputation. From 157 studies identified inthe literature, 81 studies reported significant associations with MDD, involving 245 polymorphisms in 97 candidate genes, from which we were able to investigate 185 SNPs in 89 genes. We replicated nine candidate SNPs in eight genes for MDD and six in five genes for chronic MDD. However, these were not more than expected by chance. At gene level, we replicated 18 genes for MDD and 17 genes for chronic MDD, both significantly more than expected by chance. We showed that replication rates were improved for MDD compared to a previous, highly similar, replication study based on studies published before 2007. Effect sizes of the SNPs and replication rates of the candidate genes were improved in the chronic subsample compared to the full sample. Nonetheless, replication rates were still poor.

Childhood maltreatment, maladaptive personality types and level and course of psychological distress: A six-year longitudinal study

BACKGROUND

Childhood maltreatment and maladaptive personality are both cross-sectionally associated with psychological distress. It is unknown whether childhood maltreatment affects the level and longitudinal course of psychological distress in adults and to what extent this effect is mediated by maladaptive personality.

METHODS

A sample of 2947 adults aged 18-65, consisting of healthy controls, persons with a prior history or current episode of depressive and/or anxiety disorders according to the Composite Interview Diagnostic Instrument were assessed in six waves at baseline (T0) and 1 (T1), 2 (T2), 4 (T4) and 6 years (T6) later. At each wave psychological distress was measured with the Inventory of Depressive Symptomatology, Beck Anxiety Inventory, and Fear Questionnaire. At T0 childhood maltreatment types were measured with a semi-structured interview (Childhood Trauma Interview) and personality traits with the NEO-Five Factor Inventory.

RESULTS

Using latent variable analyses, we found that severity of childhood maltreatment (emotional neglect and abuse in particular) predicted higher initial levels of psychological distress and that this effect was mediated by maladaptive personality types. Differences in trajectories of distress between persons with varying levels of childhood maltreatment remained significant and stable over time.

LIMITATIONS

Childhood maltreatment was assessed retrospectively and maladaptive personality types and level of psychological distress at study entry were assessed concurrently.

CONCLUSIONS

Routine assessment of maladaptive personality types and possible childhood emotional maltreatment in persons with severe and prolonged psychological distress seems warranted to identify persons who may need a different or more intensive treatment.

Interactions between uncoupling protein 2 gene polymorphisms, obesity and alcohol intake on liver function: a large meta-analysed population-based study

BACKGROUND AND OBJECTIVE

Given the role of uncoupling protein 2 (UCP2) in the accumulation of fat in the hepatocytes and in the enhancement of protective mechanisms in acute ethanol intake, we hypothesised that UCP2 polymorphisms are likely to cause liver disease through their interactions with obesity and alcohol intake. To test this hypothesis, we investigated the interaction between tagging polymorphisms in the UCP2 gene (rs2306819, rs599277 and rs659366), alcohol intake and obesity traits such as BMI and waist circumference (WC) on alanine aminotransferase (ALT) and gamma glutamyl transferase (GGT) in a large meta-analysis of data sets from three populations (n=20 242).

DESIGN AND METHODS

The study populations included the Northern Finland Birth Cohort 1966 (n=4996), Netherlands Study of Depression and Anxiety (n=1883) and LifeLines Cohort Study (n=13 363). Interactions between the polymorphisms and obesity and alcohol intake on dichotomised ALT and GGT levels were assessed using logistic regression and the likelihood ratio test.

RESULTS

In the meta-analysis of the three cohorts, none of the three UCP2 polymorphisms were associated with GGT or ALT levels. There was no evidence for interaction between the polymorphisms and alcohol intake on GGT and ALT levels. In contrast, the association of WC and BMI with GGT levels varied by rs659366 genotype (Pinteraction=0.03 and 0.007, respectively; adjusted for age, gender, high alcohol intake, diabetes, hypertension and serum lipid concentrations).

CONCLUSION

In conclusion, our findings in 20 242 individuals suggest that UCP2 gene polymorphisms may cause liver dysfunction through the interaction with body fat rather than alcohol intake.

The genetics of alcohol dependence: Twin and SNP-based heritability, and genome-wide association study based on AUDIT scores

Alcohol dependence (AD) is among the most common and costly public health problems contributing to morbidity and mortality throughout the world. In this study, we investigate the genetic basis of AD in a Dutch population using data from the Netherlands Twin Register (NTR) and the Netherlands Study of Depression and Anxiety (NESDA). The presence of AD was ascertained via the Alcohol Use Disorders Identification Test (AUDIT) applying cut-offs with good specificity and sensitivity in identifying those at risk for AD. Twin-based heritability of AD-AUDIT was estimated using structural equation modeling of data in 7,694 MZ and DZ twin pairs. Variance in AD-AUDIT explained by all SNPs was estimated with genome-wide complex trait analysis (GCTA). A genome-wide association study (GWAS) was performed in 7,842 subjects. GWAS SNP effect concordance analysis was performed between our GWAS and a recent AD GWAS using DSM-IV diagnosis. The twin-based heritability of AD-AUDIT was estimated at 60% (55-69%). GCTA showed that common SNPs jointly capture 33% (SE = 0.12, P = 0.002) of this heritability. In the GWAS, the top hits were positioned within four regions (4q31.1, 2p16.1, 6q25.1, 7p14.1) with the strongest association detected for rs55768019 (P = 7.58 × 10(-7) ). This first GWAS of AD using the AUDIT measure found results consistent with previous genetic studies using DSM diagnosis: concordance in heritability estimates and direction of SNPs effect and overlap with top hits from previous GWAS. Thus, the use of appropriate questionnaires may represent cost-effective strategies to phenotype samples in large-scale biobanks or other population-based datasets.

Symptom dimensions of affective disorders in migraine patients

OBJECTIVE

A strong association has been established between migraine and depression. However, this is the first study to differentiate in a large sample of migraine patients for symptom dimensions of the affective disorder spectrum.

METHODS

Migraine patients (n=3174) from the LUMINA (Leiden University Medical Centre Migraine Neuro-analysis Program) study and patients with current psychopathology (n=1129), past psychopathology (n=477), and healthy controls (n=561) from the NESDA (Netherlands Study of Depression and Anxiety) study, were compared for three symptom dimensions of depression and anxiety. The dimensions -lack of positive affect (depression specific); negative affect (nonspecific); and somatic arousal (anxiety specific)- were assessed by a shortened adaptation of the Mood and Anxiety Symptom Questionnaire (MASQ-D30). Within the migraine group, the association with migraine specific determinants was established. Multivariate regression analyses were conducted.

RESULTS

Migraine patients differed significantly (p<0.001) from healthy controls for all three dimensions: Cohen's d effect sizes were 0.37 for lack of positive affect, 0.68 for negative affect, and 0.75 for somatic arousal. For the lack of positive affect and negative affect dimensions, migraine patients were predominantly similar to the past psychopathology group. For the somatic arousal dimension, migraine patients scores were more comparable with the current psychopathology group. Migraine specific determinants for high scores on all dimensions were high frequency of attacks and cutaneous allodynia during attacks.

CONCLUSION

This study shows that affective symptoms in migraine patients are especially associated with the somatic arousal component.

The Influence of Age and Sex on Genetic Associations with Adult Body Size and Shape: A Large-Scale Genome-Wide Interaction Study

Genome-wide association studies (GWAS) have identified more than 100 genetic variants contributing to BMI, a measure of body size, or waist-to-hip ratio (adjusted for BMI, WHR_adjBMI), a measure of body shape. Body size and shape change as people grow older and these changes differ substantially between men and women. To systematically screen for age- and/or sex-specific effects of genetic variants on BMI and WHR_adjBMI, we performed meta-analyses of 114 studies (up to 320,485 individuals of European descent) with genome-wide chip and/or Metabochip data by the Genetic Investigation of Anthropometric Traits (GIANT) Consortium. Each study tested the association of up to ~2.8M SNPs with BMI and WHR_adjBMI in four strata (men ≤50y, men >50y, women ≤50y, women >50y) and summary statistics were combined in stratum-specific meta-analyses. We then screened for variants that showed age-specific effects (G x AGE), sex-specific effects (G x SEX) or age-specific effects that differed between men and women (G x AGE x SEX). For BMI, we identified 15 loci (11 previously established for main effects, four novel) that showed significant (FDR<5%) age-specific effects, of which 11 had larger effects in younger (<50y) than in older adults (≥50y). No sex-dependent effects were identified for BMI. For WHR_adjBMI, we identified 44 loci (27 previously established for main effects, 17 novel) with sex-specific effects, of which 28 showed larger effects in women than in men, five showed larger effects in men than in women, and 11 showed opposite effects between sexes. No age-dependent effects were identified for WHR_adjBMI. This is the first genome-wide interaction meta-analysis to report convincing evidence of age-dependent genetic effects on BMI. In addition, we confirm the sex-specificity of genetic effects on WHR_adjBMI. These results may provide further insights into the biology that underlies weight change with age or the sexually dimorphism of body shape.

Adult body size and body shape differ substantially between men and women and change over time. More than 100 genetic variants that influence body mass index (measure of body size) or waist-to-hip ratio (measure of body shape) have been identified. While there is evidence that some genetic loci affect body shape differently in men than in women, little is known about whether genetic effects differ in older compared to younger adults, and whether such changes differ between men and women. Therefore, we conducted a systematic genome-wide search, including 114 studies (>320,000 individuals), to specifically identify genetic loci with age- and or sex-dependent effects on body size and shape. We identified 15 loci of which the effect on BMI was different in older compared to younger adults, whereas we found no evidence for loci with different effects in men compared to women. The opposite was seen for body shape as we identified 44 loci of which the effect on waist-to-hip ratio differed between men and women, but no difference between younger and older adults were observed. Our observations may provide new insights into the biology that underlies weight change with age or the sexual dimorphism of body shape.

Psychiatric disorders and leukocyte telomere length: Underlying mechanisms linking mental illness with cellular aging

Many psychiatric illnesses are associated with early mortality and with an increased risk of developing physical diseases that are more typically seen in the elderly. Moreover, certain psychiatric illnesses may be associated with accelerated cellular aging, evidenced by shortened leukocyte telomere length (LTL), which could underlie this association. Shortened LTL reflects a cell's mitotic history and cumulative exposure to inflammation and oxidation as well as the availability of telomerase, a telomere-lengthening enzyme. Critically short telomeres can cause cells to undergo senescence, apoptosis or genomic instability, and shorter LTL correlates with poorer health and predicts mortality. Emerging data suggest that LTL may be reduced in certain psychiatric illnesses, perhaps in proportion to exposure to the psychiatric illnesses, although conflicting data exist. Telomerase has been less well characterized in psychiatric illnesses, but a role in depression and in antidepressant and neurotrophic effects has been suggested by preclinical and clinical studies. In this article, studies on LTL and telomerase activity in psychiatric illnesses are critically reviewed, potential mediators are discussed, and future directions are suggested. A deeper understanding of cellular aging in psychiatric illnesses could lead to re-conceptualizing them as systemic illnesses with manifestations inside and outside the brain and could identify new treatment targets.

IDENTIFYING PANIC DISORDER SUBTYPES USING FACTOR MIXTURE MODELING

BACKGROUND

The clinical presentation of panic disorder (PD) is known to be highly heterogeneous, complicating research on its etiology, neurobiological pathways, and treatment. None of the attempts to identify PD subtypes have been independently reproduced, rendering the current literature inconclusive.

METHODS

Using a data-driven, case-centered approach (factor mixture modeling) on a broad range of anxiety symptoms assessed with the Beck anxiety inventory, the present study identifies PD disorder subtypes in a large (n = 658), well-documented mixed-population sample from the Netherlands Study of Depression and Anxiety (NESDA), with subtypes being validated and detailed using a variety of clinical characteristics.

RESULTS

A three-class, one-factor model proved superior to all other possible models (Bayesian information criterion = 13,200; Lo-Mendel-Rubin = 0.0295; bootstrapped likelihood ratio test ≤ 0.0001), with the first class, a cognitive-autonomic subtype, accounting for 29.8%, the second class, the autonomic subtype, for 29.9%, and a third class, the aspecific subtype, for 40.3% of the population. The cognitive-autonomic and autonomic subtypes showed significant differences compared to the aspecific subtype (e.g., comorbidity and suicide attempts) but on severity differed between themselves only.

CONCLUSION

Three qualitatively different PD subtypes were identified: a severe cognitive-autonomic subtype, a moderate autonomic subtype, and a mild aspecific subtype. Qualitative and quantitative differences were related to severity and clinical properties such as comorbidity, suicide attempts, sleep, and sense of mastery.

Common rather than unique aspects of repetitive negative thinking are related to depressive and anxiety disorders and symptoms

Repetitive Negative Thinking (RNT) is assumed to be a transdiagnostic factor in depressive and anxiety disorders. We hypothesized that an underlying common dimension of RNT will be more strongly associated with each of the anxiety and depressive disorders, with comorbidity among disorders and with symptom severity than unique aspects of rumination and worry. In a cross-sectional study, 2143 adults diagnosed according to DSM-IV criteria completed questionnaires for content-independent RNT, rumination and worry. 84% of the shared variance of worry and rumination overlapped with content-independent RNT. The common dimension of RNT was significantly associated with each of the depressive and anxiety disorders, comorbidity among emotional disorders and the common core of depressive, anxiety and avoidance symptoms. The unique portion of rumination showed a significant relationship with Major Depressive Disorder and depressive comorbidity and the unique portion of worry with Generalized Anxiety Disorder. These findings are particularly relevant for clinical practice as generic interventions to reduce RNT are currently being tested.

Genome-wide association study of kidney function decline in individuals of European descent

Genome-wide association studies (GWASs) have identified multiple loci associated with cross-sectional eGFR, but a systematic genetic analysis of kidney function decline over time is missing. Here we conducted a GWAS meta-analysis among 63,558 participants of European descent, initially from 16 cohorts with serial kidney function measurements within the CKDGen Consortium, followed by independent replication among additional participants from 13 cohorts. In stage 1 GWAS meta-analysis, single-nucleotide polymorphisms (SNPs) at MEOX2, GALNT11, IL1RAP, NPPA, HPCAL1, and CDH23 showed the strongest associations for at least one trait, in addition to the known UMOD locus, which showed genome-wide significance with an annual change in eGFR. In stage 2 meta-analysis, the significant association at UMOD was replicated. Associations at GALNT11 with Rapid Decline (annual eGFR decline of 3 ml/min per 1.73 m(2) or more), and CDH23 with eGFR change among those with CKD showed significant suggestive evidence of replication. Combined stage 1 and 2 meta-analyses showed significance for UMOD, GALNT11, and CDH23. Morpholino knockdowns of galnt11 and cdh23 in zebrafish embryos each had signs of severe edema 72 h after gentamicin treatment compared with controls, but no gross morphological renal abnormalities before gentamicin administration. Thus, our results suggest a role in the deterioration of kidney function for the loci GALNT11 and CDH23, and show that the UMOD locus is significantly associated with kidney function decline.

Age- and sex-specific causal effects of adiposity on cardiovascular risk factors

Observational studies have reported different effects of adiposity on cardiovascular risk factors across age and sex. Since cardiovascular risk factors are enriched in obese individuals, it has not been easy to dissect the effects of adiposity from those of other risk factors. We used a Mendelian randomization approach, applying a set of 32 genetic markers to estimate the causal effect of adiposity on blood pressure, glycemic indices, circulating lipid levels, and markers of inflammation and liver disease in up to 67,553 individuals. All analyses were stratified by age (cutoff 55 years of age) and sex. The genetic score was associated with BMI in both nonstratified analysis (P = 2.8 × 10(-107)) and stratified analyses (all P < 3.3 × 10(-30)). We found evidence of a causal effect of adiposity on blood pressure, fasting levels of insulin, C-reactive protein, interleukin-6, HDL cholesterol, and triglycerides in a nonstratified analysis and in the <55-year stratum. Further, we found evidence of a smaller causal effect on total cholesterol (P for difference = 0.015) in the ≥55-year stratum than in the <55-year stratum, a finding that could be explained by biology, survival bias, or differential medication. In conclusion, this study extends previous knowledge of the effects of adiposity by providing sex- and age-specific causal estimates on cardiovascular risk factors.

Modulation of genetic associations with serum urate levels by body-mass-index in humans

We tested for interactions between body mass index (BMI) and common genetic variants affecting serum urate levels, genome-wide, in up to 42569 participants. Both stratified genome-wide association (GWAS) analyses, in lean, overweight and obese individuals, and regression-type analyses in a non BMI-stratified overall sample were performed. The former did not uncover any novel locus with a major main effect, but supported modulation of effects for some known and potentially new urate loci. The latter highlighted a SNP at RBFOX3 reaching genome-wide significant level (effect size 0.014, 95% CI 0.008-0.02, Pinter= 2.6 x 10-8). Two top loci in interaction term analyses, RBFOX3 and ERO1LB-EDARADD, also displayed suggestive differences in main effect size between the lean and obese strata. All top ranking loci for urate effect differences between BMI categories were novel and most had small magnitude but opposite direction effects between strata. They include the locus RBMS1-TANK (men, Pdifflean-overweight= 4.7 x 10-8), a region that has been associated with several obesity related traits, and TSPYL5 (men, Pdifflean-overweight= 9.1 x 10-8), regulating adipocytes-produced estradiol. The top-ranking known urate loci was ABCG2, the strongest known gout risk locus, with an effect halved in obese compared to lean men (Pdifflean-obese= 2 x 10-4). Finally, pathway analysis suggested a role for N-glycan biosynthesis as a prominent urate-associated pathway in the lean stratum. These results illustrate a potentially powerful way to monitor changes occurring in obesogenic environment.

Increased prevalence of ECG markers for sudden cardiac arrest in refractory epilepsy

BACKGROUND AND AIM

People with epilepsy are at increased risk of sudden cardiac arrest (SCA) due to ECG-confirmed ventricular tachycardia/fibrillation, as seen in a community-based study. We aimed to determine whether ECG-risk markers of SCA are more prevalent in people with epilepsy.

METHODS

In a cross-sectional, retrospective study, we analysed the ECG recordings of 185 people with refractory epilepsy and 178 controls without epilepsy. Data on epilepsy characteristics, cardiac comorbidity, and drug use were collected, and general ECG variables (heart rate (HR), PQ and QRS intervals) assessed. We analysed ECGs for three markers of SCA risk: severe QTc prolongation (male >450 ms, female >470 ms), Brugada ECG pattern, and early repolarisation pattern (ERP). Multivariate regression models were used to analyse differences between groups, and to identify associated clinical and epilepsy-related characteristics.

RESULTS

People with epilepsy had higher HR (71 vs 62 bpm, p<0.001) and a longer PQ interval (162.8 vs 152.6 ms, p=0.001). Severe QTc prolongation and ERP were more prevalent in people with epilepsy (QTc prolongation: 5% vs 0%; p=0.002; ERP: 34% vs 13%, p<0.001), while the Brugada ECG pattern was equally frequent in both groups (2% vs 1%, p>0.999). After adjustment for covariates, epilepsy remained associated with ERP (ORadj 2.4, 95% CI 1.1 to 5.5) and severe QTc prolongation (ORadj 9.9, 95% CI 1.1 to 1317.7).

CONCLUSIONS

ERP and severe QTc prolongation appear to be more prevalent in people with refractory epilepsy. Future studies must determine whether this contributes to increased SCA risk in people with epilepsy.

New genetic loci link adipose and insulin biology to body fat distribution

Body fat distribution is a heritable trait and a well-established predictor of adverse metabolic outcomes, independent of overall adiposity. To increase our understanding of the genetic basis of body fat distribution and its molecular links to cardiometabolic traits, we conducted genome-wide association meta-analyses of waist and hip circumference-related traits in up to 224,459 individuals. We identified 49 loci (33 new) associated with waist-to-hip ratio adjusted for body mass index (WHRadjBMI) and an additional 19 loci newly associated with related waist and hip circumference measures (P<5×10⁻⁸). Twenty of the 49 WHRadjBMI loci showed significant sexual dimorphism, 19 of which displayed a stronger effect in women. The identified loci were enriched for genes expressed in adipose tissue and for putative regulatory elements in adipocytes. Pathway analyses implicated adipogenesis, angiogenesis, transcriptional regulation, and insulin resistance as processes affecting fat distribution, providing insight into potential pathophysiological mechanisms.

DISC1 gene and affective psychopathology: a combined structural and functional MRI study

The gene Disrupted-In-Schizophrenia-1 (DISC1) has been indicated as a determinant of psychopathology, including affective disorders, and shown to influence prefrontal cortex (PFC) and hippocampus functioning, regions of major interest for affective disorders. We aimed to investigate whether DISC1 differentially modulates brain function during executive and memory processing, and morphology in regions relevant for depression and anxiety disorders (affective disorders). 128 participants, with (n = 103) and without (controls; n = 25) affective disorders underwent genotyping for Ser704Cys (with Cys-allele considered as risk-allele) and structural and functional (f) Magnetic Resonance Imaging (MRI) during visuospatial planning and emotional episodic memory tasks. For both voxel-based morphometry and fMRI analyses, we investigated the effect of genotype in controls and explored genotypeXdiagnosis interactions. Results are reported at p < 0.05 FWE small volume corrected. In controls, Cys-carriers showed smaller bilateral (para)hippocampal volumes compared with Ser-homozygotes, and lower activation in the anterior cingulate cortex (ACC) and dorsolateral PFC during visuospatial planning. In anxiety patients, Cys-carriers showed larger (para)hippocampal volumes and more ACC activation during visuospatial planning. In depressive patients, no effect of genotype was observed and overall, no effect of genotype on episodic memory processing was detected. We demonstrated that Ser704Cys-genotype influences (para)hippocampal structure and functioning the dorsal PFC during executive planning, most prominently in unaffected controls. Results suggest that presence of psychopathology moderates Ser704Cys effects.

A longitudinal study of experiential avoidance in emotional disorders

The aim of this study was to examine the degree in which measurements of trait experiential avoidance (EA) are affected by current emotional disorder and whether EA is a causal factor in the course of emotional disorders (anxiety and depressive disorders) and the development of comorbidity among emotional disorders. In a sample of 2,316 adults aged 18 to 65, consisting of healthy controls, persons with a prior history of emotional disorders, and persons with a current emotional disorder, DSM-IV-based emotional disorders (CIDI: Composite Interview Diagnostic Instrument) were assessed at T2 and 2 (T4) and 4years later (T6) and experiential avoidance (AAQ: Acceptance and Action Questionnaire) at T2 and T4. Results showed that EA scores were stable over a 2-year period notwithstanding state fluctuations because of current emotional disorder. Moreover, EA scores at T2 predicted changes in distress (major depressive disorder, dysthymia, generalized anxiety disorder) and in fear disorders (social anxiety disorder, panic disorder with or without agoraphobia, agoraphobia without panic) at T4. Finally, EA at T4 mediated the longitudinal association of fear disorders at T2 with distress disorders at T6 as well as of distress disorders at T2 with fear disorders at T6. These findings suggest that EA scores are more than epiphenomena of emotional disorders and that EA may be conceptualized as a relevant transdiagnostic factor affecting the course and development of comorbidity of emotional disorders.

Association of vitamin D status with arterial blood pressure and hypertension risk: a mendelian randomisation study

BACKGROUND

Low plasma 25-hydroxyvitamin D (25[OH]D) concentration is associated with high arterial blood pressure and hypertension risk, but whether this association is causal is unknown. We used a mendelian randomisation approach to test whether 25(OH)D concentration is causally associated with blood pressure and hypertension risk.

METHODS

In this mendelian randomisation study, we generated an allele score (25[OH]D synthesis score) based on variants of genes that affect 25(OH)D synthesis or substrate availability (CYP2R1 and DHCR7), which we used as a proxy for 25(OH)D concentration. We meta-analysed data for up to 108 173 individuals from 35 studies in the D-CarDia collaboration to investigate associations between the allele score and blood pressure measurements. We complemented these analyses with previously published summary statistics from the International Consortium on Blood Pressure (ICBP), the Cohorts for Heart and Aging Research in Genomic Epidemiology (CHARGE) consortium, and the Global Blood Pressure Genetics (Global BPGen) consortium.

FINDINGS

In phenotypic analyses (up to n=49 363), increased 25(OH)D concentration was associated with decreased systolic blood pressure (β per 10% increase, -0·12 mm Hg, 95% CI -0·20 to -0·04; p=0·003) and reduced odds of hypertension (odds ratio [OR] 0·98, 95% CI 0·97-0·99; p=0·0003), but not with decreased diastolic blood pressure (β per 10% increase, -0·02 mm Hg, -0·08 to 0·03; p=0·37). In meta-analyses in which we combined data from D-CarDia and the ICBP (n=146 581, after exclusion of overlapping studies), each 25(OH)D-increasing allele of the synthesis score was associated with a change of -0·10 mm Hg in systolic blood pressure (-0·21 to -0·0001; p=0·0498) and a change of -0·08 mm Hg in diastolic blood pressure (-0·15 to -0·02; p=0·01). When D-CarDia and consortia data for hypertension were meta-analysed together (n=142 255), the synthesis score was associated with a reduced odds of hypertension (OR per allele, 0·98, 0·96-0·99; p=0·001). In instrumental variable analysis, each 10% increase in genetically instrumented 25(OH)D concentration was associated with a change of -0·29 mm Hg in diastolic blood pressure (-0·52 to -0·07; p=0·01), a change of -0·37 mm Hg in systolic blood pressure (-0·73 to 0·003; p=0·052), and an 8·1% decreased odds of hypertension (OR 0·92, 0·87-0·97; p=0·002).

INTERPRETATION

Increased plasma concentrations of 25(OH)D might reduce the risk of hypertension. This finding warrants further investigation in an independent, similarly powered study.

FUNDING

British Heart Foundation, UK Medical Research Council, and Academy of Finland.

Bipolar polygenic loading and bipolar spectrum features in major depressive disorder

OBJECTIVES

Family and genetic studies indicate overlapping liability for major depressive disorder and bipolar disorder. The purpose of the present study was to determine whether this shared genetic liability influences clinical presentation.

METHODS

A polygenic risk score for bipolar disorder, derived from a large genome-wide association meta-analysis, was generated for each subject of European-American ancestry (n = 1,274) in the Sequential Treatment Alternatives to Relieve Depression study (STAR*D) outpatient major depressive disorder cohort. A hypothesis-driven approach was used to test for association between bipolar disorder risk score and features of depression associated with bipolar disorder in the literature. Follow-up analyses were performed in two additional cohorts.

RESULTS

A generalized linear mixed model including seven features hypothesized to be associated with bipolar spectrum illness was significantly associated with bipolar polygenic risk score [F = 2.07, degrees of freedom (df) = 7, p = 0.04]. Features included early onset, suicide attempt, recurrent depression, atypical depression, subclinical mania, subclinical psychosis, and severity. Post-hoc univariate analyses demonstrated that the major contributors to this omnibus association were onset of illness at age ≤ 18 years [odds ratio (OR) = 1.2, p = 0.003], history of suicide attempt (OR = 1.21, p = 0.03), and presence of at least one manic symptom (OR = 1.16, p = 0.02). The maximal variance in these traits explained by polygenic score ranged from 0.8% to 1.1%. However, analyses in two replication cohorts testing a five-feature model did not support this association.

CONCLUSIONS

Bipolar genetic loading appeared to be associated with bipolar-like presentation in major depressive disorder in the primary analysis. However, the results were at most inconclusive because of lack of replication. Replication efforts were challenged by different ascertainment and assessment strategies in the different cohorts. The methodological approach described here may prove useful in applying genetic data to clarify psychiatric nosology in future studies.