The Munich vulnerability study on affective disorders: premorbid psychometric profile of affected individuals

Polymorphism in Tmem132d regulates expression and anxiety-related behavior through binding of RNA polymerase II complex

TMEM132D is a candidate gene, where risk genotypes have been associated with anxiety severity along with higher mRNA expression in the frontal cortex of panic disorder patients. Concurrently, in a high (HAB) and low (LAB) trait anxiety mouse model, Tmem132d was found to show increased expression in the anterior cingulate cortex (aCC) of HAB as compared to LAB mice. To understand the molecular underpinnings underlying the differential expression, we sequenced the gene and found two single-nucleotide polymorphisms (SNPs) in the promoter differing between both lines which could explain the observed mRNA expression profiles using gene reporter assays. In addition, there was no difference in basal DNA methylation in the CpG Island that encompasses the HAB vs. LAB Tmem132d promoter region. Furthermore, we found significantly higher binding of RNA polymerase II (POLR2A) to the proximal HAB-specific SNP (rs233264624) than the corresponding LAB locus in an oligonucleotide pull-down assay, suggesting increased transcription. Virus mediated overexpression of Tmem132d in the aCC of C57BL/6 J mice could confirm its role in mediating an anxiogenic phenotype. To model gene-environmental interactions, HAB mice exposed to enriched environment (HAB-EE) responded with decreased anxiety levels but, had enhanced Tmem132d mRNA expression as compared to standard-housed HAB (HAB-SH) mice. While LAB mice subjected to unpredictable chronic mild stress (LAB-UCMS) exhibited higher anxiety levels and had lower mRNA expression compared to standard-housed LAB (LAB-SH) mice. Chromatin immunoprecipitation revealed significantly higher binding of POLR2A to rs233264624 in HAB-EE, while LAB-UCMS had lower POLR2A binding at this locus, thus explaining the enhanced or attenuated expression of Tmem132d compared to their respective SH controls. To further investigate gene-environment interactions, DNA methylation was assessed using Illumina 450 K BeadChip in 74 panic disorder patients. Significant methylation differences were observed in two CpGs (cg26322591 and cg03283235) located in TMEM132D depending on the number of positive life events supporting the results of an influence of positive environmental cues on regulation of Tmem132d expression in mice.

A familial risk enriched cohort as a platform for testing early interventions to prevent severe mental illness

BACKGROUND

Severe mental illness (SMI), including schizophrenia, bipolar disorder and severe depression, is responsible for a substantial proportion of disability in the population. This article describes the aims and design of a research study that takes a novel approach to targeted prevention of SMI. It is based on the rationale that early developmental antecedents to SMI are likely to be more malleable than fully developed mood or psychotic disorders and that low-risk interventions targeting antecedents may reduce the risk of SMI.

METHODS/DESIGN

Families Overcoming Risks and Building Opportunities for Well-being (FORBOW) is an accelerated cohort study that includes a large proportion of offspring of parents with SMI and embeds intervention trials in a cohort multiple randomized controlled trial (cmRCT) design. Antecedents are conditions of the individual that are distressing but not severely impairing, predict SMI with moderate-to-large effect sizes and precede the onset of SMI by at least several years. FORBOW focuses on the following antecedents: affective lability, anxiety, psychotic-like experiences, basic symptoms, sleep problems, somatic symptoms, cannabis use and cognitive delay. Enrolment of offspring over a broad age range (0 to 21 years) will allow researchers to draw conclusions on a longer developmental period from a study of shorter duration. Annual assessments cover a full range of psychopathology, cognitive abilities, eligibility criteria for interventions and outcomes. Pre-emptive early interventions (PEI) will include skill training for parents of younger children and courses in emotional well-being skills based on cognitive behavioural therapy for older children and youth. A sample enriched for familial risk of SMI will enhance statistical power for testing the efficacy of PEI.

DISCUSSION

FORBOW offers a platform for efficient and unbiased testing of interventions selected according to best available evidence. Since few differences exist between familial and 'sporadic' SMI, the same interventions are likely to be effective in the general population. Comparison of short-term efficacy of PEI on antecedents and the long term efficacy for preventing the onset of SMI will provide an experimental test of the etiological role of antecedents in the development of SMI.

Influence of the number and severity of somatic symptoms on the severity of depression and suicidality in community-dwelling elders

INTRODUCTION

Older adults commonly experience somatic symptoms, and those who do are more likely to have depressive disorders as well. Our goal in this study is to examine the influence of the number and severity of somatic symptoms on the severity of depressive symptoms, including suicidality, in elderly adults.

METHODS

This study was conducted as part of the Ansan Geriatric (AGE) Study, a community-based cohort study in Ansan City, South Korea. A total of 3,210 elderly adults aged 60 years or over (1,388 males and 1,770 females) participated in this study. The Korean version of the Beck Depression Inventory (BDI) was used to measure depressive symptoms and suicidality. Somatic symptoms were assessed by the Patient Health Questionnaire-15 (PHQ-15).

RESULTS

Both mild and severe somatic symptoms significantly increased the risk for severe depression and high suicidality. Severe somatic symptoms doubled the risk for severe depression and suicidal intent.

DISCUSSION

Somatic symptoms not fully explained as medical illnesses are closely associated with late-life depression, even after adjustments for comorbid physical illnesses and other confounding factors. The presence of somatic symptoms concurrent with, but not fully explained by comorbid physical illness or disability, seems to be an independent marker for predicting the severity of late-life depression and suicidality.

Variants within the GABA transaminase (ABAT) gene region are associated with somatosensory evoked EEG potentials in families at high risk for affective disorders

BACKGROUND

Depression frequently co-occurs with somatization, and somatic complaints have been reported as a vulnerability marker for affective disorders observable before disease onset. Somatization is thought to result from an increased attention to somatic sensations, which should be reflected in long-latency somatosensory evoked electroencephalogram (EEG) potentials (SSEPs) at the physiological level. Previous studies revealed that SSEPs are altered in depressed patients and suggested late SSEP components as vulnerability markers for affective disorders. Neurotransmitters such as serotonin, γ-aminobutyric acid (GABA) and the neuropeptide substance P may play an important role for both affective disorders and somatosensory processing. Method We investigated the associations between SSEPs and polymorphisms within candidate genes of the serotonergic, GABAergic as well as the substance P system in subjects at high risk for affective disorders. The sample was composed of high-risk families participating in the Munich Vulnerability Study and genetic association analyses were calculated using qfam (family-based association tests for quantitative traits) implemented in PLINK 1.05.

RESULTS

We observed significant associations (false discovery rate <0.05) withstanding correction for multiple testing between late SSEP components (response strength 170-370 ms after stimulation) and four single nucleotide polymorphisms within the GABA transaminase (ABAT) gene region coding for a protein responsible for GABA degradation. No effects were found with the classical disease trait approach, suggesting SSEP marker specificity of the observed associations.

CONCLUSIONS

Our findings point to a possible role of ABAT gene-regulated GABA catabolism for an altered processing of somatosensory stimuli as a potential vulnerability marker for affective disorders.

IPS multicentric study: Functional somatic symptoms in depression

BACKGROUND

As a pilot project, Indian Psychiatric Society conducted the first multicentric study involving diverse settings from teaching institutions in public and private sectors and even privately run psychiatric clinics.

AIM OF THE STUDY

To study the typology of functional somatic complaints (FSC) in patients with first episode depression.

MATERIALS AND METHODS

A total of 741 patients from 16 centers across the country participated in the study. They were assessed on Bradford Somatic Symptom inventory for FSC, Beck Depression Inventory for severity of depression, and Comprehensive Psychopathological Rating Scale- anxiety index (CPRS-AI) for anxiety symptoms.

RESULTS

The mean age of the study sample was 38.23 years (SD-11.52). There was equal gender distribution (male - 49.8% vs. females 50.2%). Majority of the patients were married (74.5%), Hindus (57%), and from nuclear family (68.2%). A little over half of the patients were from urban background (52.9%). The mean duration of illness at the time of assessment was 25.55 months. Most of the patients (77%) had more than 10 FSCs, with 39.7% having more than 20 FSCs as assessed on Bradford Somatic Inventory. The more common FSC as assessed on Bradford Somatic Inventory were lack of energy (weakness) much of the time (76.2%), severe headache (74%) and feeling tired when not working (71%), pain in legs (64%), aware of palpitations (59.5%), head feeling heavy (59.4%), aches and pains all over the body (55.5%), mouth or throat getting dry (55.2%), pain or tension in neck and shoulder (54%), head feeling hot or burning (54%), and darkness or mist in front of the eyes (49.1%). The prevalence and typology of FSCs is to a certain extent influenced by the sociodemographic variables and severity of depression.

CONCLUSION

Functional somatic symptoms are highly prevalent in Indian depressed patients and hence deserve more attention while diagnosing depression in Indian setting.

Somatization in major depression--clinical features and genetic associations

OBJECTIVE

To identify clinical variables and genetic variations within monoaminergic genes known to be implicated in pain perception that are associated with the occurrence of somatization symptoms in patients with major depression.

METHOD

Somatization was evaluated using the respective subscale of the Symptom Checklist SCL-90-R. Six monoaminergic genes were identified showing an involvement in pain perception and somatization according to the literature: COMT, HTR2A, SLC6A2, SLC6A4, DRD4, and TPH1. One hundred and eighteen single nucleotide polymorphisms (SNPs) within these genes were genotyped using Illumina BeadChips in a sample of 398 at least moderately to severely depressed in-patients participating in the Munich Antidepressant Response Signature (MARS) project.

RESULTS

Thirty SNPs exhibit nominally significant associations with somatization. One SNP (rs9534505) located in intron 2 of the HTR2A gene withstood correction for multiple testing. Clinical data provide further evidence for strong impact of somatization on the presentation of depressive symptoms and description of a patient subgroup with unfavorable clinical outcome.

CONCLUSION

Our results demonstrate the influence of a HTR2A polymorphism on aspects of somatization in major depression, which co-occurs with an unfavorable antidepressant treatment outcome. These results confirm and expand previous findings on somatization as a risk factor for treatment outcome in major depression.

Functional somatic complaints in depression: An overview

Depression is a disorder of major public health importance which often manifests through functional somatic complaints. Concept of functional somatic complaints dates back to the time of Wernicke and is later substantiated by various authors. Although considered as an alternative 'idiom of distress' in certain culture, functional somatic complaints are universal. Various international, cross-cultural, inpatient and outpatient based studies have reported that about two-third of subjects of depression present to clinicians with functional somatic complaints which often leads to misrecognition of their illness and in turn leads to increased utilization of health services. These functional somatic complaints can be related to various organ systems but show remarkable homogeneity in their presentation across culture. Various instruments have attempted to tap the functional somatic complaints but are limited by their cross-cultural validity. Among important correlates of functional somatic complaints are female gender, severity of depression, subsyndromal anxiety, alexithymia, somatosensory amplification and hypochondriacal worry are to name a few. Neurobiological understanding implicates neurotransmitters serotonin and norepinephrine, resultantly Serotonin Norepinephrine Reuptake Inhibitors have been found to be effective in treating functional somatic complaints in depression. Future revisions in the nosological systems should consider giving proper importance to some of these symptoms for diagnosing depression.

A genome-wide association study of neuroticism in a population-based sample

Neuroticism is a moderately heritable personality trait considered to be a risk factor for developing major depression, anxiety disorders and dementia. We performed a genome-wide association study in 2,235 participants drawn from a population-based study of neuroticism, making this the largest association study for neuroticism to date. Neuroticism was measured by the Eysenck Personality Questionnaire. After Quality Control, we analysed 430,000 autosomal SNPs together with an additional 1.2 million SNPs imputed with high quality from the Hap Map CEU samples. We found a very small effect of population stratification, corrected using one principal component, and some cryptic kinship that required no correction. NKAIN2 showed suggestive evidence of association with neuroticism as a main effect (p<10⁻⁶) and GPC6 showed suggestive evidence for interaction with age (p≈10⁻⁷). We found support for one previously-reported association (PDE4D), but failed to replicate other recent reports. These results suggest common SNP variation does not strongly influence neuroticism. Our study was powered to detect almost all SNPs explaining at least 2% of heritability, and so our results effectively exclude the existence of loci having a major effect on neuroticism.

Bipolar disorder--methodological problems and future perspectives

Since its “rebirth” in 1966, bipolar disorder (BPD) has rapidly come to occupy a central position in the research and treatment of mood disorders. Compared with major depressive disorder (MDD), BPD is a more serious condition, characterized by much more frequent recurrence, more complex comorbidity, and higher mortality. One major problem is the lack of valid definitions in adult and in child psychiatry; the current definitions are unsatisfactory, and heavily favor an overdiagnosis of MDD. Biological research is partially based on those definitions, which have a short half-life. An additional, dimensional, approach, quantifying hypomania, depression, and anxiety by self-assessment and symptom checklists is recommended, A further, related problem is the early recognition of the onset of BPD, especially in adolescence, and the identification of correlates in childhood. Early and timely diagnosis of BPD is necessary to enable prompt intervention and secondary prevention of the disorder. The paper describes the current status and future directions of developing clinical concepts of bipolarity

Personality traits in unaffected twins discordant for affective disorder

OBJECTIVE

To examine whether a high genetic liability to develop affective disorder is associated with specific personality traits.

METHOD

A cross-sectional, high-risk, case-control study. Through nation-wide registers, healthy monozygotic (MZ) and dizygotic (DZ) twins with (high-risk twins) and without (the control group/low-risk twins) a co-twin history of affective disorder were identified. Personality traits were compared for a total of 211 high-risk and low-risk twins.

RESULTS

In univariate analyses, the high-risk twins had a higher level of neuroticism than the control twins (P = 0.03). In multivariate analyses, a high genetic liability to affective disorder was not significantly associated with neuroticism but correlated to sex, minor psychopathology and recent life events.

CONCLUSION

A high genetic liability to affective disorder showed an association with neuroticism, but the association interacts with other predictors of affective disorder such as female gender, minor psychopathology and recent adversity.

Subclinical psychopathology and socio-economic status in unaffected twins discordant for affective disorder

BACKGROUND

The most potent risk factor for affective disorders is a family history of affective disorder but the specific factors that are transmitted in families are unknown. It is possible to investigate the relation between risk factors and affective disorder by using a high-risk design e.g.: a study of the healthy relatives of patients with affective disorders.

AIM

To compare psychopathology and socio-economic status between twins with a co-twin history of affective disorder and twins without.

METHODS

In a cross-sectional high-risk case-control study, healthy monozygotic and dizygotic twins with (High-Risk twins) and without (Low-Risk twins) a co-twin history of affective disorder were identified through nation-wide registers. Participants were assessed using semi-structured psychiatric interviews and self-rating of psychopathology.

RESULTS

High-Risk twins had a lower education level, a lower work position and tendency towards being more often unemployed and early retired than the Low-Risk twins. Furthermore, they presented higher rates of subclinical affective symptoms and were more likely to experience a minor psychiatric diagnosis.

CONCLUSION

Healthy twins with a high genetic liability to affective disorder seem to present lower socio-economic status, higher rates of subclinical affective symptoms and more often experience a minor psychiatric diagnosis than twins with no familial history of affective disorder. It is not possible from the present cross-sectional data to determine the causality of these findings, thus genetic liability to affective disorder, socio-economic status and minor psychopathology seem to have a complex interrelation.

Minor depression as a predictor of the first onset of major depressive disorder over a 15-year follow-up

OBJECTIVE

To study the relationship of minor depression to first onset of major depressive disorder (MDD) among 1634 individuals over a 15-year follow-up using the Baltimore Epidemiologic Catchment Area cohort.

METHOD

Logistic regression analyses were conducted with minor depression alone and also adjusting for anxiety, sociodemographic, and medical variables, with MDD as the outcome variable. Also, among those with minor depression, depressive symptom categories were studied with both logistic regression and population attributable risk (PAR) to determine if they predicted MDD.

RESULTS

Individuals with a history of minor depression had an odds ratio of more than 5 of having a first lifetime episode of MDD (adjusted OR: 5.37, 95% CI: 2.87, 10.06). Suicidal ideation, appetite/weight issues, and sleep difficulty had the highest PARs.

CONCLUSION

Minor depression strongly predicts MDD. Clinical and public health interventions for individuals with minor depression can potentially impact the pathway leading to MDD.

Do personality traits predict first onset in depressive and bipolar disorder?

The aim was to investigate whether personality traits predict onset of the first depressive or manic episode (the vulnerability hypothesis) and whether personality might be altered by the mood disorder (the scar hypothesis). A systematic review of population-based and high-risk studies concerning personality traits and affective disorder in adults was conducted. Nine cross-sectional high-risk studies, seven longitudinal high-risk studies and nine longitudinal population-based studies were found. Most studies support the vulnerability hypothesis and there is evidence that neuroticism is a premorbid risk factor for developing depressive disorder. The evidence for the scar hypothesis is sparse, but the studies with the strongest design showed evidence for both hypotheses. Only few studies of bipolar disorder were found and the association between personality traits and bipolar disorder is unclear. Neuroticism seem to be a risk factor by which vulnerable individuals can be identified, thus preventing the development of depressive disorder. A connection between personality traits and development of bipolar disorder, and evidence of a personality-changing effect of affective episodes need to be further investigated.

The level of recognition of physical symptoms in patients with a major depression episode in the outpatient psychiatric practice in Puerto Rico: an observational study

BACKGROUND

This study was designed to evaluate the psychiatrists' level of recognition of somatic symptoms associated to a major depressive episode (MDE) (DSM-IV-TR criteria) and the impact of those somatic symptoms on the treatment effectiveness.

METHODS

This non-interventional study was conducted in 25 medical offices in Puerto Rico from February to December 2003. It had 2 visits separated by 8 weeks. The level of recognition was determined by: the correlation between the physician clinical evaluation and their patients' self-evaluations through different validated instruments using kappa statistics. Chi-square test was used to evaluate the impact of somatic symptoms on treatment antidepressants' effectiveness.

RESULTS

All the 145 recruited patients reported the presence of at least one somatic symptom associated with their current MDE. In the two visits covered by the study, a fair agreement between the psychiatrists' and the patients' reports was noted for headache, abdominal pain and upper limb pains (0.4003 <or= kappa >or= 0.6594). For other painful symptoms and painless somatic symptoms, the Kappa values obtained were non-significant. Slight but significant reductions in depression and painful symptoms severity were observed after 8 weeks of treatment. A proportional relationship between the pain and depression severity was observed (p < 0.0001).

CONCLUSION

The study results show that somatic symptoms: are very common in depressed Puerto Rican patients; are significant under-reported by psychiatrists; and have a significant impact on the antidepressant effectiveness.

The Munich vulnerability study on affective disorders: premorbid neuroendocrine profile of affected high-risk probands

One of the most characteristic alterations in depression is a disturbed regulation of the hypothalamic-pituitary-adrenocortical (HPA) system. A function test combining the pre-treatment of 1.5 mg dexamethasone (DEX) with a challenge of 100 microg corticotropin-releasing hormone (CRH) reveals a pathological increase in the adrenocorticotropin and cortisol release in patients with major depression. These changes partially persist after successful treatment with remission and therefore, might represent trait or vulnerability markers. To further address this question, we were investigating the premorbid neuroendocrine profile of 74 healthy high-risk probands (HRPs) with a positive family history for affective disorders. The aim was to identify premorbid vulnerability factors. During the observation period, 19 HRPs developed an affective disorder. Their premorbid DEX/CRH test results were compared with 19 age- and sex matched controls. No significant differences could be observed between these two groups. Our results suggest that a dysregulated HPA system indicated by this function test can rather be regarded as a neurobiological scar developing during the course of affective disorders.