The ZInEP Epidemiology Survey: background, design and methods

Deep Learning in the Identification of Electroencephalogram Sources Associated with Sexual Orientation

INTRODUCTION

It is unclear if sexual orientation is a biological trait that has neurofunctional footprints. With deep learning, the power to classify biological datasets without an a priori selection of features has increased by magnitudes. The aim of this study was to correctly classify resting-state electroencephalogram (EEG) data from males with different sexual orientation using deep learning and to explore techniques to identify the learned distinguishing features.

METHODS

Three cohorts (homosexual men, heterosexual men, and a mixed sex cohort), one pretrained network on sex classification, and one newly trained network for sexual orientation classification were used to classify sex. Further, Grad-CAM methodology and source localization were used to identify the spatiotemporal patterns that were used for differentiation by the networks.

RESULTS

Using a pretrained network for classification of males and females, no differences existed between classification of homosexual and heterosexual males. The newly trained network was able, however, to correctly classify the cohorts with a total accuracy of 83%. The retrograde activation using Grad-CAM technology yielded distinctive functional EEG patterns in the Brodmann area 40 and 1 when combined with Fourier analysis and a source localization.

DISCUSSION

This study shows that electrophysiological trait markers of male sexual orientation can be identified using deep learning. These patterns are different from the differentiating signatures of males and females in a resting-state EEG.

Major depressive disorder subtypes and depression symptoms in multiple sclerosis: What is different compared to the general population?

OBJECTIVE

To compare and characterize major depressive disorder (MDD) subtypes (i.e., pure atypical, pure melancholic and mixed atypical-melancholic) and depression symptoms in persons with multiple sclerosis (PwMS) with persons without MS (Pw/oMS) fulfilling the DSM-5 criteria for a past 12-month MDD.

METHODS

MDD in PwMS (n = 92) from the Swiss Multiple Sclerosis Registry was compared with Pw/oMS (n = 277) from a Swiss community-based study. Epidemiological MDD diagnoses were based on the Mini-SPIKE (shortened form of the Structured Psychopathological Interview and Rating of the Social Consequences for Epidemiology). Logistic and multinomial regression analyses (adjusted for sex, age, civil status, depression and severity) were computed for comparisons and characterization. Latent class analysis (LCA) was conducted to empirically identify depression subtypes in PwMS.

RESULTS

PwMS had a higher risk for the mixed atypical-melancholic MDD subtype (OR = 2.22, 95% CI = 1.03-4.80) compared to Pw/oMS. MDD in PwMS was specifically characterized by a higher risk of the two somatic atypical depression symptoms 'weight gain' (OR = 6.91, 95% CI = 2.20-21.70) and 'leaden paralysis' (OR = 3.03, 95% CI = 1.35-6.82) and the symptom 'irritable/angry' (OR = 3.18, 95% CI = 1.08-9.39).

CONCLUSIONS

MDD in PwMS was characterized by a higher risk for specific somatic atypical depression symptoms and the mixed atypical-melancholic MDD subtype. The pure atypical MDD subtype, however, did not differentiate between PwMS and Pw/oMS. Given the high phenomenological overlap with MS symptoms, the mixed atypical-melancholic MDD subtype represents a particular diagnostic challenge.

Differences between unipolar mania and bipolar-I disorder: Evidence from nine epidemiological studies

OBJECTIVES

Although clinical evidence suggests important differences between unipolar mania and bipolar-I disorder (BP-I), epidemiological data are limited. Combining data from nine population-based studies, we compared subjects with mania (M) or mania with mild depression (Md) to those with BP-I with both manic and depressive episodes with respect to demographic and clinical characteristics in order to highlight differences.

METHODS

Participants were compared for gender, age, age at onset of mania, psychiatric comorbidity, temperament, and family history of mental disorders. Generalized linear mixed models with adjustment for sex and age as well as for each study source were applied. Analyses were performed for the pooled adult and adolescent samples, separately.

RESULTS

Within the included cohorts, 109 adults and 195 adolescents were diagnosed with M/Md and 323 adults and 182 adolescents with BP-I. In both adult and adolescent samples, there was a male preponderance in M/Md, whereas lifetime generalized anxiety and/panic disorders and suicide attempts were less common in M/Md than in BP-I. Furthermore, adults with mania revealed bulimia/binge eating and drug use disorders less frequently than those with BP-I.

CONCLUSIONS

The significant differences found in gender and comorbidity between mania and BP-I suggest that unipolar mania, despite its low prevalence, should be established as a separate diagnosis both for clinical and research purposes. In clinical settings, the rarer occurrence of suicide attempts, anxiety, and drug use disorders among individuals with unipolar mania may facilitate successful treatment of the disorder and lead to a more favorable course than that of BP-I disorder.

The Swiss Multiple Sclerosis Registry (SMSR): study protocol of a participatory, nationwide registry to promote epidemiological and patient-centered MS research

Background

Multiple sclerosis (MS) is one of the most frequently observed neurological conditions in Switzerland, but data sources for country-wide epidemiological trend monitoring are lacking. Moreover, while clinical and laboratory MS research are generally well established, there is a gap in patient-centered MS research to inform care management, or treatment decisions and policy making not only in Switzerland but worldwide.

Methods

In light of these research gaps, the Swiss Multiple Sclerosis Society initiated and funded the Swiss Multiple Sclerosis Registry (SMSR) an open-ended, longitudinal and prospective, nationwide, patient-centered study.

The SMSR recruits adult persons with a suspected or confirmed MS diagnosis who reside or receive care in Switzerland. The SMSR has established a governance structure with clear rules and guidelines. It follows a citizen-science approach with direct involvement of persons with MS (PwMS), who contribute actively to registry development, operations, and research. Main scientific goals entail the study of MS epidemiology in Switzerland, health care access and provision, as well as life circumstances and wellbeing of persons with MS.

The innovative study design (“layer model”) offers several participation options with different time commitments. Data collection is by means of regular surveys and medical record abstraction. Survey participation is offered in different modes (web, paper & pencil) and in the three main national languages (German, French, Italian). Participants also receive regular data feedbacks for personal use and self-monitoring, contextualized in the whole population of study participants. Data feedbacks are also used to solicit data corrections of key variables from participants.

Discussion

The SMSR combines the advantages of traditional and novel research methods in medical research and has recruited over 1600 PwMS in its first year. The future-oriented design and technology will enable a response not only to future technological innovations and research trends, but also to challenges in health care provision for MS.

Trial registration

ClinicalTrials.gov NCT02980640; December 6, 2016; retrospectively registered.

Subtypes of stuttering determined by latent class analysis in two Swiss epidemiological surveys

Aims

Associations between stuttering in childhood and a broad spectrum of risk factors, associated factors and comorbidities were examined in two large epidemiological studies. Subtypes of stuttering were then identified based on latent class analysis (LCA).

Methods

Data were from two representative Swiss population samples: PsyCoLaus (N = 4,874, age 35–82 years) and the ZInEP Epidemiology Survey (N = 1,500, age 20–41 years). Associations between stuttering and sociodemographic characteristics, familial aggregation, comorbidity and psychosocial risk / associated factors were investigated in both samples. LCAs were conducted on selected items from people in both samples who reported having stuttered in childhood.

Results

Initial analyses linked early anxiety disorders, such as separation anxiety disorder and overanxious disorder, to stuttering (PsyCoLaus). ADHD was associated with stuttering in both datasets. In the analyses of risk / associated factors, dysfunctional parental relationships, inter-parental violence and further childhood adversities were mutual predictors of stuttering. Moreover, comorbidities were seen with hay fever, asthma, eczema and psoriasis (PsyCoLaus). Subsequent LCA identified an unspecific group of persons who self-reported that they stuttered and a group defined by associations with psychosocial adversities (ZINEP, PsyCoLaus) and atopic diseases (PsyCoLaus).

Conclusions

The two subtypes of developmental stuttering have different risk / associated factors and comorbidity patterns. Most of the factors are associated with vulnerability mechanisms that occur early in life and that have also been linked with other neurodevelopmental disorders. Both psychosocial and biological factors appear to be involved in the etiopathogenesis of stuttering.

Sleep disturbances in young and middle-aged adults - Empirical patterns and related factors from an epidemiological survey

BACKGROUND

Previous research suggests that sleep disorders are highly associated with other mental health problems. However, sleep problems even below the diagnostic threshold of sleep disorders are very common in the general population, which highly affects wellbeing and functioning. In order to broaden the focus beyond those severe cases we explored empirical patterns across the whole spectrum of sleep problems as well as associated clinical and other factors.

METHOD

A representative community sample of N=1274 residents from the canton of Zurich was interviewed for sleep problems and diagnostic criteria for mental disorders as well as was given a number of mental health-related psychometrical checklists. Based on a broader spectrum of sleep problems we conducted a latent class analysis (LCA) to derive distinct classes of such disturbances. Classes were compared regarding their associations to mental health-relevant and other risk factors.

RESULTS

The LCA revealed four classes - no sleep disturbances (72.6%), difficulties initiating and maintaining sleep (15.8%), delayed sleep (5.3%), and severe sleep problems (6.4%). Severe sleep problems were related to female gender and generalized anxiety disorder, while depression was linked to all sleep problem classes. Persons with difficulties initiating and maintaining sleep and severe sleep problems reported higher levels of psychopathology, burnout and neuroticism, while all sleep problem types were tied to stress-related variables, but not alcohol use disorder.

DISCUSSION

Sleep problems are highly prevalent among the young and middle-aged adults in our representative sample of young and middle-aged adults and as such represent a serious public mental health problem. Our findings indicate sleep problems to have a multi-dimensional structure with some differential associations. While all subtypes were associated with poorer mental health and particularly more depression, severe sleep problems appeared to be the sleep subtype seen in agoraphobia and GAD, while delayed sleep had no specific associations. The variety of associations assessed leads one to assume that likewise a variety of sleep interventions is required.

Stigma-related stress, shame and avoidant coping reactions among members of the general population with elevated symptom levels

BACKGROUND

It is unclear whether mental illness stigma affects individuals with subthreshold syndromes outside clinical settings. We therefore investigated the role of different stigma variables, including stigma-related stress and shame reactions, for avoidant stigma coping among members of the general population with elevated symptom levels.

METHODS

Based on a representative population survey, general stress resilience, stigma variables, shame about having a mental illness as well as avoidant stigma coping (secrecy and social withdrawal) were assessed by self-report among 676 participants with elevated symptom levels. Stigma variables and resilience were examined as predictors of avoidant stigma coping in a path model.

RESULTS

Increased stigma stress was predicted by lower general stress resilience as well as by higher levels of perceived stigma, group identification and perceived legitimacy of discrimination. More shame was associated with higher perceived legitimacy. Lower resilience as well as more perceived stigma, group identification and perceived legitimacy predicted avoidant coping. Stigma stress partly mediated effects of resilience, perceived stigma and group identification on avoidant coping; shame partly mediated effects of perceived legitimacy on coping. Stigma stress and shame were also directly and positively related to avoidant stigma coping. Analyses were adjusted for symptoms, neuroticism and sociodemographic variables.

CONCLUSIONS

Stigma may affect a larger proportion of the population than previously thought because stigma variables predicted secrecy and withdrawal among members of the general population with elevated, but overall mild symptom levels. Avoidant stigma coping likely has harmful effects, potentially exacerbating pre-existing psychological distress and undermining social networks. This highlights the need to reduce public stigma as well as to support individuals with subthreshold syndromes in their coping with stigma stress and shame reactions.

Mental illness stigma, secrecy and suicidal ideation

AIMS

Whether the public stigma associated with mental illness negatively affects an individual, largely depends on whether the person has been labelled 'mentally ill'. For labelled individuals concealing mental illness is a common strategy to cope with mental illness stigma, despite secrecy's potential negative consequences. In addition, initial evidence points to a link between stigma and suicidality, but quantitative data from community samples are lacking.

METHODS

Based on previous literature about mental illness stigma and suicidality, as well as about the potential influence of labelling processes and secrecy, a theory-driven model linking perceived mental illness stigma and suicidal ideation by a mediation of secrecy and hopelessness was established. This model was tested separately among labelled and unlabelled persons using data derived from a Swiss cross-sectional population-based study. A large community sample of people with elevated psychiatric symptoms was examined by interviews and self-report, collecting information on perceived stigma, secrecy, hopelessness and suicidal ideation. Participants who had ever used mental health services were considered as labelled 'mentally ill'. A descriptive analysis, stratified logistic regression models and a path analysis testing a three-path mediation effect were conducted.

RESULTS

While no significant differences between labelled and unlabelled participants were observed regarding perceived stigma and secrecy, labelled individuals reported significantly higher frequencies of suicidal ideation and feelings of hopelessness. More perceived stigma was associated with suicidal ideation among labelled, but not among unlabelled individuals. In the path analysis, this link was mediated by increased secrecy and hopelessness.

CONCLUSIONS

Results from this study indicate that among persons labelled 'mentally ill', mental illness stigma is a contributor to suicidal ideation. One explanation for this association is the relation perceived stigma has with secrecy, which introduces negative emotional consequences. If our findings are replicated, they would suggest that programmes empowering people in treatment for mental illness to cope with anticipated and experienced discrimination as well as interventions to reduce public stigma within society could improve suicide prevention.

Distribution of Response Time, Cortical, and Cardiac Correlates during Emotional Interference in Persons with Subclinical Psychotic Symptoms

A psychosis phenotype can be observed below the threshold of clinical detection. The study aimed to investigate whether subclinical psychotic symptoms are associated with deficits in controlling emotional interference, and whether cortical brain and cardiac correlates of these deficits can be detected using functional near-infrared spectroscopy (fNIRS). A data set derived from a community sample was obtained from the Zurich Program for Sustainable Development of Mental Health Services. 174 subjects (mean age 29.67 ± 6.41, 91 females) were assigned to four groups ranging from low to high levels of subclinical psychotic symptoms (derived from the Symptom Checklist-90-R). Emotional interference was assessed using the emotional Stroop task comprising neutral, positive, and negative conditions. Statistical distributional methods based on delta plots [behavioral response time (RT) data] and quantile analysis (fNIRS data) were applied to evaluate the emotional interference effects. Results showed that both interference effects and disorder-specific (i.e., group-specific) effects could be detected, based on behavioral RTs, cortical hemodynamic signals (brain correlates), and heart rate variability (cardiac correlates). Subjects with high compared to low subclinical psychotic symptoms revealed significantly reduced amplitudes in dorsolateral prefrontal cortices (interference effect, p < 0.001) and middle temporal gyrus (disorder-specific group effect, p < 0.001), supported by behavioral and heart rate results. The present findings indicate that distributional analyses methods can support the detection of emotional interference effects in the emotional Stroop. The results suggested that subjects with high subclinical psychosis exhibit enhanced emotional interference effects. Based on these observations, subclinical psychosis may therefore prove to represent a valid extension of the clinical psychosis phenotype.

Pure animal phobia is more specific than other specific phobias: epidemiological evidence from the Zurich Study, the ZInEP and the PsyCoLaus

Interest in subtypes of mental disorders is growing in parallel with continuing research progress in psychiatry. The aim of this study was to examine pure animal phobia in contrast to other specific phobias and a mixed subtype. Data from three representative Swiss community samples were analysed: PsyCoLaus (n = 3720), the ZInEP Epidemiology Survey (n = 1500) and the Zurich Study (n = 591). Pure animal phobia and mixed animal/other specific phobias consistently displayed a low age at onset of first symptoms (8-12 years) and clear preponderance of females (OR > 3). Meanwhile, other specific phobias started up to 10 years later and displayed almost a balanced sex ratio. Pure animal phobia showed no associations with any included risk factors and comorbid disorders, in contrast to numerous associations found in the mixed subtype and in other specific phobias. Across the whole range of epidemiological parameters examined in three different samples, pure animal phobia seems to represent a different entity compared to other specific phobias. The etiopathogenetic mechanisms and risk factors associated with pure animal phobias appear less clear than ever.

Big Five personality traits may inform public health policy and preventive medicine: Evidence from a cross-sectional and a prospective longitudinal epidemiologic study in a Swiss community

BACKGROUND

Some evidence documents the importance of personality assessments for health research and practise. However, no study has opted to test whether a short self-report personality inventory may comprehensively inform health policy.

METHODS

Data were taken from a population-based epidemiologic survey in Zurich, Switzerland, conducted from 2010-2012. A short form of the Big Five Inventory was completed by n=1155 participants (54.4% women; mean age=29.6 years), while health-related outcomes were taken from a comprehensive semi-structured clinical interview. A convenience subsample averaging n=171 participants additionally provided laboratory measures and n=133 were subsequently followed-up at least once over a maximal period of 6 months.

RESULTS

Personality traits, in particular high neuroticism and low conscientiousness, related significantly to poor environmental resources such as low social support (R(2)=0.071), health-impairing behaviours such as cannabis use (R(2)=0.071), and psychopathology, including negative affect (R(2)=0.269) and various mental disorders (R(2)=0.060-0.195). The proportion of total variance explained was R(2)=0.339 in persons with three or more mental disorders. Personality significantly related to some laboratory measures including total cholesterol (R(2)=0.095) and C-Reactive Protein (R(2)=0.062). Finally, personality prospectively predicted global psychopathological distress and vegetative symptoms over a 6-month observation period.

CONCLUSIONS

Personality relates consistently to poor socio-environmental resources, health-impairing behaviours and psychopathology. We also found some evidence for an association with metabolic and immune functions that are assumed to influence health. A short personality inventory could provide valuable information for preventive medicine when used as a means to screen entire populations for distinct risk exposure, in particular with respect to psychopathology.

Childhood trauma as a risk factor for the onset of subclinical psychotic experiences: Exploring the mediating effect of stress sensitivity in a cross-sectional epidemiological community study

Childhood trauma is a risk factor for the onset of schizophrenic psychosis. Because the psychosis phenotype can be described as a continuum with varying levels of severity and persistence, childhood trauma might likewise increase the risk for psychotic experiences below the diagnostic threshold. But the impact of stressful experiences depends upon its subjective appraisal. Therefore, varying degrees of stress sensitivity possibly mediate how childhood trauma impacts in the end upon the occurrence of subclinical psychotic experiences. We investigated this research question in a representative community cohort of 1500 participants. A questionnaire, comprising five domains of physical and emotional neglect, as well as physical, emotional, and sexual abuse, was used to assess childhood trauma. Based on different symptoms of subclinical psychotic experiences, we conducted a latent profile analysis (LPA) to derive distinct profiles for such experiences. Path modeling was performed to identify the direct and indirect (via stress sensitivity) pathways from childhood trauma to subclinical psychotic experiences. The LPA revealed four classes - unaffected, anomalous perceptions, odd beliefs and behavior, and combined anomalous perceptions/odd beliefs and behavior, that - except for sexual abuse - were all linked to childhood trauma. Moreover, except for physical abuse, childhood trauma was significantly associated with stress sensitivity. Thus, our results revealed that the pathways from emotional neglect/abuse and physical neglect to subclinical psychotic experiences were mediated by stress sensitivity. In conclusion, we can state that subclinical psychotic experiences are affected by childhood traumatic experiences in particular through the pathway of a heightened subjective stress appraisal.

Mental Health Literacy, Attitudes to Help Seeking, and Perceived Need as Predictors of Mental Health Service Use: A Longitudinal Study

Many people with mental health problems do not use mental health care, resulting in poorer clinical and social outcomes. Reasons for low service use rates are still incompletely understood. In this longitudinal, population-based study, we investigated the influence of mental health literacy, attitudes toward mental health services, and perceived need for treatment at baseline on actual service use during a 6-month follow-up period, controlling for sociodemographic variables, symptom level, and a history of lifetime mental health service use. Positive attitudes to mental health care, higher mental health literacy, and more perceived need at baseline significantly predicted use of psychotherapy during the follow-up period. Greater perceived need for treatment and better literacy at baseline were predictive of taking psychiatric medication during the following 6 months. Our findings suggest that mental health literacy, attitudes to treatment, and perceived need may be targets for interventions to increase mental health service use.

Mismatch negativity: Alterations in adults from the general population who report subclinical psychotic symptoms

BACKGROUND

Deficits of mismatch negativity (MMN) in schizophrenia and individuals at risk for psychosis have been replicated many times. Several studies have also demonstrated the occurrence of subclinical psychotic symptoms within the general population. However, none has yet investigated MMN in individuals from the general population who report subclinical psychotic symptoms.

METHODS

The MMN to duration-, frequency-, and intensity deviants was recorded in 217 nonclinical individuals classified into a control group (n=72) and three subclinical groups: paranoid (n=44), psychotic (n=51), and mixed paranoid-psychotic (n=50). Amplitudes of MMN at frontocentral electrodes were referenced to average. Based on a three-source model of MMN generation, we conducted an MMN source analysis and compared the amplitudes of surface electrodes and sources among groups.

RESULTS

We found no significant differences in MMN amplitudes of surface electrodes. However, significant differences in MMN generation among the four groups were revealed at the frontal source for duration-deviant stimuli (P=0.01). We also detected a trend-level difference (P=0.05) in MMN activity among those groups for frequency deviants at the frontal source.

CONCLUSIONS

Individuals from the general population who report psychotic symptoms are a heterogeneous group. However, alterations exist in their frontal MMN activity. This increased activity might be an indicator of more sensitive perception regarding changes in the environment for individuals with subclinical psychotic symptoms.

Comparing two basic subtypes in OCD across three large community samples: a pure compulsive versus a mixed obsessive-compulsive subtype

Due to its heterogeneous phenomenology, obsessive-compulsive disorder (OCD) has been subtyped. However, these subtypes are not mutually exclusive. This study presents an alternative subtyping approach by deriving non-overlapping OCD subtypes. A pure compulsive and a mixed obsessive-compulsive subtype (including subjects manifesting obsessions with/without compulsions) were analyzed with respect to a broad pattern of psychosocial risk factors and comorbid syndromes/diagnoses in three representative Swiss community samples: the Zurich Study (n = 591), the ZInEP sample (n = 1500), and the PsyCoLaus sample (n = 3720). A selection of comorbidities was examined in a pooled database. Odds ratios were derived from logistic regressions and, in the analysis of pooled data, multilevel models. The pure compulsive subtype showed a lower age of onset and was characterized by few associations with psychosocial risk factors. The higher social popularity of the pure compulsive subjects and their families was remarkable. Comorbidities within the pure compulsive subtype were mainly restricted to phobias. In contrast, the mixed obsessive-compulsive subtype had a higher prevalence and was associated with various childhood adversities, more familial burden, and numerous comorbid disorders, including disorders characterized by high impulsivity. The current comparison study across three representative community surveys presented two basic, distinct OCD subtypes associated with differing psychosocial impairment. Such highly specific subtypes offer the opportunity to learn about pathophysiological mechanisms specifically involved in OCD.

Brain correlates of verbal fluency in subthreshold psychosis assessed by functional near-infrared spectroscopy

The prevalence of subthreshold psychotic symptoms in the general population has gained increasing interest as a possible precursor of psychotic disorders. The goal of the present study was to evaluate whether neurobiological features of subthreshold psychotic symptoms can be detected using verbal fluency tasks and functional near-infrared spectroscopy (fNIRS). A large data set was obtained from the Zurich Program for Sustainable Development of Mental Health Services (ZInEP). Based on the SCL-90-R subscales 'Paranoid Ideation' and 'Psychoticism' a total sample of 188 subjects was assigned to four groups with different levels of subthreshold psychotic symptoms. All subjects completed a phonemic and semantic verbal fluency task while fNIRS was recorded over the prefrontal and temporal cortices. Results revealed larger hemodynamic (oxy-hemoglobin) responses to the phonemic and semantic conditions compared to the control condition over prefrontal and temporal cortices. Subjects with high subthreshold psychotic symptoms exhibited significantly reduced hemodynamic responses in both conditions compared to the control group. Further, connectivity between prefrontal and temporal cortices revealed significantly weaker patterns in subjects with high subthreshold psychotic symptoms compared to the control group, possibly indicating less incisive network connections associated with subthreshold psychotic symptoms. The present findings provide evidence that subthreshold forms of psychotic symptoms are associated with reduced hemodynamic responses and connectivity in prefrontal and temporal cortices during verbal fluency that can be identified using fNIRS.

Predicting perceived need for mental health care in a community sample: an application of the self-regulatory model

PURPOSE

Most people with mental health problems do not use mental health services, resulting in poor psychiatric outcomes and greater illness burden. Although perceiving the need for mental health care was identified to be a key factor for service use, factors that explain differences in perceived need for mental health care are incompletely understood. The present paper investigates the role of illness representations in predicting perceived need for mental health care.

METHODS

In a community sample of 202 persons currently distressed by symptoms related to mental illness, illness representations were assessed using the Brief Illness Perception Questionnaire and perceived need for mental health care was measured by the Self-Appraisal of Illness Questionnaire. Multiple linear regression models were used to determine the association between a person's illness representations and the level of perceived need for mental health care.

RESULTS

Two illness representations were positively associated with perceived need for mental health care: the belief that treatment could improve the current mental health problem and the attribution of experienced symptoms to a mental health problem. Increased perceived need for care was related to current mental health service use.

CONCLUSIONS

Interventions that aim to increase mental health service use could focus on people's attitudes toward mental health treatment and enable people to recognize symptoms as a mental illness.

Association between processing speed and subclinical psychotic symptoms in the general population: focusing on sex differences

Evidence is growing that persons along the schizophrenia spectrum, i.e., those who also display subclinical psychotic symptoms, exhibit deficits across a broad range of neuropsychological domains. Because sex differences in the association between cognitive deficits and psychosis have thus far been mostly neglected, we believe that ours is the first study specifically focused upon those differences when examining the relationship between subclinical psychosis and processing speed. Using a sample of 213 persons from the general population from Zurich, Switzerland, psychotic symptoms were assessed with three different questionnaires including the Schizotypal Personality Questionnaire, an adaptation of the Structured Interview for Assessing Perceptual Anomalies, and the Paranoia Checklist. Processing speed was assessed with the WAIS digit-symbol coding test. Two higher-order psychosis domains were factor-analytically derived from the various psychosis subscales and then subjected to a series of linear regression analyses. The results demonstrate that in both men and women associations between subclinical psychosis domains and processing speed were weak to moderate (β ranging from -0.18 to -0.27; all p<0.05). However, we found no sex-differences in the interrelation of subclinical psychosis and processing speed (ΔR(2)<0.005; p>0.30). In conclusion, it appears that sex differences in psychosis manifest themselves only at the high end of the continuum (full-blown schizophrenia) and not across the sub-threshold range. The small magnitude of the effects reported herein conforms to the etiopathology of the disorder. Since schizophrenia and related disorders from the spectrum are assumed to be multifactorial diseases, it follows that many etiological components of small effect are involved.

Serum testosterone levels and symptom-based depression subtypes in men

The main objective of this preliminary study was to further clarify the association between testosterone (T) levels and depression by investigating symptom-based depression subtypes in a sample of 64 men. The data were taken from the ZInEP epidemiology survey. Gonadal hormones of a melancholic (n  = 25) and an atypical (n = 14) depression subtype, derived from latent class analysis, were compared with those of healthy controls (n  = 18). Serum T was assayed using an enzyme-linked immunosorbent assay procedure. Analysis of variance, analysis of covariance, non-parametrical tests, and generalized linear regression models were performed to examine group differences. The atypical depressive subtype showed significantly lower T levels compared with the melancholic depressives. While accumulative evidence indicates that, beyond psychosocial characteristics, the melancholic and atypical depressive subtypes are also distinguishable by biological correlates, the current study expanded this knowledge to include gonadal hormones. Further longitudinal research is warranted to disclose causality by linking the multiple processes in pathogenesis of depression.

The ZInEP Epidemiology Survey: background, design and methods

This article introduces the design, sampling, field procedures and instruments used in the ZInEP Epidemiology Survey. This survey is one of six ZInEP projects (Zürcher Impulsprogramm zur nachhaltigen Entwicklung der Psychiatrie, i.e. the "Zurich Program for Sustainable Development of Mental Health Services"). It parallels the longitudinal Zurich Study with a sample comparable in age and gender, and with similar methodology, including identical instruments. Thus, it is aimed at assessing the change of prevalence rates of common mental disorders and the use of professional help and psychiatric sevices. Moreover, the current survey widens the spectrum of topics by including sociopsychiatric questionnaires on stigma, stress related biological measures such as load and cortisol levels, electroencephalographic (EEG) and near-infrared spectroscopy (NIRS) examinations with various paradigms, and sociophysiological tests. The structure of the ZInEP Epidemiology Survey entails four subprojects: a short telephone screening using the SCL-27 (n of nearly 10,000), a comprehensive face-to-face interview based on the SPIKE (Structured Psychopathological Interview and Rating of the Social Consequences for Epidemiology: the main instrument of the Zurich Study) with a stratified sample (n = 1500), tests in the Center for Neurophysiology and Sociophysiology (n = 227), and a prospective study with up to three follow-up interviews and further measures (n = 157). In sum, the four subprojects of the ZInEP Epidemiology Survey deliver a large interdisciplinary database.

An integrative examination of general personality dysfunction in a large community sample

Recently, the severity of general personality dysfunction has gained broad interest in personality disorder (PD) research. We analysed data of 511 participants aged 20-41 years from a comprehensive psychiatric survey in the general population of Zurich, Switzerland. We added the trait-scores from all DSM-IV PDs, as assessed by a self-report questionnaire, to provide a measure of general personality dysfunction. Adjusting for the Big Five personality domains as a proxy for stylistic PD elements, this composite PD score exhibited strong associations with neuroticism and schizotypy. General personality dysfunction additionally revealed a moderate detrimental association with psychosocial functioning and a strong effect on coping resources, on heavy drinking and drug use and on most psychopathological syndromes. Of particular interest is the strong association with total psychopathological distress and co-occurrence of multiple disorders, suggesting that increasing PD severity relates to the degree of global impairment independent of specific PD traits. Discussed herein are implications for public mental health policies, classification, conceptualization and treatment of PDs.