Background. As part of a longitudinal study, prevalence findings of DSM-IV disorders are presented for a random sample of 3021 respondents aged 14 to 24, with response rate 71%. Method. Assessment included various subtypes of disorders, subthreshold conditions and disorders that have only rarely been studied in other epidemiological surveys. The computer-assisted Munich-Composite International Diagnostic Interview (M-CIDI) was used to derive DSM-IV diagnoses. Results. Substance disorders were the most frequent (lifetime 17·7%; 12-month 11·4%), with abuse being considerably more frequent than dependence. Other mental disorders had a lifetime prevalence of 27·5% (12-month, 17·5%) with depressive disorders (16·8%) being more frequent than anxiety disorders (14·4%). Eating disorders (3·0%) and threshold somatoform disorders (1·2%) were rare disorders. Subthreshold anxiety and somatoform disorders, however, were more frequent than threshold disorders. Prevalence of disorders was equally high for males and females, although specific disorder prevalence varied significantly by gender. The co-occurrence of disorders (co-morbidity) was substantial and was significantly related to greater reductions in work productivity and increased rates of professional helpseeking behaviour. Conclusions. Findings underline that mental disorders in young adults are frequent and impairing, limiting work and education ability and social interaction. Given the fact that adolescents and young adults are in a key phase of socialization in terms of professional career and interpersonal relationships, our findings indicate a considerable risk potential for an accumulation of complicating factors and future chronicity. This paper is the first report of this ongoing longitudinal study about early developmental conditions of mental disorders.

Epidemiological data on a wide range of mental disorders from community studies conducted in European countries are presented to determine the availability and consistency of prevalence, disability and treatment findings for the EU. Using a stepwise multimethod approach, 27 eligible studies with quite variable designs and methods including over 150,000 subjects from 16 European countries were identified. Prevalence: On the basis of meta-analytic techniques as well as on reanalyses of selected data sets, it is estimated that about 27% (equals 82.7 million; 95% CI: 78.5–87.1) of the adult EU population, 18–65 of age, is or has been affected by at least one mental disorder in the past 12 months. Taking into account the considerable degree of comorbidity (about one third had more than one disorder), the most frequent disorders are anxiety disorders, depressive, somatoform and substance dependence disorders. When taking into account design, sampling and other methodological differences between studies, little evidence seems to exist for considerable cultural or country variation. Disability and treatment: despite very divergent and fairly crude assessment strategies, the available data consistently demonstrate (a) an association of all mental disorders with a considerable disability burden in terms of number of work days lost (WLD) and (b) generally low utilization and treatment rates. Only 26% of all cases had any consultation with professional health care services, a finding suggesting a considerable degree of unmet need. The paper highlights considerable future research needs for coordinated EU studies across all disorders and age groups. As prevalence estimates could not simply be equated with defined treatment needs, such studies should determine the degree of met and unmet needs for services by taking into account severity, disability and comorbidity. These needs are most pronounced for the new EU member states as well as more generally for adolescent and older populations.

Background. General population data were used to study co-morbidities between lifetime social phobia and mood disorders. Methods. Data come from the US National Comorbidity Survey (NCS). Results. Strong associations exist between lifetime social phobia and major depressive disorder (odds ratio 2·9), dysthymia (2·7) and bipolar disorder (5·9). Odds ratios increase in magnitude with number of social fears. Reported age of onset is earlier for social phobia than mood disorders in the vast majority of co-morbid cases. Temporally-primary social phobia predicts subsequent onset of mood disorders, with population attributable risk proportions of 10–15%. Social phobia is also associated with severity and persistence of co-morbid mood disorders. Conclusions. Social phobia is a commonly occurring, chronic and seriously impairing disorder that is seldom treated unless it occurs in conjunction with another co-morbid condition. The adverse consequences of social phobia include increased risk of onset, severity and course of subsequent mood disorders. Early outreach and treatment of primary social phobia might not only reduce the prevalence of this disorder itself, but also the subsequent onset of mood disorders.

Background. The urban environment may increase the risk for psychotic disorder in interaction with pre-existing risk for psychosis, but direct confirmation has been lacking. The hypothesis was examined that the outcome of subclinical expression of psychosis during adolescence, as an indicator of psychosis-proneness, would be worse for those growing up in an urban environment, in terms of having a greater probability of psychosis persistence over a 3·5-year period. Method. A cohort of 918 adolescents from the Early Developmental Stages of Psychopathology Study (EDSP), aged 14–17 years (mean 15·1 years), growing up in contrasting urban and non-urban environments, completed a self-report measure of psychotic symptoms at baseline (Baseline Psychosis) and at first follow-up around 1 year post-baseline (T1). They were again interviewed by trained psychologists for the presence of psychotic symptoms at the second follow-up on average 3·5 years post-baseline (T2). Results. The rate of T2 psychotic symptoms was 14·2% in those exposed to neither Baseline Psychosis nor Urbanicity, 12·1% in those exposed to Urbanicity alone, 14·9% in those exposed to Baseline Psychosis alone and 29·0% in those exposed to both Baseline Psychosis and Urbanicity. The odds ratio (OR) for the combined exposure was 2·46 [95% confidence interval (CI) 1·46–4·14], significantly greater than that expected if Urbanicity and Baseline Psychosis acted independently. Conclusion. These findings support the suggestion that the outcome of the developmental expression of psychosis is worse in urban environments. The environment may impact on risk for psychotic disorder by causing an abnormal persistence of a developmentally common expression of psychotic experiences.

Background. Research suggests that low-grade psychotic experiences in the general population are a common but transitory developmental phenomenon. Using two independent general population samples, the hypothesis was examined that common, non-clinical developmental expression of psychosis may become abnormally persistent when synergistically combined with developmental exposures that may impact on behavioural and neurotransmitter sensitization such as cannabis, trauma and urbanicity. Method. The amount of synergism was estimated from the additive statistical interaction between baseline cannabis use, childhood trauma and urbanicity on the one hand, and baseline psychotic experiences on the other, in predicting 3-year follow-up psychotic experiences, using data from two large, longitudinal, random population samples from the Netherlands [The Netherlands Mental Health Survey and Incidence Study (NEMESIS)] and Germany [The Early Developmental Stages of Psychopathology (EDSP) study]. Results. The 3-year persistence rates of psychotic experiences were low at 26% in NEMESIS and 31% in EDSP. However, persistence rates were progressively higher with greater baseline number of environmental exposures in predicting follow-up psychotic experiences (χ2=6·9, df=1, p=0·009 in NEMESIS and χ2=4·2, df=1, p=0·04 in EDSP). Between 21% and 83% (NEMESIS) and 29% and 51% (EDSP) of the subjects exposed to both environmental exposures and psychotic experiences at baseline had persistence of psychotic experiences at follow-up because of the synergistic action of the two factors. Conclusion. The findings suggest that environmental risks for psychosis act additively, and that the level of environmental risk combines synergistically with non-clinical developmental expression of psychosis to cause abnormal persistence and, eventually, need for care.

Aus der Einleitung: "The authors of the seven meta-structure papers in this issue have to be applauded for their inspiring attempt to suggest and elaborate a new meta-structure of mental disorders consisting of five ‘ clusters ’. At first sight this proposal seems to be considerably simpler than the current diagnostic classifications structure used by DSM-IV-TR (17 categories ; APA, 2000) and, in some parts, more convergent with the ICD-10 (10 categories ; WHO, 1993). Against the background of dissatisfaction expressed with the current diagnostic classification structure for mental disorders and its principles, the authors provide a selective critical review of relevant research. In particular, evidence is examined to address the question of whether current individual mental disorders differ sufficiently from each other and whether the current more fine-graded distinction of specific mental disorders and their grouping in 10 major classes according to ICD-10 and 17 in DSM-IV-TR is justified. To help answer this question, a prioricriteria were chosen in the form of a wide range of ‘validators ’ grouped into so-called ‘causal’ risk factors (i.e. shared genetic risk factors, familiality, shared environmental risks, shared neural substrates, shared biomarkers, shared temperamental antecedents) and factors thought to be more likely to reflect the clinical picture itself (shared abnormalities of cognitive and emotional processing, symptom similarity, rates of co-morbidity, course, treatment response). The results of this impressive exploration are interpreted to suggest a substantial reduction of the current major classes to five clusters and a fairly large residual category of disorders not yet assigned. Particularly noteworthy examples for classificatory changes associated with the proposed meta-structure involve: the suggestion to group anxiety, somatoform and depressive disorders together under the term ‘emotional disorders ’ ; the allocation of bipolar disorders to the ‘psychotic cluster ’ ; and the formation of a broad externalizing cluster that comprises substance use disorders, some of the personality disorders and impulse control disorders. [...]"

Growing up in an urban area has been shown to be associated with an increased risk of psychotic disorder in later life. While it is commonly held that a only a tiny fraction of exposed individuals will develop schizophrenia, recent evidence suggests that expression of psychosis in exposed individuals may be much more common, albeit at attenuated levels. Findings are based on a population sample of 2548 adolescents and young adults aged originally 14–24 years, and followed up over almost 5 years up to ages 17–28 years. Trained psychologists assessed all these subjects with the core psychosis sections on delusions and hallucinations of the Munich-Composite International Diagnostic Interview. Growing up in an urban area was associated with an increased risk of expression of psychosis in the adolescents and young adults (adjusted OR 1.31, 95% CI 1.03–1.66). The proxy environmental risk factor that urbanicity represents may shift a relatively large section of the adolescent population along a continuum of expression of psychosis. Other causal influences may be required to make the transition to schizophrenia in adult life.

Objectives: To investigate the relationship between ecstasy use and mental disorders in a representative sample of adolescents and young adults. Method: Data for this investigation were drawn from the Early Developmental Stages of Psychopathology (EDSP) study, an epidemiological-longitudinal study in which 14-24 year-olds were examined prospectively over a period of about 4 years. Results are based on N=2462 participants who completed the whole study period and for whom drug use behavior could be determined. Results: (1) Ecstasy users, compared with non-users, were at significantly increased risk of DSM-IV substance related disorders, including alcohol use disorders (52.6 vs. 15.6%; OR=5.6, 95% CI=3.8-8.1). Further, ecstasy users also had a higher risk of alcohol use disorders, when compared with users of other illicit substances (52.6 vs. 40.3%; OR=1.7, 95% CI=1.1-2.4). (2) Ecstasy users had significantly higher rates for almost all DSM-IV mental disorders examined when compared with non-users (any non-substance use disorder: 68.7 vs. 44.5%; OR=3.1, 95% CI=2.1-4.4) and compared with users of other illicit drugs (any non substance use disorder: 68.7 vs. 55.5%; OR=1.8, 95% CI=1.2-2.6). (3) Ecstasy users also reported significantly higher rates of prescription medicine use, though they did not use more medical services than non-drug users. (4) Analyses of temporal patterns of ecstasy use and disorder onset revealed that the first use of ecstasy was secondary to the onset of DSM-IV mental disorders in the majority of cases. Still, subjects with mental disorders at baseline also showed a significantly increased risk for initiation of ecstasy use during the 4-year follow-up period. Conclusions: Care should be taken in cross sectional studies in interpreting mental disorder signs and symptoms merely as a consequence of ecstasy use, as ecstasy use might be associated with the use of multiple substances, and onset of mental disorder is more likely to precede rather than to follow use of ecstasy and related substances.

This special issue was prepared within the framework of the European College of Neuropsychopharmacology (ECNP) Task Force on “Size and Burden of Mental Disorders in Europe”. The core aim of the Task Force was to describe the prevalence and the burden of treated and untreated mental disorders in all European member states and to highlight needs for further research. Ten state-of-theart epidemiological papers summarize the outcome of this project, making an attempt to provide for the first time ever prevalence estimates for a wide range of mental disorders, as well as for dementia and Parkinson’s disease in 28 European countries. These data also provide input for the European Brain Council (EBC, http://www.ebc-eurobrain. net) Initiative “Cost of Disorders of the Brain in Europe” aiming at estimating the cost of major classes of mental, neurological and neurosurgical disorders and conditions in Europe.

Background: Although positive effects of physical activity on mental health indicators have been reported, the relationship between physical activity and the development of specific mental disorders is unclear. Method: A cross-sectional (12-month) and prospective-longitudinal epidemiological study over 4 years in a community cohort of 2548 individuals, aged 14–24 years at outset of the study. Physical activity and mental disorders were assessed by the DSM-IV Composite International Diagnostic Interview (CIDI) with an embedded physical activity module. Multiple logistic regression analyses controlling for age, gender and educational status were used to determine the cross-sectional and prospective associations of mental disorders and physical activity. Results: Cross-sectionally, regular physical activity was associated with a decreased prevalence of any and co-morbid mental disorder, due to lower rates of substance use disorders, anxiety disorders and dysthymia. Prospectively, subjects with regular physical activity had a substantially lower overall incidence of any and co-morbid mental disorder, and also a lower incidence of anxiety, somatoform and dysthymic disorder. By contrast, the incidence of bipolar disorder was increased among those with regular physical activity at baseline. In terms of the population attributable fraction (PAF), the potential for preventive effects of physical activity was considerably higher for men than for women. Conclusions: Regular physical activity is associated with a substantially reduced risk for some, but not all, mental disorders and also seems to reduce the degree of co-morbidity. Further examination of the evidently complex mechanisms and pathways underlying these associations might reveal promising new research targets and procedures for targeted prevention.