Background — In order to minimise retrospective recall in developing estimates of the prevalence of mental dis-orders in the general population, we conducted a prospective study of a cohort of youth from Zurich, Switzerland. Method — A 20 year prospective study of a community-based cohort aged 19-20 from Zurich Switzerland. The sample was enriched by subjects scoring high on the Symptom Checklist 90 R (Derogatis, 1977). A semi-structured diagnostic interview was administered by clinically experienced psychologists and psychiatrists. The six interviews from 1979 to 1999 assessed diagnoses and sub-threshold manifestations of major diagnostic categories (with the exception of schizophrenia) for the past twelve months, depending on the current DSM versions (DSM-IH, DSM-HI R, DSM-IV). Additional information on symptoms and treatment were collected for the years between the interviews. The reported prevalence rates are weighted for stratified sampling and cumulate the one-year rates of the six interviews. Results — The cumulative weighted prevalence rates for any psychiatric disorder were 48.6% excluding, and 57.7% including tobacco dependence. In addition 29.2% and 21.8%, respectively manifested sub-diagnostic syndromes. Overall there were no significant gender differences. The corresponding treatment prevalence rates were 22.4% and 31.1%, respectively for the diagnostic subjects and 6.9% and 6.1 %, respectively for the sub-diagnostic groups. The total treatment prevalence rate was 37.2% of the population (males 30.0%, females 44.1%). Conclusions — Our findings reveal that psychiatric disorders are quite common in the general population. When the spectra of mental disorders are considered, nearly three quarters of the general population will have manifested at least one of the mental disorders across their lifetime. Limitations — The data are based on a relatively small sample; a single age cohort, and the study was conducted in Zurich, Switzerland. These study features may diminish the generalisability of the findings.

Declaration of Interest: this work was supported by Grant 3200-050881.97/1 of the Swiss National Science Foundation, and Research Scientist Development Awards (MH 46376 and DA00293) from the US National Institutes of Health (Dr. Merikangas).

The two-dimensional bipolar spectrum described here comprises a continuum of severity from normal to psychotic and a continuum from depression, via three bipolar subgroups to mania. This combination of dimensional and categorical principles for classifying mood disorders may help alleviate the problems of underdiagnosis and undertreatment of bipolar disorders.

Background.Many patients with psychological or physical problems are interested in non-medical approaches. The reasons for the growing popularity of complementary and alternative medicine (CAM) are not well understood considering that evidence of the effectiveness of conventional therapies is greater than ever before. We have examined data from the Zurich Study to determine trends and predictors of CAM use in Switzerland.

Method.The Zurich Study is a longitudinal community study that was started in 1979 with a sample of 591 participants born in 1958 and 1959. In 1999, the last of six interview waves with face-to-face interviews was conducted. CAM use was analyzed with data from interviews in 1993 and 1999. Polytomous logistic regression analysis focused on the personal, demographic and sociocultural background of CAM users.

Results.CAM use in the last 12 months was reported by 21·9% of the participants in 1993 and by 29·5% in 1999. CAM use among those exhibiting either physical or psychological problems was in the ratio of two to one. There was a trend from alternative variants of CAM (homeopathy) to complementary ones (massage, osteopathy, acupuncture). The vast majority of CAM use was in addition to conventional therapies. Predictors of CAM use were, among others, attribution of physical complaints to stress and other psychological variables, very low education level in parents, and lacking political interest.

Conclusions.Besides the sociocultural background, characteristics such as the psychological attribution style play an important role in CAM use. CAM use in Switzerland is mainly of a complementary rather than an alternative nature.

Background. Clinical judgments about the likelihood of suicide attempt would be aided by an index of risk factors that could be quickly assessed in diverse settings. We sought to develop such a risk index for 12-month suicide attempts among suicide ideators.

Method. The National Comorbidity Survey Replication (NCS-R), a household survey of adults aged 18+, assessed the 12-month occurrence of suicide ideation, plans and attempts in a subsample of 5692 respondents. Retrospectively assessed correlates include history of prior suicidality, sociodemographics, parental psychopathology and 12-month DSM-IV disorders.

Results. Twelve-month prevalence estimates of suicide ideation, plans and attempts are 2·6, 0·7 and 0·4% respectively. Although ideators with a plan are more likely to make an attempt (31·9%) than those without a plan (9·6%), 43% of attempts were described as unplanned. History of prior attempts is the strongest correlate of 12-month attempts. Other significant correlates include shorter duration of ideation, presence of a suicide plan, and several sociodemographic and parental psychopathology variables. Twelve-month disorders are not powerful correlates. A four-category summary index of correlates is strongly related to attempts among ideators [area under the receiver operator characteristic curve (AUC)=0·88]. The distribution (conditional probability of attempt) of the risk index is: 19·0% very low (0·0%), 51·1% low (3·5%), 16·2% intermediate (21·3%), and 13·7% high (78·1%). Two-thirds (67·1%) of attempts were made by ideators in the high-risk category.

Conclusions. A short, preliminary risk index based on retrospectively reported responses to fully structured questions is strongly correlated with 12-month suicide attempts among ideators, with a high concentration of attempts among high-risk ideators.

Background. This study questions the 6-month duration criterion for generalized anxiety disorder (GAD) used in DSM-III-R and DSM-IV.

Method. In adults from age 20/21 to 40/41 in the prospective Zurich Cohort Study, four groups of generalized anxiety syndromes defined by varying duration (2 weeks, 1 month, 3 months and 6 months) were compared.

Results. Applying DSM-III (1979–1999) and DSM-III-R (1986–1999) criteria, there were no significant differences between the four groups in terms of family history of anxiety, work impairment, distress, treatment rates or co-morbidity with major depressive episodes (MDEs), bipolar disorder or suicide attempts. Only social impairment related to the length of episodes. The 6-month criterion of DSM-III-R and DSM-IV GAD would preclude this diagnosis in about half of the subjects treated for generalized anxiety syndromes.

Conclusions. In this epidemiological sample, the 6-month duration criterion for GAD could not be confirmed as clinically meaningful. GAD syndromes of varying duration form a continuum with comparable clinical relevance.

From the Zurich cohort study (n=591), the association of major depressive episodes and recurrent brief depression (RBD) with other psychiatric disorders is presented cross-sectionally at age 28 and 30 years, and over ten years (age 20 to 30 years). Longitudinally, the odds ratios of major depression are highest with dysthymia (4.4), generalised anxiety disorder (4.4), panic disorder (2.7), hypomania and agoraphobia (2.6), and social phobia (2.4). There is a significant association with cannabis consumption and smoking. Follow-up data over nine years are available for 41 patients with a major depressive disorder (MDD) and 62 with RBD: approximately 20% of MDD patients did not receive a diagnosis during follow-up. Major depression reoccurred in 32%, became bipolar in 24%, or developed into RBD in 24%. RBD remitted in 41 %, reoccurred in 35%, turned into major depression in 22%, and became bipolar in only 7%. Longitudinally, MDD and RBD show a symmetrical diagnostic change in a quarter of the cases. There is no substantial development of MDD or RBD into minor depression or generalised anxiety disorder. Thirteen per cent of those with RBD later developed panic disorder.

This paper describes the application of prospective longitudinal data from an epidemiological sample of young adults to define subtypes of major depression. Depression was classified on a spectrum from subthreshold manifestation of symptoms and duration at one end, to cases with recurrent episodes of depression meeting duration criteria for major depressive episodes at the other. There was a direct relationship between the severity of depression over the longitudinal course and both duration and recurrence of depressive episodes. The subgroup of depression with recurrence of both brief and longer duration episodes could be discriminated on most of the indicators of validity including symptoms, impairment, family history, and suicide attempts. In light of the young age of this cohort, the strong history of suicide attempts and other complications of depression among the subjects with recurrent depression was striking. These findings underscore the importance of employing course as a classification criterion of depression, and the inclusion of subthreshold episodes of depression in the characterisation of course.

In the longitudinal cohort study of young adults from the Canton of Zurich in Switzerland, two groups of eating problems were defined: binge eating and weight concerns. Subjects with these conditions were interviewed at the ages of 27–28 and 29–30 years. The binge eaters, mostly women, differed both from subjects with weight concerns and from controls. They had more severe eating problems and more anxiety and depression. Follow-up as well as retrospective data suggest that eating problems are persistent for the binge eaters, and, to a lesser extent, also for subjects with weight concerns. Even so, professional treatment is rarely sought by subjects with eating problems. These findings encourage long-term studies on eating problems in community samples.