Objective – To consider some of the problems that may arise when the results of clinical trials are applied uncritically to everyday clinical practice. To show how an epidemiological perspective makes it easier to identify these problems. Method – A review of clinical trials to illustrate problems of: (a) covert selection bias in individual trials, (b) bias in the selection of trials included in reviews and meta-analyses. Results – Several kinds of selection bias are known to exist. In particular, trials with negative results are less likely to be published in widely read journals than are trials of similar scientific quality reporting positive results. Conclusions – There are dangers in applying the results of trials to clinical practice in an uncritical way. These dangers can be avoided by adopting and epidemiological perspective, seeking for clinical trials that are representative of the whole population of trials. The Cochrane Collaboration has been established to minimize biases in reviews and meta-analysis. The first Cochrane Centre on Schizophrenia has been established in Oxford and others are planned.

Objective – The paper discusses conceptual, methodological and clinical issues of comorbidity from the perspective of more recent epidemiological studies. Further the potential causal and pathogenic role of temporally primary disorders for the onset of secondary disorders is evaluated. Results – The available data suggest so far that comorbidity (a) is not an artefact of assessment strategies, sampling or design features, (b) is specific in different disorders, (c) is particularly frequent in anxiety and affective disorders, (d) affects systematically the course of the comorbid conditions and (0 might be related to symptom progression models. Conclusions – Furthermore, evidence is presented that specific forms of primary anxiety disorders affect the risk for secondary depressive disorders, increase the likelihood of non-remission as well as the number of subsequent depressive episodes.

Objective – The analysis aims to identify the main patterns of Psychiatric Services provided by Local Health Unities in Lombardy. Setting – Data were collected by regional psychiatric information system in Lombardy in 1992 and 1993, concerning resources and activity. Design – We developed Cluster Analysis based on previously selected indicators of facilities, staff and activity. Multivariate analisys was performed in order to eliminate redundancy of information. Results – Five clusters corresponding to different patterns of psychiatric services were identified. In the first cluster services are particularly concerned with admissions (in private hospital, as well); other community activities can be considered quite dull both in composition of teams and variety of therapy. In the unities of the second cluster we pointed out low rates of community activities (mainly inside and hardly diversified) and admissions as well. The third cluster is distingueshed by an intensive community activity (both in quantity and variety) and turning to private sector for admissions, maybe because of a lack of rehabilitative facilities. Unities belonging to the fourth cluster have got many structures and a lot of staff dedicated to the hospital activity and to a intense (but little diversified) community activity. In the fifth cluster psychiatric services have got many rehabilitative facilities and community staff are well diversified; the considerable (but little diversified) community activity is carried outside. Conclusions – The community psychiatric services in Lombardy are not homogeneous and it is possible to identify five different and well definied patterns. The cluster analisys is useful to follow up the model, using information system data.

Objective To compare the prevalence of psychological discomfort in four groups of young people of different social status (metalworkers exposed and not exposed to mental health occupational risks, individuals unemployed or seeking their first job and full-time students). The study also evaluates among the same groups, six years after, the changes in status and in the rates of psychological discomfort. Design – The subjects, selected through an appropriate random procedure, are males, aged between twenty and twenty-nine, resident in the same geographical area for at least 10 years and still living with their families. 157 young men were involved, divided into the following four groups: metalworkers exposed to mental health occupational risks (n° = 30); metalworkers «not exposed» (n° = 57); unemployed (n° = 40); full-time students (n° = 30).

The prevalence of psychological discomfort has been compared in the four groups; six years after, within 116 subjects participating in the follow-up study, the changes in status and in psychological discomfort have been examinated. Setting – The survey was conducted in Cento (Ferrara, Northern Italy), an area with a healthy local economy and a comparatively low unemployment rate. In 1987 and in 1993 all young men were interviewed at home, after telephone contact, by the same psychologist. Main outcome measures - In the 1987 survey, to each subject were administered a «Social Position and Health Schedule» (SPH) and a previously validated questionnaire, to determine the index of psychological discomfort (IDP).

Through the «Occupational Risk Questionnaire» (ORQ) the metalworkers were also divided into two groups (exposed and not exposed to mental health occupational risks).

In 1993 the participants in the follow-up completed the same «IDP-Questionnaire» and a «Social and Occupational Position Schedule» (SOP) to give detailed informations on both labour turn-over and/or shifts in social status over the six years period. Results – In the 1987 survey significantly higher frequencies and averages were found in the group of metalworkers exposed to mental health risks, while no statistically significant results were noted in the other groups, including the group of unemployed. The main finding of the follow-up study relates to those metalworkers who, in the follow-up period, have changed their manual job to another type of employment and whose score visa-vis psychological discomfort was better than the rest of the group. Our findings indicate also that those young men seeking their first job who had found employment during the follow-up period, experienced an increase in psychological discomfort. Conclusion The most interesting aspect of our survey seems to concern the relationships between occupational prospects and mental health among young men living in an area characterized by a healthy local economy. Further studies on the students and the unemployed (and their possible occupational outcomes) are however needed.