The Epidemiological need-model frequently advocated in literature on planning of (mental) health care is analysed in the frame-work of modern sociological theories. The author's basic concept is that the system's quality and size should be based on the incidence and frequency of subjective stress-provoking need situations in society. Four fields of research are distinguished:

• Factors determining the incidence and frequency of need situations (including recurrence);
• factors causing the selfliquidation of cases;
• factors impeding the client to come info contact with the psychiatrist or with other professionals working in the field of mental health care;
• factors preventing treatment or its effectiveness.

It appears that the applicability of the epidemiological need-model is severely restricted by the lack of adequate information. This will have to be gathered by means of mental health surveys and by an analysis of the client records of the psychiatrist and others working in mental health care and connected fields.