Objective: The purpose of this article is to present the current status and future needs of old age psychiatry in relation to evidence-based health care. Method: The opportunities and difficulties of evidence-based medicine as applied to old age psychiatry are described. Depression is used as a specific example. The role of the Cochrane Collaboration and of clinical guidelines in dealing with these difficulties are discussed. Results: There has been a tendency for drug studies to focus on younger age groups and to exclude patients with comorbidity or polypharmacy. Aspects of clinical management separate from drugs are given insufficient attention. The generalizability of current studies is a problem in old age psychiatry. Conclusions: Psychiatry is no less part of medicine than any other specialty. Increased attention to studies of effectiveness, as opposed to efficacy, is indicated. The Cochrane Collaboration is an international network which promotes and conducts systematic reviews of the effectiveness of health care. Systematic reviews can increase the generalizability of the current knowledge base and better define the needs for future research.