Methodology of measuring the efficacy of antidepressants--European viewpoint.

The 1988 Consensus Conference on the Methodology of Clinical Trials of Antidepressants developed a European viewpoint on the methodology of measuring the efficacy of antidepressants. Placebo-controlled, parallel group trials are necessary but problematic. To test the efficacy of a new antidepressant, only patients with recognized depressive disorder of at least moderate severity should be included. In double-blind trials comparing a novel antidepressant with a well known reference drug, effective doses of the reference drug should be used. Efficacy can best be demonstrated in non-treatment-resistant patients. The recommended length of trials for proof of antidepressant efficacy is at least 4 weeks.