A regulatory Apologia -: A review of placebo-controlled studies in regulatory submissions of new-generation antidepressants

Data on percentage of patients experiencing a relevant response (>50% reduction of the baseline Hamilton Depression Scale (HAMD) score), average baseline severity and sample size were retrieved for all placebo-controlled studies in regulatory submissions of SSRIs and SNRIs between 1984 and 2003. Overall there was 16%-units (95% CI: 12; 20) more responders on active drug compared to placebo. There was no evidence of a diminishing magnitude of effect with tower severity at baseline. With one exception significant differences varying between 13.5 and 19.3%-units were demonstrated for the individual antidepressants. Statistically significant mean differences versus placebo in change in HAMD are not a proper basis for evaluation of clinical relevance and are not sufficient for approval. Differences in the percentage of patients experiencing a clinically relevant response should also be demonstrated. In this respect, the approved SSRIs and SNRIs were found superior to placebo, independent of severity of depression. (C) 2008 Elsevier B.V. and ECNP. All rights reserved.