Examining the Evidence on Augmentation with Atypical Antipsychotics

There is mounting evidence to suggest that the efficacy of all available antidepressants when used as monotherapy to treat major depressive disorder (MDD) is, at best, modest. For example, a meta-analysis of all double-blind placebo-controlled studies of antidepressants published since 1980 revealed response rates of 53% for antidepressants versus 36% for placebo (difference in response rate of 16.8%) (Slide 1). To make matters worse, if one is to assume that “negative trials” (ie, trials which do not demonstrate the superiority of a drug over placebo) are less likely to be published than “positive trials” (trials which demonstrate the superiority of a drug versus placebo), it is quite possible that the margin of efficacy of antidepressants when compared to placebo is ≤16.8%. Thus, if one were to include all unpublished along with published double-blind, placebo-controlled trials of antidepressants for MDD, this efficacy margin could be ≤10%.