Establishing non-inferiority in treatment trials in psychiatry: guidelines from an Expert Consensus Meeting.

Comparing the efficacy of different treatments in psychiatry is difficult for many reasons, even when they are investigated in "head-to-head" studies. A consensus meeting was, therefore, held to produce best practice guidelines for such studies. This article presents the conclusions of this consensus and illustrates it using published data in the field of antidepressant treatment of generalized anxiety disorder.