A Randomized Survey of the Public's Expectancies and Willingness to Participate in Clinical Trials of Antidepressants Versus Psychotherapy for Depression.

Background: Expectancies and treatment preferences are known to affect the outcomes of patients enrolled in clinical trials for depression, but there is little research on their influence when the public is considering participation in these trials.

Method: We conducted an online survey (May 2013) in which participants (N = 615) were randomly assigned to read hypothetical descriptions of clinical trials for depression based on 1 of the following study designs: medication versus placebo, medication versus medication, psychotherapy versus placebo, or psychotherapy versus psychotherapy. Afterward, individuals rated willingness to participate in the trial, logic and credibility of the treatments, and expected success and improvement in symptoms.