Patients’ treatment expectancies in clinical trials of antidepressants versus psychotherapy for depression: a study using hypothetical vignettes

Previous research on patients’ expectancies for improvement in clinical trials typically has been conducted after patients have already agreed to participate in a study. Depressed patients (n = 55) read 3 vignettes describing hypothetical clinical trials of antidepressant vs pill placebo, antidepressant vs antidepressant, and psychotherapy vs psychotherapy. Patients reported greater overall acceptability for psychotherapy over antidepressants. Patients had significantly greater expectancies for symptom reduction in either active comparator (medication or psychotherapy) compared with the placebo-controlled design. They also reported greater anticipated improvement and willingness to participate in the psychotherapy trial compared with either medication trial design. Patients’ differential expectancies based on study design could lead to different patient populations being selected for these studies and influence clinical improvement.