What are Acceptable Risks to Human Subjects in a Treatment Study?
The purpose of this study was to test the hypothesis that two types of psychotherapy were as effective as antidepressant drug therapy in treating depression. Subjects were patients diagnosed as having major depressive disorder (characterized by difficulty thinking, recurrent thoughts of death or suicide attempts, loss of interest or pleasure in activities, appetite and sleep disturbances, and feelings of worthlessness or guilt), who had come for treatment to one of several psychiatric outpatient centers.
The purpose of this study was to investigate the effectiveness of two forms of brief psychotherapy for patients with major depressive disorder: interpersonal psychotherapy and cognitive behavior therapy. At the time this study was conducted there was scientific evidence that drug therapy with an antidepressant drug called imipramine hydrochloride was an effective treatment for this population.
The goal of this study was to determine whether psychotherapy treatments for depression would be as effective as the antidepressant drug therapy. A primary hypothesis tested in this study was: Patients given imipramine treatment, interpersonal psychotherapy, or cognitive behavior therapy would demonstrate significantly higher rates of recovery from major depression than patients treated with a placebo pill (a substance with no active ingredients).
The subjects were patients diagnosed as having major depressive disorder (characterized by loss of interest or pleasure in activities, appetite and sleep disturbances, decreased energy, feelings of worthlessness or guilt, difficulty thinking, and recurrent thoughts of death or suicide attempts) who had come for treatment to one of several psychiatric outpatient centers participating in the research project.
All treatments were planned to be 16 weeks in length. The interpersonal therapists sought to help the patients better understand their interpersonal problems and improve ways of relating to others. The cognitive behavior therapists used techniques to correct the patients' negative and distorted views about themselves and the world. In addition to the weekly administration of the medication or placebo pill, the drug therapy and pill-placebo conditions included a controlled management component.
Of the 239 patients included in the study, 59 either dropped out or were withdrawn by the experimenters before the study was completed because of negative treatment-related reasons (e.g., dissatisfaction with the condition they had been assigned to or intolerable side effects). Treatment differences in the reduction of depressive symptoms only emerged for patients who had been originally diagnosed as most severely depressed with those in the imipramine doing best, placebo doing worst, and the two psychotherapies in between, with the interpersonal therapy generally closer to imipramine.
The data from the Elkin et al study suggest that for severely depressed patients imipramine treatment and, to a lesser extent, interpersonal therapy can reduce depressive symptoms. The results indicated no evidence that interpersonal therapy or cognitive behavior therapy is more effective than the placebo pill condition in treating less severely depressed patients.
"National Institute of Mental Health Treatment of Depression Collaborative Research Program," Irene Elkin, M. Tracie Shea, John T. Watkins, Stanley D. Imber, Stuart Sotsky, Joseph F. Collins, David R. Glass, Paul Pilkonis, William R. Leber, John P. Docherty, Susan J. Fiester, Morris B. Parloff (1989), Archives of General Psychiatry, 46, 971-983