THE AMERICAN JOURNAL OF PSYCHIATRY Conceptual and Methodological Issues in Comparative Studies of Psychotherapy and Pharmacotherapy, I: Active Ingredients and Mechanisms of Change

There has recently been an increased focus on corn-paring the effectiveness of drugs and psychotherapy in the treatment of rnental disorders. The rnarked differ-ences between these two treatment forms raise many conceptual and methodological problems for the inves-tigator. In a two-part series, the authors discuss a num-ber of these conceptual issues and their implications f or research design, implementation, and interpreta-tion of findings. Part I focuses on differences in the active ingredients and hypothesized mechanisms of change ofpsychotherapy and pharmacotherapy. Issues addressed include the need for standardization of treatments, adequate delivery of treatments, and con-trolling for factors other than the active ingredients of each treatment. (Am J Psychiatry 1988; 145:9O9-97) T he two major forms of treatment for mental dis-orders are pharmacotherapy and psychotherapy. Over the last three decades hundreds of studies have examined the effectiveness of each of these forms of treatment. These have included studies comparing var-ious drugs with each other and with placebo condi-tions and studies comparing various forms of psycho-therapy with each other and with “no treatment,” “waiting list, ” “attention-placebo, ” or other control conditions. A considerably smaller number of studie