Comparison of specific and nonspecific factors in a group cognitive therapy for depression.

Research into the efficacy of psychotherapy has often reported equivalence in treatment outcome when comparing different therapies. These findings have been interpreted as evidence for what are variously termed placebo, common or nonspecific processes. We suggested that this issue is best examined in comparison of specific and nonspecific processes in the action of a specified therapy and disorder. No comparisons of this nature have yet been reported in relation to cognitive therapy for depression. This study compared specific processes (automatic thoughts and dysfunctional attitudes) and major common processes (satisfaction with therapy and client evaluation of therapist) in the action of a group cognitive therapy for depression. Sixty patients suffering from major depression received a 12 week course of group cognitive therapy. Results from hierarchical regression suggested that the specific processes of cognitive therapy were more associated with reduction in depression than common processes which contributed to the prediction of reduction in depression via specific processes.