A major dilemma in psychotherapy outcome research: Disentangling therapists from therapies

In interpreting results of psychotherapy outcome studies, particularly thos e of comparative studies, it is often difficult to disentangle the effects due to the treatments per se from those that may be due to differential com petence and other characteristics of the therapists carrying out the treatm ents. This article attempts to address this general dilemma in psychotherap y outcome research, drawing on the experience and findings of the NIMH Trea tment of Depression Collaborative Research Program. Issues discussed includ e the nature of the overall therapist sample, variability in therapist effi cacy, therapist characteristics, training and supervision of therapists, an d adherence and competence in carrying out a treatment. Implications discus sed include the need to provide, both in presentations of the results of in dividual outcome studies and in dissemination of information regarding "emp irically validated treatments," critical information about the therapists c arrying out the treatment.