The Great Psychotherapy Debate: Since in April, 2015 I review parts of The Great Psychotherapy Debate (Wampold & Imel, 2015) in the PPRNet Blog. This is the second edition of a landmark, and sometimes controversial, book that surveys the evidence for what makes psychotherapy work. You can view parts of the book in Google Books.
The conduct of psychotherapy trials almost always requires that therapists be adherent and competent in delivering a manualized therapy intervention. Treatment adherence usually refers to the extent to which a therapist used the intervention prescribed by a treatment manual. Therapist competence refers specifically to a therapist’s skill in delivering the therapy. So “competence” in the context of psychotherapy research typically refers only to performing a certain type of treatment. Wampold and Imel argue that these definitions are consistent with a Medical Model of psychotherapy that emphasizes delivering specific active ingredients of a treatment. The Contextual Model of psychotherapy, on the other hand might define a therapist as competent to the extent that the therapist is interpersonally skilled, empathic, and able to engage clients in the actions of the therapy. Wampold and Imel report on a meta analysis of 28 studies conducted by Webb and colleagues (2010) who found a small and non-significant relationship between therapist adherence and patient outcomes (r = .02), and a small and non-significant relationship between therapist competence and patient outcomes (r = .07). Type of treatment (e.g., CBT, IPT, dynamic) did not affect these associations – in other words adherence and competence were not more important to CBT than to other treatments. However, competence seemed to be more important for the treatment of depression (r = .28). Perhaps depression responds better to specific techniques. The finding that competence was generally not related to outcomes was surprising, however generally competence is narrowly defined as how well a therapist delivered the treatment not how well the therapist was able to establish a therapeutic context. Previous researchers concluded that when clients liked working with a therapist, clients got better, and therapists were rated as more competent as a result. A number of studies appear to indicate that therapist competence is really a function of the client’s characteristics not to what the therapist does. For example, clients with more severe personality problems could make a therapist appear less competent, and these clients may have poorer outcomes. If this is the case, it would create a paradoxical situation in which therapists’ appearance of competence (i.e., ability to deliver a manualized intervention well) is largely determined by the client and not by the therapist.
In contrast to the findings about adherence and competence, the therapeutic alliance is robustly related to patient outcomes. Also in contrast, the size of the alliance-outcome relationship is almost entirely due to the skills of the therapist, not the client’s characteristics. In other words, therapist competence is not a matter of whether they can do a good job of following a manual, but rather therapist competence is likely a matter of creating the right conditions (i.e., interpersonal skill, alliance, empathy, etc.) for delivering evidence-based interventions by which many clients improve. However, some therapists are better at these facilitative interpersonal skills than others.