Laska, K. M., Gurman, A. S., & Wampold, B. E. (2014). Expanding the lens of evidence-based practice in psychotherapy: A common factors perspective. Psychotherapy, 51(4), 467-481.
In this wide ranging review of the Common Factors (CF) perspective in psychotherapy, Laska and colleagues tackle the complex issues of defining CF and describing the evidence. The authors argue that CF in psychotherapy are not a vague set of ideas that fit under the label of “non-specific factors” or “relationship factors”. They also state that there is an unnecessary dichotomy between the concepts of empirically supported treatments (EST) and CF. In EST, specific and brief manualized therapies for specific disorders are tested in highly controlled randomized trials. ESTs purport that efficacious psychotherapies contain specific techniques based on an articulated theory of the disorder, and a specific mechanism of change for that disorder (e.g., depression is partly caused by depressogenic beliefs and so CBT for depression specifically targets cognitive distortions). There are published lists of ESTs for many disorders. However, Laska and colleagues argue that there is little evidence of the specificity of these treatments. For example, in dismantling studies an intervention like CBT for depression is compared to a dismantled version that removes an “active ingredient” [e.g., by providing only behavioral activation as an intervention], with little difference in patient outcomes between the full and dismantled versions. Further, for a number of disorders, several therapies based on very different theories of the disorder and of change are equally effective. In contrast to the EST approach, Laska and colleagues describe the CF approach which focuses on factors that are necessary and sufficient for patient change across psychotherapies, such as: (1) an emotional bond between client and therapist, (2) a healing setting for therapy, (3) a therapist who provides a theoretically and culturally relevant explanation for emotional distress, (4) an adaptive explanation that is acceptable to clients, and (5) procedures that lead clients to do something that is positive and helpful. Nevertheless, CF does not provide therapists with a license to do whatever they want without considering the evidence of a therapy’s efficacy. Rather CF does encourage therapists to make use of specific factors found in ESTs and to practice with a purpose. In support of the importance of CF, Laska and colleagues review the evidence from a number of meta analyses that show that CF (i.e., alliance, empathy, collaboration, positive regard, genuineness, therapist effects) each account for 5% to 11.5% of patient outcomes. These are moderate effects. Specific ingredients of psychotherapies or differences between ESTs account for 0% to 1% of patient outcomes, which represent small effects.
An excessive focus or reliance on empirically supported therapies (EST) may unnecessarily limit what the profession and funders consider to be evidence-based practice. A common factors (CF) approach provides scientific evidence for effective therapeutic practices that are necessary in addition to the specific treatments found in lists of ESTs. To be effective, therapists should be able to: (1) develop a therapeutic alliance and repair ruptures to the alliance, (2) provide a safe context for the therapy, (3) be able to communicate sound psychological theory for the client’s distress based on evidence, (4) suggest a course of action that is based on evidence, and (5) conduct therapy based on established theories of distress and healing. Laska and colleagues argue that systematic patient progress monitoring and ongoing monitoring of the therapeutic alliance may be an effective method of quality improvement of therapists’ outcomes. Progress monitoring may provide therapists with information about areas for continuing education to improve their patients’ outcomes.