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Handbook of Psychotherapy and Behavior Change: Starting in March 2013 I will review one chapter a month from thenHandbook of Psychotherapy and Behavior Change in addition to reviewing psychotherapy research articles. Book chapters have more restrictive copy right rules than journal articles, so I will not provide author email addresses for these chapters. If you are interested, the Handbook table of content can be viewed on Amazon.

Burlingame, G.M., Strauss, B., & Joyce, A.S. (2013). Change mechanisms and effectiveness of small group treatments. In M.J. Lambert (Ed.) Bergin and Garfield’s handbook of psychotherapy and behaviour change (6^thed.), pp. 640-689. Hoboken, N.J.: Wiley.

Group treatments are the most common types of interventions offered in community, organizational, institutional, and hospital settings. They occur in many contexts including: outpatients, inpatients, day hospital, private practice, community health, support groups, drop-in centres, and educational organizations. Despite the extent of their application, group treatments receive relatively little research attention compared to individual psychotherapy or medication interventions. (Not to mention the pervasive and mistaken notion that group therapy is like doing individual therapy with 8-10 patients at once, or that individual therapy training is sufficient to be expert in group therapy). There are many reasons for this relatively lower amount of research, including the lack of expertise in and understanding of group practice among clinical researchers, and the substantially greater difficulty in running a clinical trial of group therapy (of the latter I have ample experience and war wounds). Nevertheless, Burlingame and colleagues summarized more than 250 studies that estimated the efficacy or effectiveness of group therapy for 12 disorders or populations. The findings indicate good or excellent evidence for the efficacy of group treatments for many disorders or patient groups (e.g., panic, social phobia, OCD, eating disorders, substance abuse, trauma related disorders, coping with breast cancer, schizophrenia, and personality disorders). There are also promising results for other disorders (e.g., mood, pain, and inpatients). Although there are substantially more studies on group CBT, most studies that compare different models (including IPT, psychodynamic, DBT, etc.) often produce equivalent outcomes. There is also lots of evidence that group therapy is as effective as individual therapy or medications for most disorders. In one U.S. study on panic disorder, group psychotherapy was the most cost effective (i.e., cost per rate of improvement) of the interventions ($246) compared to individual therapy ($565) and medications ($447). There is also research on the effects of specific characteristics of groups. For example, research on group composition (i.e., heterogenous vs homogeneous in terms of patient population or functioning) has produced mixed results, though there is emerging evidence that heterogeneous groups tend to benefit those who are lower functioning. Further, research on group cohesion (i.e., the bond between the individual and the group) which is a construct related to but distinct from alliance, is positively associated with treatment outcomes with a moderate effect size.

Practice Implications

Group treatments are as effective as individual therapy or medications, and are likely more cost effective. However group therapy is more complicated to practice and to study. Burlingame and colleagues suggest using empirically validated interventions, and ongoing assessment of client outcomes. They also suggest following the American Group Psychotherapy Association (AGPA) practice guidelines (see the Resources page on our web site), that include best practices for creating a successful group, appropriately selecting clients, preparing clients for group, evidence based interventions, and ethics issues related to group practice. Finally, Burlingame and colleagues emphasize using AGPA recommended measures and resources in developing and assessing a therapy group. These include: (1) group selection and group preparation which may involve handouts for group leaders and members about what to expect and how to get the most from group therapy; (2) assessing group processes repeatedly during group therapy using measures like the Therapeutic Factors Inventory or the Working Alliance Inventory; and (3) measuring client outcomes by using an instrument like the Outcome Questionnaire-45. Repeated measurement and feedback of processes and outcomes to the therapist may improve the group’s effectiveness.

Niemeyer, H., Musch, J., & Pietrowsky, R. (2013). Publication bias in meta-analyses of the efficacy of psychotherapeutic interventions for depression. Journal of Consulting and Clinical Psychology, 81, 58-74.

Meta-analyses are important ways of summarizing effects of medical and psychological interventions by aggregating effect sizes across a large number of studies. (Don’t stop reading, I promise this won’t get too statistical). The aggregated effect size from a meta analysis is more reliable than the findings of any individual study. That is why practice guidelines almost exclusively rely on meta analyses when making practice recommendations (see for example the Resources tab on this web site). However meta analyses are only as good as the data (i.e., studies) that go into them (hence, the old adage: “garbage in, garbage out”). For example, if the studies included in a meta analysis are a biased representation of all studies, then the meta analysis results will be unreliable leading to misleading practice guidelines. One problem that leads to unreliable meta analyses is called publication bias. Publication bias often refers to the tendency of peer reviewed journals not to publish studies with non-significant results (e.g., a study showing a treatment is no better than a control condition). Publication bias may also refer to active suppression of data by researchers or industry. Suppression of research results may occur because an intervention’s effects were not supported by the data, or the intervention was harmful to some study participants. In medical research, publication bias can have dire public health consequences (see this TED Talk). There is lots of evidence that publication bias has lead to a significant over-estimation of the effects of antidepressant medications (see Turner et al (2008) New England Journal of Medicine). Does publication bias exist in psychotherapy research, and if so does this mean that psychotherapy is not as effective as we think? A recent study by Niemeyer and colleagues (2013) addressed this question with the most up to date research and statistical techniques. They collected 31 data sets each of which included 6 or more studies of psychotherapeutic interventions (including published and unpublished studies) for depression. The majority of interventions tested were cognitive behavioral therapy, but interpersonal psychotherapy, and brief psychodynamic therapy were also included. The authors applied sophisticated statistical techniques to assess if publication bias existed. (Briefly, there are ways of assessing if the distribution of effect sizes across data sets fall in a predictable pattern called a “funnel plot” – specific significant deviations from this pattern indicate positive or negative publication bias). Niemeyer and colleagues found minimal evidence of publication bias in published research of psychotherapy for depression. This minimal bias had almost no impact on the size of the effect of psychotherapy for depression.

Practice Implications

This is a very important result indicating that despite a minor tendency toward a selective publication of positive results, the efficacy of all reviewed psychotherapy interventions for depression remained substantial, even after correcting for the publication bias. Niemeyer and colleagues’ findings demonstrate that publication bias alone cannot explain the considerable efficacy of psychotherapy for depression. Psychotherapeutic interventions can still be considered efficacious and recommended for the treatment of depression.

Author email address: helen.niemeyer@hhu.de

Handbook of Psychotherapy and Behavior Change: The Handbook of Psychotherapy and Behavior Change is perhaps the most important compendium of psychotherapy research covering a large number of research areas. The Handbook is updated approximately every 10 years, and the most recent 6^th edition was published in January 2013. In the coming months I will review one chapter a month in addition to commenting on psychotherapy research articles. Book chapters have more restrictive copy right rules about distributing content, so I will not provide author email addresses for these chapters. If you are interested, you can view the table of contents on Amazon.

Lambert, M.J. (2013). The efficacy and effectiveness of psychotherapy. In M.J. Lambert (Ed.) Bergin and Garfield’s handbook of psychotherapy and behaviour change (6^th ed.), pp169-218. Hoboken, N.J.: Wiley.

This comprehensive chapter in the Handbook reviews research on the efficacy and effectiveness of psychotherapy. Lambert’s reviews focus on meta-analyses, which is a way of summarizing effect sizes in a research area. The bottom line is that psychotherapy is effective so that 40% to 60% of clients show substantial benefit in controlled research trials, though the effect is likely smaller in routine practice.  Concurrently, a consistent proportion of adults (5% to 10%) deteriorate during psychotherapy. Patients who receive formal treatment are better off than those who receive no treatment, and bona fide treatments are superior to control conditions that provide only some aspects of effective treatment. When psychotherapy is offered by skilful therapists, on average clients experience appreciable gains and return to normal functioning. Fifty percent of patients achieve clinically significant gains after 8 sessions, and 50% achieve recovery after about 20 sessions of psychotherapy. The effects of psychotherapy tend to be long lasting. For example, only 25% treated depressed patients relapse, whereas 50% of those who receive antidepressants relapse. Research continues to support those therapies that have been rigorously tested, and differences in effectiveness between therapy types (e.g., cognitive behavioural therapy (CBT), psychodynamic, interpersonal, etc.) tend to be small or negligible for many disorders. Cognitive behavioural therapy is still the most tested therapy modality, though other treatments are also accumulating evidence of efficacy. Treatment is likely facilitated by a therapeutic relationship that is characterized by trust, understanding, acceptance, kindness, and warmth. The effect of the therapist providing the therapy is at least as large as the effect of different therapy techniques. That is, some therapists are unusually effective, whereas others may not help the majority of patients who seek their services. Continuous monitoring of outcomes and providing regular feedback to the therapist improves the therapy’s effectiveness.

Practice Implications

Providers and patients can be assured that a broad range of formally defined and tested psychotherapies when provided by skilful therapists are likely to result in appreciable gains in clients including a return to normal functioning. Therapy relationships characterized by trust, understanding, acceptance, and warmth can greatly facilitate change in depression, anxiety, inadequacy, and inner conflicts. When making a decision about which therapy to choose, clients would be wise to consider the therapist as a person at least as much as the type of therapy being offered. Treatment efforts should be based on the best evidence available for treatment types, therapist behaviors, and relationship factors. Routinely monitoring the effects of therapy with each patient will give the therapist ongoing information about their effectiveness and may improve their patients’ outcomes.