JUST-PUBLISHED AMERICAN PSYCHOLOGIST STUDY ON THERAPY WITH ADOLESCENTS MISLEADINGLY CLAIMS THAT CBT IS THE MOST EFFECTIVE TREATMENT MODALITY
A recent meta-analysis (Weisz, et al., 2017) in the APA’s publication, American Psychologist, exemplifies the kind of bias that has been shown by the American psychology community in favor of CBT and against psychodynamic treatments.
This meta-analysis broke the groups into behavioral (including CBT) and non-behavioral treatments of adolescents. They report that the CBTs’ effectiveness had a stronger effect size than the “non-behavioral” treatments. They wrote: “only youth-focused behavioral therapies (including cognitive-behavioral therapy) showed similar and robust effects across youth, parent, and teacher reports.”
At first glance this study seems to be important, as meta-analyses were used to generate large sample sizes. But on closer inspection, the sample size of studies assessing so-called “non-behavioral” treatments was 8 and the “non behavioral” treatments were undefined. In contrast, the CBT group included 73 studies This undermines any scholarly claim to be made by these authors in a widely read psychology journal, and is fundamentally misleading.
This is because:
1) it compares a relatively homogenous group of studies with a group of studies that may be quite heterogenous and have different levels of proven effectiveness and validity, and
2) the significant discrepancy in size of the two groups of studies was not adequately taken into account in drawing conclusions from their respective effect sizes. Thus, statistically, the ‘non-behavioral’ group’s having a smaller (but significant) effect size compared to the behavioral group would be expected, regardless of the actual impact of each group of interventions. The case made by the study’s authors that CBT is superior to other forms of treatment is, in fact, not a statistically sound conclusion.
This is the kind of study that is hurtful to patients as it supports the incorrect conviction held by many government agencies, insurance companies and the physicians who often make referrals for treatment that CBTs are the most effective form of treatment.