Efficacy of third wave cognitive behavioral therapies in the treatment of posttraumatic stress: A meta-analytic study.

The purpose of the present study was to examine, via meta-analysis, the efficacy of third wave therapies in reducing posttraumatic stress (PTS) symptoms. A secondary aim was to identify whether treatment efficacy was moderated by treatment type, treatment duration, use of exposure, use of intent-to-treat samples, and treatment format (i.e., individual, group, both). Risk of bias was also assessed. A literature search returned 37 studies with a pooled sample of 1268 participants that met study inclusion criteria. The mean differences between pre- and post-treatment PTS symptoms were estimated using a random effects model (i.e., uncontrolled effect). Additionally, in a subset of studies that utilized a control condition, a controlled effect in which pre- to post-treatment PTS symptom changes accounted for symptom changes in the control condition was calculated. The overall uncontrolled effect of third wave therapies in reducing PTS symptoms was medium to large (Hedges' g = 0.88 [0.72-1.03]). Treatment type, use of intent-to-treat analysis, inclusion of exposure, and format moderated the uncontrolled effect, but treatment duration did not. The controlled effect of third wave therapies was small to large in size (Hedges' g = 0.50 [0.20-0.80]). Findings suggest that third wave therapies demonstrate enough promise in treating individuals with PTS symptoms to warrant further investigation. Implications and suggestions for future third wave research are discussed.