Long-term efficacy of psychotherapy for posttraumatic stress disorder: A meta-analysis of randomized controlled trials.

Psychotherapies are well established as efficacious acute interventions for posttraumatic stress disorder (PTSD). However, the long-term efficacy of such interventions and the maintenance of gains following termination is less understood. This meta-analysis evaluated enduring effects of psychotherapy for PTSD in randomized controlled trials (RCTs) with long-term follow-ups (LTFUs) of at least six months duration. Analyses included 32 PTSD trials involving 72 treatment conditions (N=2935). Effect sizes were significantly larger for active psychotherapy conditions relative to control conditions for the period from pretreatment to LTFU, but not posttreatment to LTFU. All active interventions demonstrated long-term efficacy. Pretreatment to LTFU effect sizes did not significantly differ among treatment types. Exposure-based treatments demonstrated stronger effects in the posttreatment to LTFU period (d=0.27) compared to other interventions (p=0.005). Among active conditions, LTFU effect sizes were not significantly linked to trauma type, population type, or intended duration of treatment, but were strongly tied to acute dropout as well as whether studies included all randomized patients in follow-up analyses. Findings provide encouraging implications regarding the long-term efficacy of interventions and the durability of symptom reduction, but must be interpreted in parallel with methodological considerations and study characteristics of RCTs.