A Meta-Analysis of Interpersonal and Psychodynamic Psychotherapies for Posttraumatic Stress Disorder

Objective: Established trauma-focused cognitive-behavioral therapies for posttraumatic stress disorder (PTSD) have remission rates of approximately 30%-40%. Alternatively, interpersonal psychotherapy (IPT) and psychodynamic psychotherapy (PDT) focus on disrupted attachment, mentalization, and social connection in PTSD and may help some patients. The authors conducted a meta-analysis on these interpersonal and affect-oriented approaches to treating PTSD. Methods: Building on a prior meta-analysis, the authors searched for randomized controlled trials (RCTs) comparing IPT or PDT with other established PTSD treatments or control conditions for adults diagnosed as having PTSD. Random- effects meta-analyses were conducted to assess outcome effect sizes and dropout rates. RCTs were rated via the Randomized Controlled Trial Psychotherapy Quality Rating Scale. Results: Ten RCTs (eight of IPT) comparing IPT or PDT with control (k=7) or active treatment (k=4) conditions were identified, nine of which were of adequate quality. IPT (k=5) and PDT (k=2), when analyzed together, were superior to control conditions overall (g=-1.14, p= 0.011 [as was IPT alone: g=-0.88, p= 0.034]) and to waitlist (g=-1.49) and treatment-as-usual (g=-0.70) groups. Effect sizes, however, may have been inflated by outliers or publication bias. IPT (k= 3) and PDT (k= 1), when analyzed together, were equally efficacious compared with other active PTSD treatments (primarily exposure-based psychotherapies), as was IPT alone, and had lower dropout rates (relative risk= 0.63, p= 0.049 for IPT and PDT analyzed together; relative risk= 0.61, p= 0.098 for IPT alone). Conclusions: Affect-focused therapies hold promise in the treatment of PTSD. IPT has demonstrated efficacy in multiple trials, whereas the evidence base for PDT is sparse.