A meta-analytic review of prolonged exposure for posttraumatic stress disorder

https://doi.org/10.1016/j.cpr.2010.04.007Get rights and content

Abstract

Two decades of research demonstrate the efficacy of exposure therapy for posttraumatic stress disorder (PTSD). The efficacy of prolonged exposure (PE), a specific exposure therapy program for PTSD that has been disseminated throughout the world, has been established in many controlled studies using different trauma populations. However, a meta-analysis of the effectiveness of PE for PTSD has not been conducted to date. The purpose of the current paper is to estimate the overall efficacy of PE for PTSD relative to adequate controls. We included all published randomized controlled trials of PE vs. control (wait-list or psychological placebo) for the treatment of PTSD in adolescents or adults. Treatments were classified as PE if they included multiple sessions of imaginal and in vivo exposure and were based on the manualized treatment developed by Foa, Rothbaum, Riggs, and Murdock (1991). Thirteen studies with a total sample size of 675 participants met the final inclusion criteria. The primary analyses showed a large effect for PE versus control on both primary (Hedges's g = 1.08) and secondary (Hedges's g = 0.77) outcome measures. Analyses also revealed medium to large effect sizes for PE at follow-up, both for primary (Hedges's g = 0.68) and secondary (Hedges's g = 0.41) outcome measures. There was no significant difference between PE and other active treatments (CPT, EMDR, CT, and SIT). Effect sizes were not moderated by time since trauma, publication year, dose, study quality, or type of trauma. The average PE-treated patient fared better than 86% of patients in control conditions at post-treatment on PTSD measures. PE is a highly effective treatment for PTSD, resulting in substantial treatment gains that are maintained over time.

Section snippets

Study selection

We selected well-controlled randomized trials of PE for PTSD using a comprehensive search strategy. We searched the following databases: PsycINFO (1840 to March 2009), MEDLINE (1966 to March 2009), Scopus (1869 to March 2009), and the Cochrane Central Register of Controlled Trials up to March 2009. The searches included the following terms: “prolonged exposure,” “cognitive behavioral,” “clinical trial,” “random,” “randomly,” “randomize,” “randomise,” “randomized,” or “randomised” alone and in

Results

Hypothesis 1

PE will outperform the control conditions on primary outcome measures at post-treatment.

This analysis included 13 studies with 675 participants. Consistent with prediction, prolonged exposure outperformed control conditions on primary outcome measures at posttreatment showing a large effect size (Hedges's g = 1.08 [SE = 0.20, 95% CI: 0.69 to 1.46, p < 0.001)]). Thus, the average participant receiving prolonged exposure fared better than 86% of the control participants at posttreatment on primary

Heterogeneity

A heterogeneity analysis was conducted to test the assumption that the effect sizes were from a homogeneous sample (Hedges & Olkin, 1985). For this analysis all 13 studies were included with all time points (post-treatment and follow-up) on primary outcome measures. The test was significant, Q(12) = 59.90, p < 0.001, suggesting that the random effects analyses were most appropriate for this study.

Moderators: effect size as a function of publication year, dose, type of trauma, and time since trauma

The following analyses were completed using unrestricted maximum likelihood meta regressions. There was

Major findings

This meta-analysis of 13 (N = 658) randomized controlled PE trials generally supported the hypotheses. As predicted, PE performed significantly better than control conditions on measures of PTSD both at post-treatment (g = 1.08) as well as at follow-up (g = 0.68). Similarly, PE treatment was associated with significantly better outcomes on secondary outcome measures, both at post-treatment (g = 0.77) and at follow-up (g = 0.41). These effect sizes compare quite favorably to those of other empirically

Acknowledgement

The authors thank Jaclyn L. Bolno for her generous assistance with the literature review.

References (55)

  • Bisson, J., & Andrew, M. (2007). Psychological treatment of post-traumatic stress disorder (PTSD). Cochrane Database of...
  • J.I. Bisson et al.

    Psychological treatments for chronic post-traumatic stress disorder: Systematic review and meta-analysis

    British Journal of Psychiatry

    (2007)
  • M. Borenstein et al.

    Introduction to meta-analysis

    (2007)
  • M. Borenstein et al.

    Comprehensive meta-analysis, a computer program for research synthesis

    (1999)
  • R. Bradley et al.

    A multidimensional meta-analysis of psychotherapy for PTSD

    American Journal of Psychiatry

    (2005)
  • R.A. Bryant et al.

    A randomized controlled trial of exposure therapy and cognitive restructuring for posttraumatic stress disorder

    Journal of Consulting and Clinical Psychology

    (2008)
  • R.A. Bryant et al.

    Imaginal exposure alone and imaginal exposure with cognitive restructuring in treatment of posttraumatic stress disorder

    Journal of Consulting and Clinical Psychology

    (2003)
  • M. Cloitre et al.

    Skills training in affective and interpersonal regulation followed by exposure: A phase-based treatment for PTSD related to childhood abuse

    Journal of Consulting and Clinical Psychology

    (2002)
  • J. Cohen

    Statistical power analysis for the behavioral sciences

    (1988)
  • J. Difede et al.

    A randomized controlled clinical treatment trial for World Trade Center attack-related PTSD in disaster workers

    Journal of Nervous and Mental Disease

    (2007)
  • J.A. Fairbank et al.

    Posttraumatic stress disorder

  • E.B. Foa et al.

    A comparison of exposure therapy, stress inoculation training, and their combination for reducing posttraumatic stress disorder in female assault victims

    Journal of Consulting and Clinical Psychology

    (1999)
  • E.B. Foa et al.

    Randomized trial of prolonged exposure for posttraumatic stress disorder with and without cognitive restructuring: `utcome at academic and community clinics

    Journal of Consulting & Clinical Psychology

    (2005)
  • E.B. Foa et al.

    Effective treatments for PTSD: Practice guidelines from the International Society for Traumatic Stress Studies

    (2009)
  • E.B. Foa et al.

    Treatment of posttraumatic stress disorder in rape victims: A comparison between cognitive-behavioral procedures and counseling

    Journal of Consulting and Clinical Psychology

    (1991)
  • Gilboa-Schechtman, E., Foa, E. B., Shafran, N., Aderka, I. M., Powers, M. B., Rachamim, L., Rosenbach, L., Yadin, E., &...
  • S.M. Glynn et al.

    A test of behavioral family therapy to augment exposure for combat-related posttraumatic stress disorder

    Journal of Consulting and Clinical Psychology

    (1999)
  • Cited by (697)

    View all citing articles on Scopus
    View full text