Generalizability of Pharmacologic and Psychotherapy Clinical Trial Results for Posttraumatic Stress Disorder to Community Samples

Objective: The present study sought to quantify the generalizability of pharmacologic and psychotherapy clinical trial results in individuals with a DSM-IV diagnosis of posttraumatic stress disorder (PTSD) to a large representative community sample.

Methods: Data were derived from the 2004-2005 National Epidemiologic Survey on Alcohol and Related Conditions (NESARC), a large nationally representative sample of the adult US population. We applied a standard set of exclusion criteria representative of pharmacologic and psychotherapy clinical trials to all adults with a DSM-IV diagnosis of PTSD in the previous 12 months (n = 1,715) and then to a subsample of participants seeking treatment (n = 366). Our aim was to assess how many participants with PTSD would fulfill typical eligibility criteria.

Results: We found that more than 6 of 10 respondents from the overall PTSD sample and more than 7 of 10 respondents seeking treatment for PTSD would have been excluded by 1 exclusion criterion or more in a typical pharmacologic trial. In contrast, about 2 of 10 participants in the full sample and about 3 of 10 participants seeking treatment for PTSD would have been excluded in a typical psychotherapy efficacy trial.

Conclusions: We found that psychotherapy trial results may be applied to most patients with PTSD in routine clinical practice. The designers of pharmacologic clinical trials should carefully consider the trade-offs between the application of each exclusion criterion and its impact on representativeness. Specification a priori of the goals of the study, better justification for each exclusion criterion, and estimation of the proportion of individuals ineligible for the trial would assist study design. Developing integrated forms of pharmacotherapy and psychotherapy that simultaneously target commonly overlapping psychiatric disorders may yield more informative results for mental health care providers and research funding agencies.