Inclusion and exclusion criteria in randomized controlled trials of psychotherapy for PTSD

Posttraumatic stress disorder (PTSD) is a prevalent and often disabling condition. Fortunately, effective psychological treatments for PTSD are available. However, research indicates that these treatments may be underutilized in clinical practice. One reason for this underutilization may be clinicians' unwarranted exclusion of patients from these treatments based on their understanding of exclusion criteria used in clinical trials of psychological treatments for PTSD. There is no comprehensive and up-to-date review of inclusion and exclusion criteria used in randomized clinical trials (RCTs) of psychological treatments for PTSD. Therefore, our objective was to better understand how patients were excluded from such RCTs in order to provide guidance to clinicians regarding clinical populations likely to benefit from these treatments.

We conducted a comprehensive literature review of RCTs of psychological treatments for PTSD from January 1, 1980 through April 1, 2012. We categorized these clinical trials according to the types of psychotherapy discussed in the major guidelines for treatment of PTSD and reviewed all treatments that were studied in at least two RCTs (N=64 published studies with 75 intervention arms since some studies compared two or more interventions). We abstracted and tabulated information concerning exclusion criteria for each type of psychotherapy for PTSD.

We identified multiple RCTs of cognitive behavioral therapy (n=56), eye movement desensitization and reprocessing (n=11), and group psychotherapy (n=8) for PTSD. The most common exclusions were psychosis, substance abuse and dependence, bipolar disorder, and suicidal ideation. Clinical trials varied in how stringently these criteria were applied. It is important to note that no exclusion criterion was used in all studies and there was at least one study of each type of therapy that included patients from each of the commonly excluded groups. A paucity of evidence exists concerning the treatment of patients with PTSD and four comorbidities: alcohol and substance abuse or dependence with current use, current psychosis, current mania, and suicidal ideation with current intent.

Psychological treatments for PTSD have been studied in broad and representative clinical populations. It appears that more liberal use of these treatments regardless of comorbidities is warranted.