Figure 1: Normally treated with therapy, new medicinal treatments for PTSD are showing to be effective, giving hope to sufferers of a relentless disorder.

Efficacy of Quetiapine Monotherapy in Posttraumatic Stress Disorder: A Randomized, Placebo-Controlled Trial

Ericka Berman


Posttraumatic Stress Disorder (PTSD) is a debilitating illness affecting approximately 7.8% of people in the U.S. over the course of their lifetime. As of now, two medications are approved in the U.S. to treat PTSD, but both treatments have limited success. Characteristics of the antipsychotic medication quetiapine suggest it may be helpful in treating PTSD symptoms of re-experiencing trauma and hyperarousal. Dr. Gerardo Villarreal and his team of researchers hypothesized that quetiapine would reduce severity of these symptoms.

Participants met PTSD criteria according to the Diagnostic and Statistic Manual of Mental Disorders, 4th Edition (DSM-IV). Veterans ranging in ages 18-65 were administered the Clinician-Administered PTSD Scale Diagnostic Version for DSM-IV (CAPS-DX). Eligible participants (N=47) received a 1-week placebo. They were then randomly assigned using a computer program to take quetiapine or a placebo. Participants were given their respective medication for a trial of 12 weeks and then evaluated at weeks 1, 2, 4, 8, and 12. Initially, a dose of 25 milligrams was given at bedtime, which gradually increased to 400 milligrams daily at the end of week 2.

The quetiapine group scored significantly lower CAPS-DX re-experiencing and hyperarousal scores (p=0.0004 and p=0.007 respectively) than that of the placebo group. However, these symptoms were the only ones that improved due to the use of quetiapine; other symptoms were not affected.

The significant improvement in CAPS scores suggests quetiapine could be beneficial treatment for PTSD patients. This is particularly important given the serious and difficult-to-treat nature of the disorder. Further research could expand on the length of the trials to see how efficacy of the drug changes with increased dosage and time.



  1. G. Villarreal et al., Efficacy of quetiapine monotherapy in posttraumatic stress disorder: a randomized, placebo-controlled trial. The American Journal of Psychiatry 173, 1205-1212 (2016). doi: 10.1176/appi.ajp.2016.15070967.
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