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

Objective: This was a 12-week randomized, placebo-controlled trial to assess the efficacy of quetiapine monotherapy in the treatment of posttraumatic stress disorder (PTSD). Method: Eighty patients were randomly assigned to treatment with either quetiapine or placebo. The primary outcome measure was the Clinician-Administered PTSD Scale (CAPS). Secondary efficacy measures included the CAPS subscales, the Davidson Trauma Scale, the Positive and Negative Syndrome Scale (PANSS), the Clinical Global Impressions (CGI) scales for severity of Illness and improvement, the Hamilton Depression Rating Scale (HAM-D), and the Hamilton Anxiety Rating Scale (HAM-A). Safety measurements included adverse events, vital signs, the Abnormal Involuntary Movement Scale, the Barnes Akathisia Scale, the Simpson-Angus Scale, and the Arizona Sexual Experiences Scale. Results: After a 1-week placebo run-in, quetiapine was started at a daily dosage of 25 mg and increased to a maximum of 800 mg; the average was 258 mg (range, 50-800 mg). Reductions in CAPS total, re-experiencing, and hyperarousal scores were significantly greater for the quetiapine group than for the placebo group. Greater improvements were also observed for quetiapine in scores on the Davidson Trauma Scale, CGI severity and improvement ratings, PANSS positive symptom and general psychopathology subscales, HAM-A, and HAM-D than for placebo. Adverse events were generally mild and expected based on prior studies of quetiapine in this and other patient population. There were no differences in safety measures between groups. Conclusion: Quetiapine monotherapy was efficacious in the treatment of PTSD. These findings suggest quetiapine as a single agent is effective in treating military PTSD.