Paroxetine in the Treatment of Chronic Posttraumatic Stress Disorder: Results of a Placebo-Controlled, Flexible-Dosage Trial

Background: The objective of this double-blind, placebo-controlled study was to investigate the efficacy and safety of paroxetine in outpatients with posttraumatic stress disorder (PTSD).

Method: Male and female outpatients 18 years and older who met DSM-IV criteria for PTSD and had baseline scores of 50 or greater on the Clinician Administered PTSD Scale (CAPS-2) were randomly assigned to treatment with paroxetine (20-50 mg/day) or placebo for 12 weeks. The primary efficacy variables were the change from baseline to the 12-week endpoint in the CAPS-2 total score and the proportion of responders on the Clinical Global Impressions-Global Improvement scale (CGI-I). Additional key outcome measures were the change from baseline in the reexperiencing, avoidance/numbing, and hyperarousal scores of the CAPS-2 and in the total scores of the Treatment Outcome PTSD Scale and the patient-rated Davidson Trauma Scale and Sheehan Disability Scale (SDS). Depressive symptoms were assessed with the Montgomery-Asberg Depression Rating Scale. The proportion of patients achieving response and remission was also determined.

Results: 307 patients constituted the intent-to-treat population. At week 12, compared with the placebo group (N = 156), the paroxetine group (N = 151) showed significantly greater reduction of PTSD symptoms on both of the primary and all of the secondary outcome measures. Significantly greater improvement on the CAPS-2 total score was observed for paroxetine compared with placebo from week 4 (p < .05), and significantly greater proportions of paroxetine-treated patients achieved response (p < .001) and remission (p = .008) by week 12. The improvement in PTSD symptoms was similar in male and female patients. Functional improvement at the study endpoint was significantly greater (p < .05) in the paroxetine group in all 3 domains of the SDS (work, social life, family life). Treatment with paroxetine was well tolerated, with the frequency and type of adverse events recorded for the paroxetine group corresponding to the known safety profile of this medication.

Conclusion: Paroxetine in doses of 20 to 50 mg once daily is effective as a treatment for chronic PTSD. Improvement is obtained for all 3 symptom clusters (reexperiencing, avoidance/numbing, hyperarousal) and is associated with significant reduction in disability after 12 weeks of treatment.