Paroxetine CR augmentation for posttraumatic stress disorder refractory to prolonged exposure therapy

Little is known about the efficacy of "next step" strategies for patients with post-traumatic stress disorder (PTSD) who remain symptomatic despite treatment. This study prospectively examines the relative efficacy of augmentation of continued prolonged exposure therapy (PE) with paroxetine CR versus placebo for individuals remaining symptomatic despite a course of PE.

Adult outpatients meeting DSM-IV criteria for PTSD were recruited from February 2003 to September 2005 at 4 academic centers. Phase I consisted of 8 sessions of individual PE over a 4- to 6-week period. Participants who remained symptomatic, defined as a score of >or= 6 on the Short PTSD Rating Interview (SPRINT) and a Clinical Global Impressions-Severity of Illness scale (CGI-S) score >or= 3, were randomly assigned to the addition of paroxetine CR or matched placebo to an additional 5 sessions of PE (Phase II).

Consistent with prior studies, the 44 Phase I completers improved significantly with initial PE (SPRINT: paired t = 7.6, df = 41, p < .0001; CGI-S: paired t = 6.37, df = 41, p < .0001). Counter to our hypothesis, however, we found no additive benefit of augmentation of continued PE with paroxetine CR compared to pill placebo for the 23 randomly assigned patients, with relatively minimal further gains overall in Phase II.

Although replication with larger samples is needed before definitive conclusions can be drawn, our data do not support the addition of paroxetine CR compared with placebo to continued PE for individuals with PTSD who remain symptomatic after initial PE, suggesting that the development of novel treatment approaches for PTSD refractory to PE is needed.

ClinicalTrials.gov identifier NCT00215163.