Objective: The authors assessed the efficacy of trauma memory reactivation performed under the influence of propranolol, a noradrenergic beta-receptor blocker, as a putative reconsolidation blocker, in reducing symptoms of posttraumatic stress disorder (PTSD).
Method: This was a 6-week, double-blind, placebo-controlled, randomized clinical trial in 60 adults diagnosed with long-standing PTSD. Propranolol or placebo was administered 90 minutes before a brief memory reactivation session, once a week for 6 consecutive weeks. The hypothesis predicted a significant treatment effect of trauma reactivation with propranolol compared with trauma reactivation with placebo in reducing PTSD symptoms on both the Clinician-Administered PTSD Scale (CAPS) and the patient-rated PTSD Checklist-Specific (PCL-S) in an intention-to-treat analysis.
Results: The estimated group difference in posttreatment CAPS score, adjusted for pretreatment values (analysis of covariance), was a statistically significant 11.50. The within-group pre- to posttreatment effect sizes (Cohen's d) were 1.76 for propranolol and 1.25 for placebo. For the PCL-S, the mixed linear model's estimated time-by-group interaction yielded an average decrease of 2.43 points per week, for a total significant difference of 14.58 points above that of placebo. The pre- to posttreatment effect sizes were 2.74 for propranolol and 0.55 for placebo. Per protocol analyses for both outcomes yielded similar significant results.
Conclusions: Pre-reactivation propranolol, a treatment protocol suggested by reconsolidation theory, appears to be a novel and efficacious treatment for PTSD. Replication studies using a long-term follow-up in various trauma populations are required.
Trial registration: ClinicalTrials.gov NCT01127568.
Keywords: Memory; Post-Traumatic; Propranolol; Randomized Controlled Trial; Stress Disorders; Therapeutics.