The Effect of Add-on Memantine in New Onset Combat-Related Posttraumatic Stress Disorder Core Symptoms: A Pilot Study

Objective: Studies using standard neuropsychological instrumentation have shown memory deficits in posttraumatic stress disorder (PTSD) patients. We examined the efficacy and safety of memantine in new cases of combat-related PTSD in the military by conducting a 16-week prospective double-blind randomized controlled trial. Method: Twenty-six new combat-related PTSD cases were recruited from among the military personnel based on the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5). Patients were assigned to memantine and Placebo groups. They were monitored at baseline, week eight, and week 16. Memantine was added to each patient s current medication with an initial dosage of 5 mg/day, raised by 5 mg/day every week until it reached the maintenance level of 20 mg/day. The concurrent drugs were essentially kept unchanged during the trial. The primary outcome was PTSD severity as assessed by the Clinician-administered PTSD Scale (CAPS). The CAPS is a valid and reliable tool for the diagnosis of PTSD and measurement of its severity according to the DSM-4. Results: CAPS mean score in baseline (P = 0.811) and weeks eight (P = 0.389) and 16 (P = 0.066) did not show any significant differences between the two groups. The mean CAPS score in the memantine group significantly (P = 0.006) decreased (Mean differences = -8.79) compared to the placebo group, showing that intervention with memantine was effective. The mean total CAPS in weeks eight (Mean differences = -14.21) and 16 (Mean differences = -27) were less than the baseline, which was significantly meaningful (P 0.001). Conclusion: Findings of this study suggest that add-on memantine can be effective in veteran patients with PTSD. So our data provide useful insight into the management of new cases of combat-related PTSD.