Objective: It has been suggested that the anticonvulsant drug pregabalin may be useful in some anxiety disorders. The goal of this study was to evaluate the effectiveness of pregabalin augmentation of standard treatment (selective serotonin reuptake inhibitors and sodium valproate) for patients with chronic posttraumatic stress disorder (PTSD).
Methods: This doubleblind, placebo-controlled clinical trial was conducted at Ibn-E-Sina Psychiatric Hospital (Mashhad, Iran) in 2013. Thirty-seven male patients diagnosed with combat-related PTSD based on DSM-IV-TR criteria were randomly assigned to two groups: 18 patients, the case group, received pregabalin (300 mg/day) while 19 patients, the control group, received placebo for 6 weeks. Assessments were done at baseline and at 2, 4, and 6 weeks after the onset of treatment, using the PTSD Check List-Military Version (PCL-M), the Hamilton Depression Rating Scale, the Hamilton Anxiety Rating Scale, and the Spitzer Quality of Life Index.
Results: Pregabalin was just significantly effective in improving PCL-M scores (p=0.045) in comparison to placebo. Although depression and anxiety scores diminished significantly in both groups (p=0.001 and 0.0001, respectively), comparison of the efficacy of pregabalin and placebo did not show significant differences in depression, anxiety, and quality of life scores (p=0.614, 0.144, and 0.076, respectively).
Conclusion: Pregabalin effectively reduced the severity of PTSD symptoms but it was not effective in improving the severity of depression, anxiety, and quality of life. Further investigations are required to confirm or refute these findings.