Treatment of Posttraumatic Stress Disorder Using the Traditional Japanese Herbal Medicine Saikokeishikankyoto: A Randomized, Observer-Blinded, Controlled Trial in Survivors of the Great East Japan Earthquake and Tsunami

The Great East Japan earthquake and tsunami caused immense damage over a wide area of eastern Japan. Hence, many survivors are at high risk for posttraumatic stress disorder (PTSD). This randomized, observer-blinded, controlled trial examined the efficacy and safety of the traditional Japanese herbal formula saikokeishikankyoto (SKK) in the treatment of PTSD among survivors of this disaster. Forty-three participants with an Impact of Event Scale-Revised (IES-R) score ≥ 25 were randomized into SKK (n = 21) and control (n = 22) groups. The primary endpoint was the change in IES-R scores from baseline till after 2 weeks of treatment. Intergroup statistical comparisons were performed. The magnitude of changes in total IES-R scores differed significantly between the two groups (P < 0.001). Post hoc analysis showed that the total IES-R score improved significantly in the SKK group from 49.6 ± 11.9 to 25.5 ± 17.0 (P < 0.001). Subscale scores improved significantly in the SKK group (avoidance, P = 0.003; hyperarousal, P < 0.001; intrusion, P < 0.001). Two-week treatment with SKK significantly improved IES-R scores among PTSD patients. This traditional medicine may be a valid choice for the treatment of psychological and physical symptoms in PTSD patients.