Premenstrual symptoms and posttraumatic stress disorder in Japanese high school students 9 months after the great East-Japan earthquake.

On March 11, 2011, the Great East-Japan Earthquake occurred and a massive tsunami hit the northeastern coast of Japan. Catastrophic disasters such as earthquakes and war cause tremendous damage, not only physically but also mentally. Posttraumatic stress disorder (PTSD) is an anxiety disorder that occurs in the aftermath of a traumatic event. Premenstrual syndrome (PMS) is a cluster of psychological and somatic symptoms that are limited to the late luteal phase of the menstrual cycle. Premenstrual dysphoric disorder (PMDD) is considered a severe form of PMS. To determine the relationship between premenstrual symptoms and natural disaster-induced PTSD among Japanese adolescent girls, we conducted a cross-sectional study. Overall, 1489 high school students who belong to two high schools in Sendai, the largest city in northeastern Japan, were assessed 9 months after the earthquake. These schools are located inland, far from the seashore, and were not damaged by the tsunami. Premenstrual symptoms were assessed using the Premenstrual Symptoms Questionnaire, and PTSD symptoms were assessed using the Japanese-language version of Impact of Event Scale-Revised, which is a widely used self-assessment questionnaire about PTSD symptoms. We analyzed the data of 1,180 girls who completed the questionnaires and 118 girls (10.0%) were classified as having PTSD. The prevalence rates of PMDD and moderate to severe PMS increased according to the comorbidity of PTSD (p < 0.001), showing a correlation between the severity of PMS/PMDD and natural disaster-induced PTSD. The comorbidity of PMS/PMDD and PTSD may complicate the follow-up of both conditions.