Prolonged periods of instability in terms of living environment can lead to a serious increase in mental health issues among disaster-affected individuals. The aim of this study was to assess long-term trends in mental health among adult residents in a nuclear-disaster-affected area.Methods:
Mail-based, self-administered questionnaire surveys were conducted three times (T1–T3), targeting all residents registered with the municipalities in the evacuation zone in Fukushima prefecture at the time of the disaster. Age-adjusted prevalences of the following were analyzed by sex: risk of psychological distress by the Kessler 6-item Scale, post-traumatic stress by the Post-traumatic Stress Disorder Checklist, and problem drinking by CAGE.Results:
The numbers of respondents and response rates were: 73 568, 40.7% (T1); 55 076, 29.9% (T2); and 46 386, 25.0% (T3). Compared with normal Japanese levels in non-disaster settings (4.7%), the prevalence of general psychological distress by Kessler 6-item Scale ≥ 13 was still high 3 years after the event in both men (11.4%) and women (15.8%). Although the age-adjusted prevalence of psychological distress and post-traumatic stress (Post-traumatic Stress Disorder Checklist ≥ 44) had decreased over time (from 19.0% [T1] to 17.8% [T3] for men, and from 25.3% [T1] to 23.3% [T3] for women), the age-adjusted prevalence of problem drinking (CAGE ≥ 2) remained steady in both men (20.7% [T2] and 20.4% [T3]; P = 0.18) and women (10.5% [T2] and 10.5% [T3]; P = 0.91).Conclusion:
Our results suggest that long-term interventions focused on post-traumatic stress as well as other mental health problems are strongly needed for disaster-affected individuals.