Three‐year trend survey of psychological distress, post‐traumatic stress, and problem drinking among residents in the evacuation zone after the Fukushima Daiichi Nuclear Power Plant accident [The Fukushima Health Management Survey]

Aim 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.