Trajectories of peer relationship problems and emotional symptoms in children 5 years after a nuclear disaster: Fukushima Health Management Survey.

The Fukushima Daiichi Nuclear Power Station (NPS) accident, which occurred in March 2011, is having long-term effects on children. About 3 years after the accident, we identified three patterns of peer relationship problems and four patterns of emotional symptoms using group-based trajectory modeling. As a result, we reported that different factors might be related to very severe trajectories of peer relationship problems and emotional symptoms. In this study, we used five waves of data from fiscal year (FY) 2011 to FY2015 from the Mental Health and Lifestyle Survey, a detailed survey of the Fukushima Health Management Survey started in FY2011. We analyzed 7013 residents within the government-designated evacuation zone (aged 6-12 years old as of 11 March 2011) with responses to all items of psychological distress in at least one wave from FY2011 and FY2015. We planned this study to describe the trajectories of peer relationship problems and emotional symptoms in children and to examine potential risks and protective factors over the 5 years following the NPS accident. We identified four patterns of peer relationship problems and five patterns of emotional symptoms using latent class growth analysis. For peer relationship problems, male sex, experiencing the NPS explosion and lack of exercise habits were associated with the severe trajectory group. For emotional symptoms, experiencing the NPS explosion, experiencing the tsunami disaster and lack of exercise habits were associated with the severe trajectory group. Exercise habits are very important for the mental health of evacuees after a nuclear disaster.