Longitudinal effects of disaster-related experiences on concern and its impact on depressive symptoms among Fukushima nuclear power plant workers: The Fukushima NEWS project study

Background The 2011 Fukushima nuclear disaster affected the mental health of nuclear plant workers. Objective The study aimed to explore the longitudinal relationship between workers' disaster-related experiences and concern, and the impact of concern on depressive symptoms over three years. Method A total of 1347 workers from Fukushima Daiichi and Daini nuclear power plants participated. Three types of concern (work, life, or health-related) and depressive symptoms were assessed from 2012 to 2014 using self-reporting concern questionnaires and the Center for Epidemiologic Studies Depression Scale (CES-D). The relationships between disaster-related experiences and concern and depressive symptoms (CES-D score >= 16) were analyzed using mixed-effects models, as were the associations between type of concern and depressive symptoms. Stratified analyses for all associations were performed according to work location in 2011. Results Each type of concern was associated with different disaster-related experiences. Depressive symptoms were associated with job-related concern (beta = 0.015, p < 0.011), life-related concern (beta = 0.018, p = 0.002), and health-related concern (beta = 0.018, p < 0.001), and these associations remained over two years. The associations were more evident in Daiichi plant workers, while Daini plant workers only exhibited significant associations with health-related concern. Conclusions Different disaster-related experiences affected plant workers' concern. The risk of depressive symptoms was significant among workers with any of the three types of concern, particularly for Daiichi plant workers. It is important to understand plant workers' concern and their experiences during the disaster to guide them towards mental health support and clinical interventions.