Background: Distrust in authorities has negative effects on mental health. Aims: In this study, we aimed to explore whether the impact of distrust in government on mental health became stronger in the area heavily affected by the 2011 Fukushima nuclear power plant accident. Methods: We examined the effects of distrust in the national government on depressive symptoms three years after the accident among community residents in Fukushima prefecture using those in the Kanto area (the area surrounding Tokyo) as a control. A questionnaire survey was administered to a random sample of 1000 residents in Fukushima prefecture and 1650 residents in the Kanto area. Distrust in the national government was assessed using a four-point single-item scale. Depressive symptoms were measured using the Patient Health Questionnaire-9. The associations of residential area (i.e. living in Fukushima prefecture or in the Kanto area) and distrust in the national government with depressive symptoms were examined, controlling for socio-demographic characteristics and disaster-related experiences using multivariate linear regression analyses. We used the interaction term of residential area and distrust in the government to explore the difference in the association between the respondents in Fukushima prefecture and those in the Kanto area. Results: Valid responses were obtained from 976 (36.8%) residents. Distrust in the government was associated with depressive symptoms and the association was stronger in Fukushima prefecture than in the Kanto area. Conclusion: The deleterious effects of distrust in the government on mental health may become more serious after a nuclear power plant accident and require careful attention during support activities in an affected area.