Long-term exposure to methylmercury and psychiatric symptoms in residents of Minamata, Japan

► We examined association between methylmercury and psychiatric symptoms in Minamata. ► The data demonstrated higher prevalence of psychiatric symptoms in Minamata. ► Participants with psychiatric symptoms in Minamata more often had neurological signs. ► There were peaks in the prevalence around age 20 and in older adults in Minamata. ► These findings did not change when we excluded officially certified patients.