Objective: We explored associations between psychiatric history and cognitive functioning, and differences by sex and race/ethnicity (SRE) in 20,155 Health and Retirement Study (1995-2014) participants aged 65 or older. Methods: Multi-level growth curve models examined cognition scores and their trajectories over time by SRE. Results: A history of psychiatric, emotional, or nervous problems was significantly related to cognition scores and rates of decline. Hispanic and Black participants had significantly lower cognition scores at age 75 and steeper rates of decline than White females, and Black race and the Hispanic race/ethnicity-sex interaction erased the protective effects of being female. Conclusions: Future research should include specific psychiatric diagnoses. Population level findings as reported here, along with aggregate findings from similar studies, can inform interventions and policies regarding support for populations that are vulnerable to mental illness and to subsequent cognitive decline.