BackgroundMajor depression is associated with significant disability, morbidity, and mortality. The current study estimated trends in the prevalence of major depression in the US population from 2005 to 2015 overall and by demographic subgroups.MethodsData were drawn from the National Survey on Drug Use and Health (NSDUH), an annual cross-sectional study of US persons ages 12 and over (total analytic sample N = 607 520). Past-year depression prevalence was examined annually among respondents from 2005 to 2015. Time trends in depression prevalence stratified by survey year were tested using logistic regression. Data were re-analyzed stratified by age, gender, race/ethnicity, income, and education.ResultsDepression prevalence increased significantly in the USA from 2005 to 2015, before and after controlling for demographics. Increases in depression were significant for the youngest and oldest age groups, men, and women, Non-Hispanic White persons, the lowest income group, and the highest education and income groups. A significant year × demographic interaction was found for age. The rate of increase in depression was significantly more rapid among youth relative to all older age groups.ConclusionsThe prevalence of depression increased significantly in the USA from 2005 to 2015. The rate of increase in depression among youth was significantly more rapid relative to older groups. Further research into understanding the macro level, micro level, and individual factors that are contributing to the increase in depression, including factors specific to demographic subgroups, would help to direct public health prevention and intervention efforts.