ObjectiveTo study the effects of recent political events on mood among young physicians.DesignProspective cohort study.SettingUnited States medical centres.Participants2345 medical interns provided longitudinal mood data as part of the Intern Health Study between 2016 and 2018.Main outcome measuresMean mood score during the week following influential political and non-political events as compared with mean mood during the preceding four week control period.ResultsWe identified nine political events and eight non-political events for analysis. With the start of internship duties in July, the mean decline in mood for interns was −0.30 (95% confidence interval −0.33 to −0.27, t=−17.45, P<0.001). The decline in mood was of similar magnitude following the 2016 presidential election (mean mood change −0.32, 95% confidence interval −0.45 to −0.19, t=−4.73, P<0.001) and subsequent inauguration (mean mood change −0.25, 95% confidence interval −0.37 to −0.12, t=−3.93, P<0.001). Further, compared with men, women reported greater mood declines after both the 2016 election (mean gender difference 0.31, 95% confidence interval 0.05 to 0.58, t=2.33, P=0.02) and the inauguration (mean gender difference 0.25, 95% confidence interval 0.01 to 0.49, t=2.05, P=0.04). Overall, there were statistically significant changes in mood following 66.7% (6/9) of political events assessed. In contrast, none of the non-political events included in the analysis were statistically significantly associated with a change in mood.ConclusionsMacro level factors such as politics may be correlated with the mood of young doctors. This finding signals the need for further evaluation of the consequences of increasing entanglement between politics and medicine moving forward for young physicians and their patients.