Dopamine-Altering Medication Use Is Associated with Immune and Sickness-Related Outcomes: A Sex-Stratified Population-Based Study

Background/Objectives: Dopaminergic signaling regulates immune-cell activity in experimental models, but its association with immune-related outcomes in human populations remains unclear. We examined whether use of dopamine (DA)-altering medications was associated with immune-related symptoms, systemic inflammatory biomarkers, and recent health-related activity limitation. Methods: We analyzed National Health and Nutrition Examination Survey data from 53,585 participants aged 16–65 years. Primary analyses compared users of any DA-altering medication with nonusers. Secondary analyses distinguished medications expected to increase or decrease dopaminergic signaling. Outcomes included self-reported colds, infections, and days of reduced usual activity due to health problems in the preceding 30 days, as well as C-reactive protein (CRP) and white blood cell (WBC) counts. We also conducted sex-stratified and sensitivity analyses. Results: DA-altering medication use was associated with greater odds of recent health-related activity limitation (odds ratio 3.38, 95% confidence interval 2.94–3.90), higher CRP (+40.2%), and higher WBC counts (+4.0%) compared with nonuse. Associations with recent colds and infections were not statistically significant in the overall primary analysis. In secondary analyses, DA-decreasing medication use was associated with lower odds of recent colds among males and higher odds of infections among females, and health-related activity limitation and inflammatory biomarker associations were generally stronger for DA-decreasing medications. Elevated CRP and associations with health-related activity limitation persisted in analyses excluding participants with depressive symptoms and mental health-related activity limitation. Conclusions: DA-altering medication use was associated with systemic inflammatory biomarkers and recent health-related activity limitation. Longitudinal studies are needed to determine whether these associations reflect medication effects, underlying treatment indications, or both.