Online racism and substance use in Asian American/Pacific Islander/Native Hawaiian and Black American emerging adults.

Background: Emerging research suggests online racial discrimination may be related to alcohol use and smoking, though more studies are needed to clarify the associations in diverse populations.Objectives: To explore the associations between online racism and hazardous drinking, smoking status, and co-use among Black, Asian American/Native Hawaiian/Pacific Islander (AANHPI), and Multiracial "Generation Z" emerging adults.Methods: Emerging adults (2,801 Black American AANHPI and Multiracial; 49.3% female) were recruited via online quota-based sampling. Multivariable logistic regression models examined the association between online racism and substance use, adjusting for frequency of social media use, total internet use, and sociodemographic covariates. The Karlson - Holm - Breen method was used to examine the role of depression and anxiety.Results: Among Black emerging adults, online racism was associated with greater odds of substance use (OR = 1.04, p < .001) and current smoking (OR = 1.04, p = .001). A similar pattern emerged for AANHPI (hazardous drinking: OR = 1.05, p < .001), current smoking (OR = 1.06, p < .001), and co-use (OR = 1.07, p < .001), and multiracial (current smoking: OR = 1.06, p = .014; and co-use OR = 1.07, p = .003). Anxiety had more pronounced mediating associations for Black emerging adults, while depression had more pronounced mediating effects for AANHPI and multiracial emerging adults.Conclusion: The widespread and chronic nature of online racism may in aggregate negatively impact substance use at the population level. Addressing online racism may require coordinated action, with future directions including the development of accountability strategies, coping interventions, and affirming digital spaces.