Autonomic Nervous System Reactivity and Addiction Vulnerability in the African American Community

Background: African Americans experience disproportionate rates of morbidity and mortality with regard to drug use, but the mechanisms underlying this association remain poorly understood. Increasing evidence suggests that exposure to chronic stress and the subsequent activation of the physiological stress systems have been linked to the development of addiction. To date, no research exists that focuses on the influence of autonomic reactivity on prospective drug use among African American emerging adults. Purpose: The present study aimed to: (1) investigate the association between ANS reactivity and prospective drug use among a sample of African American emerging adults (18-25 years old) in the southwestern U.S.; (2) characterize the impact of chronic environmental stress exposure on regulatory mechanisms of the ANS; and (3) identify socially- and culturally-specific risk and resilience factors associated with physiological stress reactivity in this population. Methods: Participants (N = 277) were assessed across three different time points over a period of four-months. They completed measures of self-reported chronic and race-related stress exposure, behavioral and emotional coping styles, and past 90-day marijuana and alcohol use. They also underwent a laboratory-based stressor to derive measures of autonomic reactivity to acute stress, including heart rate (HR), heart rate variability (HRV), and skin conductance levels (SCL). Results: Higher SCL reactivity to acute stress was associated with higher rates of subsequent alcohol and marijuana use at 90-day follow-up. There was no significant association between autonomic reactivity and chronic, nor race-related stress exposure. However, there was a significant interaction effect, such that active coping moderated the relationship between race-related stress exposure and HRV reactivity to acute stress. Conclusions: These results highlight the role of ANS (dys)regulation as a putative link between environmental stress exposure and subsequent drug use vulnerability among African American emerging adults.