Physiological Determinants of Chronic Stress in Relation to Substance Use and Neighborhood Crime

Background: African Americans (AAs) are more likely to report greater levels of perceived stress (PSS) and are susceptible to suffering from chronic stress and the related negative outcomes due to poorer environments that they live in and daily stressors they experience due to racism, discrimination, socioeconomic status, and neighborhood crime. Methods: Participants (N=241; Mage=20.43, 72.03% female) were administered measures including self-reported neighborhood violence, substance use, and PSS. Study procedures included the provision of seven saliva samples for cortisol analysis (at wakeup, 30 and 90 minutes post-wakeup, 1:00PM, 2:30PM, 4:00PM, and pre-bedtime). Five measures of the repeated measures of cortisol awakening response (CAR) were computed for each individual. The measures using Area Under the cortisol Curve (i.e., AUC0, AUC1, and AUC7) were calculated by the trapezoid formula. Results: PSS was significantly negatively related to AUC0 (p=0.020) and Cortisolmean (p=0.017), while daily alcohol use was positively correlated with AUC7 (p=0.046). The results of multiple regression analyses showed that PSS was a significant negative predictor for AUC0 (p=0.020) and Cortisolmean (p=0.017), daily drinking amount was a significant positive predictor (p=0.040) for AUC7 after controlling for age and sex. Discussion: As levels of PSS increased, the AUC and overall cortisol levels decreased. This association suggests those who experience high levels of PSS likely become ‘resilient’ to their environmental stressors that influence increased cortisol production. In addition, daily alcohol use was associated with an increase in pre-bedtime cortisol levels, suggesting that excessive alcohol consumption, likely near the individuals’ bedtime, influences stress symptomology and cortisol production.