Cumulative adversity and drug dependence in young adults: racial/ethnic contrasts

Aims To study cumulative exposure to stressors as a risk factor for drug dependence, and evaluate whether group differences in exposure contribute to differences in prevalence. Design Cross‐sectional community survey of life‐time adverse experiences and substance and psychiatric disorders. Setting Data collected between 1997 and 2000 in Miami–Dade County, USA. Participants A total of 1803 former Miami–Dade public school students, 93% between ages 19 and 21 years when interviewed. Males and females of Cuban origin, other Caribbean basin Hispanics, African‐Americans and non‐Hispanic whites are represented equally. Measurements Drug dependence disorder assessed by DSM‐IV criteria using the Composite International Diagnostic Interview, and a 41‐item checklist of life‐time exposure to major and potentially traumatic experiences. Both measures include age at time of first occurrence. Findings Life‐time rate of drug dependence disorder (total 14.3%) did not vary significantly (P > 0.05) by socio‐economic group. Male rate (17.6%) was significantly greater than female rate (10.9%). The African‐American rate (6.5%) was dramatically lower than non‐Hispanic white (17.0%), Cuban (18.1%) and non‐Cuban Hispanic (16.0%) rates despite their dramatically higher exposure to adversity. Twenty‐eight of 33 individual adversities were associated with the subsequent onset of drug dependence (P < 0.05). Cumulative life‐time exposure was greatest for males and for African‐Americans, and was associated inversely with socio‐economic level. Multivariate discrete‐time event history analysis revealed significant independent effects of distal (>1 year earlier) and proximal (previous year) exposure to adverse events (P < 0.05), controlling for childhood conduct disorder, attention deficit hyperactive disorder and previous psychiatric disorder. Conclusions Life‐time cumulative exposure to distant as well as more recent adversity predicts risk of subsequent drug dependence, although it does not explain ethnic group differences in risk.