RESUMO
BACKGROUND: Childhood abuse and homelessness are independently associated with substance use. Though childhood abuse and homelessness are strongly correlated, research on the joint effect of exposure to both traumatic life events on substance use is limited. Objective: To estimate independent and joint effects of childhood abuse and homelessness on substance use risk during emerging adulthood and adulthood. Methods: Using the National Longitudinal Study of Adolescent to Adult Health (N = 12,288), we measured associations between exposure to physical or sexual abuse in childhood, homelessness in childhood or emerging adulthood, or exposure to both traumas and outcomes of binge drinking, marijuana use, cocaine use, methamphetamine use, and prescription opioid misuse during emerging adulthood (Wave III, ages 18-26 years) and adulthood (Wave IV, ages 24-32 years). Results: In adjusted analyses, exposure to childhood abuse alone, homelessness alone, and both childhood abuse and homelessness were significant correlates of most substance use indicators in emerging adulthood. Those jointly exposed to childhood abuse and homelessness had disproportionate risk of substance use, particularly use of cocaine (adjusted odds ratio (AOR)=4.25, 95% confidence interval (CI): 2.70, 6.71) and methamphetamine (AOR = 6.59, 95% CI: 3.87, 11.21). The independent and combined effects of abuse and homelessness generally persisted into adulthood though associations tended to weaken. Conclusions/Importance: Those with exposure to abuse, homelessness, and both adverse outcomes constitute a high-risk population for substance use. Addressing abuse and homelessness should be a component of preventing drug risk for screening, treatment, and prevention efforts.