Objective: We examined the relationship of childhood exposure to adversity and risk of substance-use disorder in two culturally distinct American Indian reservation communities, exploring both the role of early initiation of substance use in mediating this relationship and variation in risk across types of adversity exposure.
Method: The American Indian Service Utilization, Psychiatric Epidemiology, Risk and Protective Factors Project provided data from 2,927 American Indians on the occurrence and age at onset of adversities, substance use, and substance-use-disorder symptoms.
Results: The risk of substance-use disorder associated with early adversity was explained partially by early initiation of substance use. Three types of adversity (major childhood events, traumas, and witnessed violence) were associated with early onset of substance use and increased risk of substance-use disorder. Gender and tribe were also related to variation in both early substance use and substance-use disorder.
Conclusions: Early exposure to adverse events was associated with early substance use and the subsequent development of substance-use disorders among American Indians. public health initiatives targeting substance use and substance-use disorders in American Indian communities should include efforts to help children in these communities cope with adversities they encounter.