Initiation of alcohol, marijuana, and inhalant use by American-Indian and white youth living on or near reservations.

Background: Early initiation of drinking, intoxication, marijuana, and inhalant use is associated with negative outcomes and substance use trajectories. Using national datasets, American Indian (AI) youth have been found to initiate substance use earlier than other youth. This study uses a population-based sample of youth living on or near reservations to compare substance use onset for AI and white youth where socioeconomic conditions may be similar for these youth.

Methods: Student survey data were gathered from 32 schools in 3 regions from 2009 to 2012. A retrospective person-period data set was constructed using reported age of initiation of intoxication and marijuana and inhalant use. Multi-level modeling and event history analysis were used to estimate initiation as a function of age, gender, ethnicity, and region.

Results: The results provide further evidence that AI youth living on or near reservations initiate substance use significantly earlier than white youth who attend the same schools and live in the same communities. Differences between the two cultural groups were most evident for marijuana initiation where the odds of initiating marijuana use ranged from seven to 10 times greater for nine vs. eight-year-old AI compared to white youth.

Conclusions: Prevention efforts targeted to AI youth must begin earlier than for non-AI youth in order to delay or prevent initiation. In addition, better understanding about the differences in the psychosocial environments of AI and white youth living in these communities is of paramount importance in designing prevention efforts.