Progression of Onset of Substance Use Disorders Among American Indian and First Nation Adolescents

The “Gateway Hypothesis” is one of the most frequently studied, commonly known models of adolescent substance use progression. Across hundreds of studies, the hypothesis is most frequently supported in studies with samples of early adolescents and indicates sequential development from licit (alcohol and cigarettes) substance use to illicit drugs; however, this pattern is not consistently found among diverse social, racial, and ethnic groups or among serious drug users. 

The focus of prior gateway hypothesis studies has centered upon patterns of substance use initiation. Much less attention has been devoted to the systematic progression of onset of substance use disorders (SUD). That is, do addictions proceed in a developmental sequence from dependence on licit substances such as nicotine and alcohol to more illicit drugs like marijuana? 

In this presentation we use eight waves of data from a panel study of Indigenous (U.S. American Indians and Canadian First Nations) adolescents who share a common culture to investigate patterns of onset of SUDs as the youth aged from early adolescence (mean = 11.1) years to early adulthood (mean = 18.3 years).    We report the results of hazard analysis for the emergence of nicotine, alcohol, and marijuana dependence within the sample. 

The findings provide evidence of temporal gateways from nicotine dependence to alcohol dependence, and in turn, marijuana dependence. This has important implications for prevention for the American Indian/First Nations communities in this study. Substance use preventions should begin very early and intensely target nicotine as a “gateway” drug.  Delaying or curtailing nicotine use not only may serve to reduce nicotine dependency, but may delay or reduce the emergence of later comorbid SUDs.