Influence of risk and protective factors on substance use outcomes across developmental periods: a comparison of youth and young adults.

Data were collected from samples of youth (ages 11-18; N = 38,268) and young 10 adults (ages 18-24; N = 602) across 30 Tennessee counties using surveys and telephone interviews conducted in 2006-2008. Data were analyzed using hierarchical nonlinear modeling to determine: (1) which risk and protective factors predicted alcohol and marijuana use, and (2) whether predictors differed as a function of developmental period. Findings provide preliminary evidence that prevention efforts need to take into consideration the changing environment and related influences as youth age, especially as they move from a more protected community environment to one where they live somewhat independently. Implications and limitations are discussed.