Pubertal Development and the Onset of Substance Use Among Appalachian Youth: A Longitudinal Study.

: We investigated the links between pubertal timing and tempo and the onset of cannabis, alcohol, and tobacco use among middle schoolers in Appalachian communities. : School surveys were administered to middle school students of the 6th grade and continuing through the spring of the 8th grade ( = 2,587; 49.4% boys), beginning in the fall at six-month intervals. Youth self-reported on their pubertal development and substance use. We examined the influence of baseline levels and rate of growth in puberty as predictors of substance use onset with Latent Growth Curve Modeling (LGCM), stratified by sex/gender. : Our findings show that early pubertal timing was associated with an increased likelihood for onset of cannabis and alcohol use for boys, but not girls; pubertal tempo was not associated with onset. : Early pubertal development may be a risk factor for early-onset substance use for boys. Prevention programming beginning in the first year of middle school is recommended.