Gender differences in the developmental risk of onset of alcohol, nicotine, and marijuana use and the effects of nicotine and marijuana use on alcohol outcomes.

OBJECTIVE: This study aimed to (a) characterize gender-specific risk of onset of alcohol, nicotine, and marijuana use developmentally; (b) investigate the effects of early-onset status and frequency of nicotine and marijuana use on alcohol outcomes, controlling for the effects of alcohol use; and (c) examine gender differences in the developmental trajectories of alcohol outcomes and the effects of nicotine and marijuana use on alcohol outcomes.
METHOD: This study conducted secondary analysis on a longitudinal study that recruited at-risk youth through fathers' drunk-driving records and door-to-door canvassing in the midwestern United States. The sample included 160 female-male sibling pairs who were assessed on substance use and Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, diagnosis from early childhood to young adulthood.
RESULTS: Although males were at higher risk for being early-onset alcohol users, females tended to be at higher risk for initiating marijuana use at younger ages. When early onset and amount of alcohol use were controlled for, early onset of nicotine and marijuana use did not contribute to alcohol outcomes, but frequencies of nicotine and marijuana use did. We also found the associations of quantity/frequency of alcohol and marijuana use with drinking problems to be stronger among females than among males.
CONCLUSIONS: Higher frequencies of nicotine and marijuana use may contribute to worse alcohol outcomes above and beyond the effect of alcohol use. Females tend to be at higher risk than males for initiating marijuana use and meeting an alcohol use disorder diagnosis at younger ages as well as being more vulnerable to a negative impact of alcohol and marijuana use.