Age and alcohol, marijuana and hard drug use

Developmental theories of adolescent alcohol, marijuana and hard drug use have emphasized the factor of age as an explanatory variable. However, studies have not attempted to examine the manner in which age interacts with other explanatory variables to predict usage. This article examines the interactive nature of age in predicting alcohol, marijuana and drug use based on a sample of 435 students from schools in a north-central county of Illinois. The results indicated statistically significant interaction terms for age with peer and social control factors for each type of usage. These findings suggest that many factors commonly associated with adolescent usage may be conditioned by age. The article also recommends that additional research examine the interactive nature of age, as well as other factors, when testing theories of alcohol, marijuana and drug use among adolescents.