The relationship between early age of onset of initial substance use and engaging in multiple health risk behaviors among young adolescents

Background: Previous research based on problem-behavior theory has found th at early age of onset of substance use is associated with engaging in multi ple health risk behaviors among high school students. It is unknown whether these relationships begin during early adolescence. Objective: To examine the relationships between early age of onset of cigar ette, alcohol, marijuana, and cocaine use and engaging in multiple risk beh aviors among middle school students. Methods: A modified version of the Centers for Disease Control and Preventi on You th Risk Behavior Survey was administered to 2227 sixth through eight h grade students attending 53 randomly selected middle schools in North Car olina. A Health Risk Behavior Scale was constructed from 16 behaviors, incl uding indicators of violence and weapon carrying; current substance use; no nuse of helmets when biking, in-line skating or skateboarding; not wearing a seat belt; riding with a driver who had been drinking; and suicide plans. Among this sample of middle school students, the scale had a mean (SD) of 4.1 (2.7) (range=0-15),and had a high internal reliability coefficient (alp ha=0.74). The independent variables included first time use of cigarettes, alcohol, marijuana, and cocaine at age 11 years or earlier; actual age of o nset of each substance; race and ethnicity; family composition; sex; school grade; academic ranking; and older age for school grade. These data were a nalyzed with analysis of variance, Spearman r, and multiple linear regressi on. Results: All the independent variables were found to be associated (P<.005) with the Health Risk Behavior Scale during the bivariate analyses. When ea ch of these significant variables were entered into a multiple regression m odel, having smoked at age 11 years or younger accounted for 21.9% of the v ariation in the Health Risk Behavior Scale. Male sex, early marijuana or co caine use, older age, lower academic rank, white race, and living in a 1-pa rent family explained an additional 19.1% of variation in the model (adjust ed R-2=0.41, P<.001). When the actual ages of onset of the use of substance s were analyzed, in order of magnitude; age of onset of smoking; male sex; age of onset of alcohol and marijuana use; age; lower academic ranking; age of onset of cocaine use; white race; and lower academic rating accounted f or 52.8% (P<.001) of the variation in the Health Risk Behavior Scale. Conclusion: Even when considering sociodemographic factors, early age of on set of cigarette use was the strongest correlate of the number of health ri sk behaviors in which these young adolescents had engaged. Early onset of u se of other substances was also associated with a clustering of health risk behaviors among this sample of middle school students. The findings sugges t that screening for early experimentation with tobacco and other substance use will help identify young adolescents at increased risk for engaging in multiple health risk behaviors.