Sex differences in the association between parental monitoring and substance use initiation among adolescents

Introduction: Parental involvement and supervision (i.e., "parental monitoring;" PM) is generally inversely associated with substance use among youth; yet, specific features of this association remain unclear. This study examined PM as a prospective predictor of substance use initiation across adolescence and whether associations generalize across a range of substances and by sex. Methods: Participants were enrolled in a longitudinal cohort study of high school students from Southern California. We assessed, among never-users at baseline (2014; participants were in 10th grade), the role of PM in 8 substance use initiation outcomes (initiation of 7 individual substances or categories of substances: alcohol, cigarettes, electronic (e-) cigarettes, cigars, marijuana, stimulants, or opioids, as well as the total number of substances initiated) at follow-up (2017; 12th grade), controlling for sociodemographic characteristics. Multiplicative interactions assessed differences by sex. Results: In adjusted main effects models, PM was associated with lower odds of initiation of all substances (OR range: 0.60 for cigarettes to 0.82 for alcohol) and male sex was associated with increased odds of initiating use of cigarettes (OR = 1.33, 95% CI = 1.02, 1.73) and cigars (OR = 1.82, 95% CI = 1.32, 2.52) over follow-up. There were also significant PM x sex interactions for cigarettes (p = 0.038), e-cigarettes (p = 0.042), and marijuana (p = 0.044), whereby lower PM was associated with greater odds of initiation among females, compared to males. Conclusions: PM is associated with reduced odds of initiating use of multiple substances among adolescents, particularly for females. Future research of the mechanisms underlying these associations can point towards intervention targets to prevent or delay substance use initiation among youth with low PM.