Parental alcohol-specific rules effectively reduce adolescents' tobacco and cannabis use: A longitudinal study

Aims: The current study aimed to longitudinally examine the direct and indirect effects (via alcohol use) of parental alcohol-specific rule-setting on adolescent tobacco and cannabis use. Based on the gateway hypothesis, we expected parental alcohol-specific rules to affect adolescent tobacco and cannabis use through adolescent alcohol use. Design and participants: A longitudinal design including three waves and 906 Dutch adolescents (M-age = 13.51 years, SD = 0.60) was used to apply zero-inflated Poisson models (ZIP). Measurements: Self-report questionnaires measured adolescents' perceived rules about alcohol at T-1, cigarette use at T-1 and T-3 (frequency of life-time and current smoking), cannabis use at T-1/T-3 (frequency of yearly and monthly use) and frequency of monthly alcohol use at T-1/T-2. Findings: Stricter alcohol-specific rules at T i predicted lower incidence and prevalence rates of cigarette (lifetime: beta = - 0.20, p < .00; current beta = - 0.21, p = .04) and cannabis use (monthly: beta = - 0.43, p = .02; yearly: beta = - 0.28, p = .19) two years later (T-3). This direct effect was no longer significant when alcohol use at T-1 was controlled for. Moreover, a significant indirect effect of alcohol-specific rules at T-1 on tobacco and cannabis use T-3 via monthly alcohol use T-2 was found. Conclusions: The current study demonstrated that strict rules regarding alcohol may not only reduce alcohol but subsequently also other substance use such as tobacco and cannabis. Thus, interventions targeting the prevention of alcohol use, which appears to serve as a gateway, also affects the involvement in other substances.