Parental Knowledge/Monitoring and Adolescent Substance Use: A Causal Relationship?

Objective: Many studies have shown that parental knowledge/monitoring is correlated with adolescent substance use, but the association may be confounded by the many preexisting differences between families with low versus high monitoring. We attempted to produce more rigorous evidence for a causal relation using a longitudinal design that took advantage of within-family fluctuations in knowledge/monitoring during the COVID-19 pandemic. Method: Youth (N = 8,780, age range = 10.5-15.6 years) at 21 sites across the United States completed up to seven surveys over 12 months. Youth reported on their parents' knowledge/monitoring of their activities and their substance use in the past month. Regressions were fit to within-family changes in youth-perceived knowledge/monitoring and substance use between survey waves. By analyzing within-family changes over time, we controlled for all stable, a priori differences that exist between families with low versus high levels of youth-perceived knowledge/monitoring. Results: Youth initially denying substance use were significantly more likely to start reporting use when they experienced a decrease in the level of perceived knowledge/monitoring (relative risk [RR] = 1.18, p < .001). Youth initially endorsing substance use were significantly more likely to stop reporting use when they experienced an increase in the level of perceived knowledge/monitoring (RR = 1.06; p < .001). Associations were similar or larger when adjusting for several time-varying potential confounders. Conclusion: In a large, sociodemographically diverse sample, within-family changes in youth-perceived parental knowledge/monitoring over time were robustly associated with changes in youths' engagement in substance use. Findings lend support to the hypothesis that parent knowledge/monitoring is causally related to substance involvement in early adolescence.