Can adolescent depressive symptoms act as a target for reducing intergenerational smoking transmission?

BackgroundParental smoking increases offspring smoking risk. Young people with mental health difficulties are more likely to have parents who smoke and start smoking themselves. Improving mental health in youth could help disrupt intergenerational cycles of nicotine use, but the extent to which depressive symptoms mediate the link between parental and offspring smoking remains unclear. MethodsWe used data on 6,729 participants of the Avon Longitudinal Study of Parents and Children (ALSPAC) with mother-reported data on parental smoking. Counterfactual-based mediation analysis was used to estimate both total and direct effects of parental smoking at offspring age 12 on offspring smoking at age 16 and estimate the indirect effect via offspring depressive symptoms at age 14. We also accounted for early offspring substance use (cigarettes, alcohol, or cannabis) at age 13. Multivariable logistic regression was used to examine pairwise associations between these variables. ResultsMediation analysis showed a total effect of parental smoking on offspring smoking (odds ratio [OR] = 1.44, 95% CI = 1.20-1.72). There was no indirect effect via depressive symptoms (OR = 1.00, 95% CI = 0.99-1.01) when adjusted for confounding. Regression analyses showed parental smoking was associated with early offspring substance use and later offspring smoking but not offspring depression. Early offspring substance use was associated with both offspring depression and later smoking. Higher depressive symptoms were associated with later smoking. ConclusionsParental smoking in early adolescence increases the odds of offspring smoking in later adolescence, but this does not appear to act through offspring depression.