Can mental health competence reduce the higher risk of smoking initiation among teenagers with parents who smoke?

BACKGROUND: Parental smoking strongly influences adolescent smoking, yet few studies have examined factors that may protect against this. We investigated whether skills-based components of positive mental health ('mental health competence', MHC) modified the association between parental and teenager smoking, in the UK-representative Millennium Cohort Study (approximately 18 000 children, born 2000-02; analytic sample: n = 10 133). METHODS: Cohort members (CMs) reported at 14 years (y) whether they had ever smoked cigarettes. A dichotomized variable indicated whether one/both parents smoked when CMs were 11 y. A four-class latent MHC measure captured learning skills and prosocial behaviours at 11 y: High, High-Moderate, Moderate, Low. We examined effect measure modification (on the additive scale) by comparing risk differences (RDs) for CM smoking according to parental smoking, within each MHC class. We then estimated RDs for CM smoking according to combinations of parental smoking and MHC. Analyses accounted for confounding, sample design, attrition and item missingness. RESULTS: CMs were more likely to smoke cigarettes if their parent(s) smoked (27%) than CMs with no parent(s) who smoked (11%; RD: 16%). When stratified by MHC, RDs were stronger for low MHC (21%; 95% CI 11-31%) than other MHC classes (ranging: 7-11%). Compared to CMs with high MHC and non-smoker parents, those with low MHC and parent(s) who smoked had an RD of 28% (95% CI 20-36%). This was greater than the sum of RDs for those with low MHC and non-smoker parent(s) [7% (2-14%)] plus those with high MHC and whose parent(s) smoked [11% (7-15%)]. There was limited effect measure modification by moderate or High-Moderate MHC. CONCLUSION: Improving MHC to moderate levels may help reduce intergenerational transference of smoking.