Prospective longitudinal associations between household smoke exposure in early childhood and antisocial behavior at age 12.

Young children exert little control over household tobacco smoke exposure, which is considered a developmental neurotoxicant. Using the Quebec Longitudinal Study birth cohort, we examine prospective associations between early childhood smoke exposure and later antisocial behavior. Parents of 1035 children reported on the presence of household smokers at seven follow-ups from ages 1.5 to 7.5. At age 12, children self-reported on five aspects of early antisocial dispositions. After adjusting for confounders, every standard deviation increase in household smoke exposure was prospectively associated with a 19% standard deviation unit increase in conduct problems (ß=0.07; 95% confidence interval [CI] from 0.04 to 0.09), a 11% standard deviation unit increase in proactive aggression (ß=0.04; 95% CI from 0.01 to 0.07), a 13% standard deviation unit increase in reactive aggression (ß=0.07; 95% CI from 0.03 to 0.12), a 14% standard deviation unit increase in school indiscipline (ß=0.13; 95% CI from 0.05 to 0.20), and a 10% standard deviation unit increase in dropout risk (ß=0.07; 95% CI from 0.01 to 0.12). These long-term findings warrant fostering parental awareness of developmental risks by policy-makers/health practitioners. School curricula can equally integrate these ideas into their curriculum.

Predicting academic and cognitive outcomes from weight status trajectories during childhood.

OBJECTIVE: To identify childhood body mass index (BMI) trajectories and to describe their association with subsequent academic and cognitive outcomes. STUDY DESIGN: Prospective cohort: Height and weight measured annually from 4 to 7 years. A mixture of regressions approach grouped children into BMI trajectories (n=1959 children; n=5754 BMI measures). Academic outcomes included teacher-rated progress and achievement. Cognitive outcomes measured by Kaufman's Assessment Battery for Children. Academic and cognitive outcomes were regressed according to BMI trajectories, controlling for family and individual covariates. Subjects drawn from Quebec Longitudinal Study of Child Development (Canada), a 1998 birth cohort (n=2120). RESULTS: Four clusters of BMI trajectories emerged: two healthy weight groups, one overweight group and one low weight group. Relative to healthy weight, belonging to the overweight or low weight clusters was negatively associated with cognitive and academic outcomes. With the exception of the low weight cluster, this relationship was insignificant in the adjusted model. CONCLUSIONS: Results suggest that during childhood being overweight does not increase risk for poor educational outcomes. Instead, being underweight may the increase risk for poorer cognitive outcomes. Further group-based trajectory modeling (GBTM) for BMI development over time is needed to confirm results.

Predictors and consequences of simultaneous alcohol and cannabis use in adolescents.

BACKGROUND/AIMS: The simultaneous use of alcohol and cannabis is common among adolescents, but has been little studied. In this study, we examine predictors and consequences of this behavior in a population-based sample of high school students. METHOD: Self-reports were obtained from students in Quebec (Canada) followed throughout high school (N=6589). Logistic regressions were used to test the association between individual, family, and peer-related predictors in grades 7-8 and simultaneous alcohol and cannabis use in grade 10, as well as between simultaneous alcohol and cannabis use in grade 10 and experiencing 3 or more substance-related problems of various types (legal, physical, etc.) in grade 11. RESULTS: Most predictors in grades 7-8 were associated with simultaneous alcohol and cannabis use in grade 10. Only variables reflecting early-onset substance use involvement - alcohol intoxication, cannabis use, and drug use by close friend(s) - remained predictive in a multivariate model. Simultaneous alcohol and cannabis use was associated with increased substance-related problems in grade 11, above and beyond baseline problems and the concurrent use of the two substances in separate episodes in grade 10. CONCLUSIONS: Simultaneous alcohol and cannabis use 1) is anticipated by multiple psychosocial risk factors which come together with individual and peer substance use in early high school and 2) is independently predictive of subsequent substance-related problems. Providing adolescents with adequate information regarding the potential harm of simultaneous use may be a useful prevention strategy.

Preventing disruptive boys from becoming heavy substance users during adolescence: a longitudinal study of familial and peer-related protective factors.

Childhood disruptiveness is one of the most important antecedents of heavy substance use in adolescence, especially among boys. The first aim of the present study is to verify whether parental monitoring and friend conventionality protect disruptive boys from engaging in heavy substance-use in adolescence. The second purpose is to examine whether these protective effects are strengthened by attachment to parents or friends respectively. Finally, the third objective is to verify whether the expected protective effect of parental monitoring could be mediated through exposure to conventional friends. A sample of 1037 boys from low socioeconomic neighbourhoods was followed from childhood (age 6) to adolescence (age 15). Parent, teacher, and self-reported measures were used to measure disruptiveness, parental monitoring, family attachment, friend conventionality, and attachment to friends. Results suggest that parental monitoring and friends' conventionality mitigated the relationship between childhood disruptiveness and adolescence heavy substance use. Exposure to conventional friends further mediated the protective effect of parent monitoring. The postulated enhancement of attachment quality on the protective effect of parents or peer behaviors was not confirmed, but low attachment was related to heavier substance use in highly monitored disruptive boys. Parental monitoring, family attachment, and peer conventionality are factors amenable to intervention, and thus represent promising targets for future prevention strategies aimed at-risk boys. Our results underscore the importance of simultaneously addressing the behavioral and the affective dimensions in interventions with parents.