1 Department of Mathematics and Statistics, Concordia University, Montreal, QC, Canada.
2 PERFORM Centre, Concordia University, Montreal, QC, Canada.
3 Department of Psychology, Concordia University, Montreal, QC, Canada.
4 Centre for Research in Human Development (CRDH), Canada.
5 School of Psychology, University of Ottawa, Canada.

Both low socioeconomic status (SES) and behavioural problems in childhood are associated with cardiovascular disease (CVD) in adulthood, but their combined effects on CVD are unknown. Study objectives were to investigate the effect of neighbourhood level SES and behavioural problems during childhood on the development of CVD risk factors and events during adulthood. Participants were from a longitudinal cohort (n = 3792, baseline: 6-13 years of age) of Montreal children, followed from 1976 to 2010. SES was a composite measure of neighbourhood income, employment, education, and single-parent households separately assessed from census micro data sets in 1976, 2001, and 2006. Behavioural problems were assessed based on sex-specific peer assessments. CVD events were from medical records. Sex-stratified multivariable Cox regression models adjusted for age, frequency of medical visits, and parental history of CVD. Males from disadvantaged neighbourhoods during childhood were 2.06 (95% CI: 1.09-3.90, p = 0.03) and 2.51 (95% CI: 1.49-4.22, p = 0.0005) times more likely to develop a CVD risk factor or an event, respectively, than males not from disadvantaged neighbourhoods. Aggressive males were also 50% more likely to develop a CVD risk factor or event. Females from disadvantaged neighbourhoods during childhood were 1.85 (95% CI: 1.33-2.59, p = 0.0003) times more likely to develop a CVD risk factor. Future studies should aim to disentangle the interpersonal from the socioeconomic effects on CVD incidence.