Running head : Lifecourse socioeconomic position and substance use 1 Lifecourse socioeconomic position and tobacco and cannabis use

250 in se rm -0 07 08 18 9, v er si on 1 14 J un 2 01 2 Author manuscript, published in "European Journal of Public Health 2012;:epub ahead of print" DOI : 10.1093/eurpub/cks065 Running head: Lifecourse socioeconomic position and substance use 2 Background: Social inequalities in substance use have been well-documented; however the impact of changes in socioeconomic position from childhood to adulthood is unclear. We examined the relationship between intergenerational trajectories of social position and tobacco and cannabis use among young adults. Methods: Data come from 1,103 participants (mean age 28.9) of the TEMPO study and their parents, participants of the GAZEL study, France. Multinomial regression analyses were used to examine associations between lifecourse socioeconomic position (SEP) assessed using parents’ reports of family income (1989 and 2002) and participants’ educational attainment, occupational grade and job stability in 2009, with self-reported tobacco and cannabis use in 2009. Results: Compared to participants with stable intermediate/high SEP, those with stable low SEP and those with declining SEP were more likely to use tobacco (age and sex-adjusted ORs = 2.03 and 2.26). Participants who experienced declining SEP were also disproportionately likely to use and abuse cannabis (adjusted ORs = 2.22 and 2.73). Associations remained significant after adjusting for family (parental smoking, alcohol use, ill health, unemployment, depression and divorce) and individual (early tobacco and cannabis use, academic difficulties, juvenile internalising and externalizing problems) risk factors. Conclusions: Cross-sectional studies indicate social inequalities in substance use. Our longitudinal findings suggest that individuals who experienced declining SEP from childhood to adulthood may be twice as likely to use tobacco and cannabis compared to individuals with a stable/high trajectory. Interventions targeting substance abuse should take into account lifecourse determinants including the interplay between individuals’ socioeconomic origins and later attainment. Abbreviations: SEP: Socioeconomic position in se rm -0 07 08 18 9, v er si on 1 14 J un 2 01 2 Running head: Lifecourse socioeconomic position and substance use 3