Maternal predictors of comorbid trajectories of cigarette smoking and marijuana use from early adolescence to adulthood.

This is the first study to examine maternal predictors of comorbid trajectories of cigarette smoking and marijuana use from adolescence to adulthood. Participants (N=806) are part of an on-going longitudinal psychosocial study of mothers and their children. Mothers were administered structured interviews when participants were adolescents, and participants were interviewed at six time waves, from adolescence to adulthood. Mothers and participants independently reported on their relationships when participants were X¯ age 14.1 years. At each time wave, participants answered questions about their cigarette and marijuana use from the previous wave to the present. Latent growth mixture modeling determined the participants' membership in trajectory groups of comorbid smoking and marijuana use, from X¯ ages 14.1 to 36.6 years. Multivariate logistic regression was used to assess the association of maternal factors (when participants were adolescents) with participants' comorbid trajectory group membership. Findings showed that most maternal risk (e.g., mother-child conflict, maternal smoking) and protective (e.g., maternal affection) factors predicted participants' membership in trajectory groups of greater and lesser comorbid substance use, respectively. Clinical implications include the importance of addressing the mother-child relationship in prevention and treatment programs for comorbid cigarette smoking and marijuana use.