Understanding the Interplay of Individual and Social-Developmental Factors in the Progression of Substance Use and Mental Health from Childhood to Adulthood

Introduction. Using a life course developmental framework, this study examines the interplay between individual and social-developmental factors in the development of positive functioning, substance use problems, and mental health problems. This interplay is nested within positive and negative developmental cascades that span childhood, adolescence, the transition to adulthood, and adulthood. The present study examined two research questions: 1) Are there general and specific cascades of positive social environments, mental health and substance use? 2) Is their interplay between individual and their social environment or across domains of substance use and mental health?

Method. This study used longitudinal data from the Seattle Social Development Project, a gender-balanced, ethnically diverse community sample of 808 participants interviewed 12 times from ages 10 to 33.  The study was guided by the Social Development Model, and assessed family, peer, school, neighborhood and work domains.  The study employed MPlus (7.2) to examine path models estimating individual and environmental factors in childhood (ages 10-11), early adolescence (13-14) adolescence (15-18), emerging adulthood (21), early adulthood (24-27), and adulthood (30-33).

Results.  Results supported a model with three clear developmental cascades and interplay between cascades. Positive family social environments set a template for future partner social environment interaction and had positive influences on proximal individual functioning, both in the next developmental period and long-term. Family history of depression adversely affected mental health functioning throughout adulthood. Family substance use began a cascade of substance-specific social environments across development, which was the pathway through which increasing severity of substance use problems flowed. The model also indicated that adolescent, but not adult, individual functioning influenced selection into positive social environments, and significant cross-domain effects were found in which substance using social environments affected subsequent mental health.

Conclusions. Early environments can influence positive adult functioning as well as substance abuse and mental health problems in adulthood.  Family positive environments, history of depression, and drug specific environments have far reaching effects that cascade across development. Our findings support the importance of intervening in these early social environments in shaping these developmental cascades, however, our results also point to the importance of continued intervention in adolescence and adulthood.