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

Background and Purpose. In social work we recognize that development is complex, contextually determined, and has cascading effects throughout life.  However, research models of development are often simple and developmentally limited.  This study proposes and tests a model of the interplay between individual and social factors in the development of positive functioning, substance abuse and mental health problems. This interplay is seen as producing both positive and negative developmental cascades that span four developmental periods: childhood, adolescence, the transition to adulthood and adulthood.  The purpose of the study is to set a research agenda for the future that better reflects a contextualized understanding of development. 

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.  In adulthood, the Diagnostic Interview Schedule was used to assess substance abuse and mental health symptoms. The present study examined three hypothesized SDM-informed pathways: a positive environment and functioning pathway, a substance use pathway, and a mental health related pathway. Cross-pathway models were also tested. 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: (1) a positive development pathway from positive family functioning in childhood, positive partner environment in the transition to adulthood, leading to better general positive functioning at ages 30-33;  (2) a substance use pathway from family substance using environment in childhood to peer substance use in adolescence, early adult abuse and dependence symptoms and partner substance use in the transition to adulthood, leading to drug abuse and dependence diagnosis at ages 30-33;  and (3) a mental health pathway from family history of depression in childhood, to anxiety and depression symptoms in the transition to adulthood, leading to anxiety and depression diagnosis at ages 30-33.  In addition to these three cascading pathways, some cross-pathway influences were observed, in particular from general positive family functioning in childhood, across to all three developmental cascades. Furthermore, family history of depression was a significant predictor of adult mental health diagnosis over and above intervening influences. All models controlled for gender, ethnicity and socioeconomic status.  Fit indices indicate a well-fitting model (CFI = .975, RMSEA .038).

Implications. 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. This developmental cascade model also supports the idea that it is never too early and never too late to intervene.  Social workers have an opportunity to affect these positive and negative developmental cascades through prevention and intervention.