Well-Being in the Mid-Twenties: The Influence of Universal Preventive Interventions Mediated Through Substance Use and Depression During Early Emerging Adulthood

Introduction: Earlier research has demonstrated family and school preventive intervention effects on age 21-22 illicit use of substances and depression symptoms. However, there is a gap in the research regarding effects on later well-being and satisfaction variables. We predicted that the interventions’ effects on illicit use of substances and depression symptoms at age 21-22 would influence life course variables at age 25, including (1) well-being, (2) job satisfaction, (3) satisfaction with income, and (4) negative life events. We tested a path model that examined those mediated influences.

Method: Students enrolled in 36 rural Iowa schools participated in a randomized controlled trial consisting of three conditions: (1) school-based (LifeSkills Training, LST) plus the family-focused (Strengthening Families Program: For Parents and Youth 10-14) interventions; (2) LST-only and; (3) a minimal contact control group. Students completed in-home assessments at baseline (N=670) and were followed through age 25 (N=568). Mediating measures were symptoms of depression and illicit use of substances (marijuana, other illicit substances, prescription drug misuse) at age 21-22. Control variables, assessed at baseline, were adolescent substance initiation (alcohol, drunkenness, tobacco, marijuana, inhalants), parents’ and adolescents’ depression symptoms, and sex. Outcome measures were the well-being and satisfaction variables listed above, at age 25. The intervention groups were combined and compared with the control group because age 21-22 mediators did not significantly differ between the individual intervention groups. Path analyses with latent variables were conducted with MPlus 6.1, using the MLR estimator, to assess indirect intervention effects; FIML was used to address missing data.

Results: Path model analyses showed significant indirect effects of the combined intervention groups on all latent variables.

Conclusions:  Participation in preventive interventions during early adolescence can reduce illicit use of substances and depression symptoms during young adulthood, leading to improved general well-being, satisfaction with job and income, as well as avoidance of negative life events. Results support the broad-spectrum, long-term effects of appropriately-timed universal preventive interventions.