Effects of Preventive Intervention in Childhood on Adult Functioning and Health through the 30s: Long-Term Follow-up of the Seattle Social Development Project

Introduction:Public schools, available to all children in the United States beginning at age 5 or 6 years, are a potentially powerful setting for preventive intervention. This study examines the effects of a 3-component preventive intervention provided in public schools during the elementary grades on outcomes through age 39, 27 years after the intervention ended. The intervention aimed to improve the skills of teachers, parents, and children themselves to increase positive functioning in school and decrease problems related to delinquency, substance use, mental health, and risky sexual behavior. It was hypothesized that, to the extent the intervention increased positive functioning and reduced problem behaviors, youth would be put on a more positive developmental trajectory in multiple domains of life with long lasting effects into adulthood. Previous studies have shown effects across adolescence and into the 20s, including better educational and economic attainment, mental health, and sexual health by age 27. The present study extends analyses through the 30s to better understand how and for how long effects persist.

Methods:Data are from the Seattle Social Development Project (SSDP), a diverse Seattle-based longitudinal cohort of 808 that was interviewed 15 times from age 10 to age 39, corresponding to years 1985 to 2014. The SSDP sample is gender balanced, multiethnic, and economically diverse. Surveys in adulthood assessed marriage/romantic relationships and family life, education and employment status, income and assets, community and civic engagement, criminal behavior, health-promoting behavior, substance use and mental health disorder symptoms (corresponding to the DSM-IV), physical health problems, and risky sexual behavior. Objective assessments of body mass index and blood pressure were also included.

Results: Results indicate a consistent pattern of better outcomes through the 30s among those who received the full intervention program in the elementary grades. Long-term effects are particularly notable for improved mental health, including significantly less adult occurrence of depressive and anxiety disorders through age 39. Findings for possible mechanisms of indirect effects as well as moderation of effects by ethnicity indicate how and for whom the grade school interventions had an enduring impact.

Conclusions: Results support the proposition that a universal intervention for urban elementary school children, focused on classroom management and instruction, children’s social competence, and parenting practices, can have enduring effects into adulthood. The consistent pattern of improved outcomes in some domains is evident up to 27 years post-intervention.