Housing mobility and adolescent mental health: The role of substance use, social networks, and family mental health in the moving to opportunity study

•It is unclear why a large housing voucher experiment affected youth mental health.•We tested mediators to understand the effects of this policy relevant exposure.•We apply innovative, flexible mediation methods and bias sensitivity analyses.•Substance use was a robust mediator of housing mobility on boys' behavior problems.•Mediators of opposite-gender housing mobility effects may be gender-specific.

The Moving to Opportunity (MTO) experiment was a housing mobility program begun in the mid-nineties that relocated volunteer low income families from public housing to rental units in higher opportunity neighborhoods in 5 US cities, using the Section 8 affordable housing voucher program. Compared to the control group who stayed behind in public housing, the MTO voucher group exhibited a harmful main effect for boys' mental health, and a beneficial main effect for girls' mental health. But no studies have examined how this social experiment caused these puzzling, opposite gender effects. The present study tests potential mediating mechanisms of the MTO voucher experiment on adolescent mental health (n=2829, aged 12-19 in 2001-2002). Using Inverse Odds Ratio Weighting causal mediation, we tested whether adolescent substance use comorbidity, social networks, or family mental health acted as potential mediators. Our results document that comorbid substance use (e.g. past 30 day alcohol use, cigarette use, and number of substances used) significantly partially mediated the effect of MTO on boys' behavior problems, resulting in -13% to -18% percent change in the total effect. The social connectedness domain was a marginally significant mediator for boys' psychological distress. Yet no tested variables mediated MTO's beneficial effects on girls' psychological distress. Confounding sensitivity analyses suggest that the indirect effect of substance use for mediating boys' behavior problems was robust, but social connectedness for mediating boys' psychological distress was not robust. Understanding how housing mobility policies achieve their effects may inform etiology of neighborhoods as upstream causes of health, and inform enhancement of future affordable housing programs.