Baseline Insurance Status and Risk of Common Mental Disorders: A Propensity-Based Analysis of a Longitudinal U.S. Sample.

OBJECTIVE:Because of pervasive poor general medical and mental health status among patients receiving Medicaid, there has been substantial debate about whether Medicaid, as currently financed and delivered, is better than no insurance. The study aimed to address whether insurance status is associated with the subsequent incidence and persistence of common mental disorders. METHODS:Data came from a nationally representative U.S. population-based longitudinal survey that assessed mental disorders at two time points three years apart. Propensity score methods were used to adjust for potential confounding and to assess the association between three mutually exclusive insurance status groups (no insurance, private insurance only, and Medicaid only) and the subsequent incidence and persistence of mood, anxiety, and substance use disorders for persons ages 18-65 (N=26,410). RESULTS:Compared with private insurance, lack of insurance was associated with higher odds of both the incidence and persistence of substance use disorders and with higher odds of persistence of any mood or anxiety disorder. Compared with having private insurance, having Medicaid insurance was associated with increased odds of persistent mood and anxiety disorders during follow-up. Overall, findings did not significantly differ between the uninsured and Medicaid groups. CONCLUSIONS:The findings do not support prior reports that U.S. adults with Medicaid have worse mental health outcomes than uninsured adults. Lacking insurance may put individuals at higher risk of developing substance use disorders, and uninsured individuals with preexisting mental conditions were more likely to have mood, anxiety, and substance use problems that persist over time.