Return on investment in public mental health and substance use systems: Does it lead to reductions in suicide rates?

Objectives: We examine the extent to which states' mental health spending and substance use treatment capacity reduce suicide rates.

Methods: We analyze state-year time-series-cross-sectional data on the per-capita number of suicides per 100,000 persons for 50 states and D.C. for the years 2001–2009 (N = 459). Main independent variables include (a year-lagged) state Mental Health Agencies' spending on mental health programs (first for total and then separately for inpatient and community settings) and the per-capita number of public hospital beds used for substance use treatment. We control for state spending on mental health and substance use treatment in community-settings, private substance use beds, public and private hospital psychiatric beds, unemployment rates, per-capita income, and proportion of residents on Medicaid and welfare. To minimize bias from unobserved state-level confounders, we control for state and year fixed-effects and time trends specific to each state. Standard errors are adjusted for detected violations of panel heteroskedasticity, contemporaneous correlation and autocorrelation.

Results: Consistent with prior research, we do not find a statistically significant effect of per-capita total state mental health spending on suicide rates. However, a 100-dollar increase in per-capita state spending on mental health treatment in inpatient settings is associated with a reduction of 2.2 suicides per 100,000 persons. A one-bed increase in hospital substance use beds per 1,000 persons is significantly associated with a reduction of 3 suicides per 100,000 persons.

Conclusion: States' investment in the mental health and substance use treatment systems appears to reduce suicide rates.