Civil commitment law, mental health services, and US homicide rates

The study considers whether involuntary civil comment (ICC) statute provisions are associated with homicide rates. Do statutes based solely upon dangerousness criteria versus broader ICC-criteria-i.e. "need for treatment," "protection of health and safety," and family protection-have differential associations related to their goal of reducing the frequency of homicide?

State-level data were obtained from online data bases and key-informant surveys. Ordinary-least-squares and Poisson regression were used to evaluate the association between statute characteristics, mental health system characteristics, and 2004 Homicide Rates after controlling for firearm-control-law restrictiveness and social-economic-demographic-geographic-and-political indicators historically related to homicide rate variation.

Poisson and OLS models, respectively, were significant: likelihood ratio χ(2) = 108.47, df = 10; p < 0.000 and Adj. R (2) = 0.72; df = 10, 25; F = 10.21; p < 0.000. Poisson results indicate that social-economic-demographic-geographic-and-political-indicators had the strongest association with state homicide rates (p < 0.000). Lower rates were associated with: broader ICC-criteria (p ≤ 0.01), fewer inpatient-bed access problems (p ≤ 0.03), and better mental health system ratings (p ≤ 0.04). OLS results indicate that social-economic-demographic-geographic-and-political indicators accounted for 25% of homicide rate variation. Broader ICC-criteria were associated with 1.42 less homicides per 100,000. Less access to psychiatric inpatient-beds and more poorly rated mental health systems were associated with increases in the homicide rates of 1.08 and 0.26 per 100,000, respectively.

While social-economic-demographic-geographic-and-political indicators show the strongest association with homicide rate variation, the results show the importance and potentially preventive utility of broader ICC criteria, increased psychiatric inpatient-bed access, and better performing mental health systems as factors contributing to homicide rate variation.