Civil Commitment Law, Mental Health Services, and US Homicide Rates

Purpose: 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?

Method: 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.

Results: 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.

Conclusions: 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.