Broader Commitment Criteria Lowers Homicide Rates – Study Summary

Homicide rates correlated with civil commitment standards and availability of hospital beds for mentally ill.

(Note: 1,000 or more homicides in the US are committed by people with untreated severe mental illness.. The following study sheds light on that. -ed)

A new 50 state study shows that homicide rates are correlated with civil commitment standards, the availability of inpatient psychiatric beds, and high-quality mental health services. This seems to confirm what advocates for improved commitment standards, increased inpatient psychiatric beds, and better mental illness treatment have have been suggesting anecdotally.

The study, “Civil commitment law, mental health services, and US homicide rates” was published in November 10, 2011 issue of Social Psychiatry and Psychiatric Epidemiology and conducted by Steven P. Segal of the School of Social Welfare at Berkeley. Read complete study.

The author graded by state the restrictiveness of inpatient and outpatient commitment laws using Bazelon and Treatment Advocacy Center data. He then correlated this with the 2004 homicide rates by state using a multivariate statistical model that also included quality of state mental health system (using NAMI’s “Grading the States”), availability of inpatient beds, as well as many other variables indicative of population structure, poverty, social disorganization, firearms restriction, etc. Among the findings:

1. Social (e.g., poverty) and demographic (e.g., more young males) factors had, as expected, the strongest correlation with homicide rates.
2. Controlling for all the other variables, broader (i.e., less restrictive) involuntary civil commitment statutes correlated with lower homicide rates (p<0.01). So did better access to psychiatric inpatient beds (p<0.03) and better state mental health systems (p<0.04) but not as strongly.
3. These three “mental health system characteristics accounted for 17% of the homicide rate variance.”
4. The social and demographic factors accounted for 25% of the variance

.Broader involuntary civil commitment 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-geo- graphic-and-political indicators show the strongest associ- ation 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.


“The association of violent behavior with severe and especially untreated mental illness, most notably with schizophrenia, has been established.”