A public health perspective on violent offenses among persons with mental illness

This study reanalyzed existing data to assess the extent to which persons with mental illness might contribute to criminal violence in the community.

Data were examined from a representative sample of 1,151 remanded offenders who underwent a full structured diagnostic interview that was used to provide one-month prevalence rates of mental illnesses as defined by the Structured Clincal Interview for DSM-III-R. Diagnoses of interest were mood, psychotic, anxiety, psychoactive substance use, adjustment, and miscellaneous axis I disorders and axis II personality disorders. Criminological data describing the number of offenses against persons and property and the number of victimless crimes were abstracted from police arrest reports and warrants. A violent crime was defined as any crime against a person.

The one-month prevalence of major mental and substance use disorders of newly admitted inmates was 61 percent. About 3 percent of violent offenses could be attributed to individuals who had a principal diagnosis of any non-substance use-related disorder. An additional 7 percent of violent offenses could be attributed to individuals who had a primary diagnosis of a substance use disorder.

The results of the study support the hypothesis that people with mental and substance use disorders are not major contributors to police-identified criminal violence. Public perceptions of mentally ill persons as criminally dangerous appear to be greatly exaggerated.