Background: This epidemiological investigation was designed to examine the relationships between each of the major mental disorders and criminal violence. Specifically, we assessed whether a significant relationship exists between violence and hospitalization for a major mental disorder, and whether this relationship differs for schizophrenia, affective psychoses, and organic brain syndromes.
Methods: Subjects were drawn from a birth cohort of all individuals born between January 1, 1944, and December 31, 1947, in Denmark (N = 358 180). Because of the existence of accurate and complete national registers, data were available on all arrests for violence and all hospitalizations for mental illness that occurred for individuals in this cohort through the age of 44 years.
Results: There was a significant positive relationship between the major mental disorders that led to hospitalization and criminal violence (odds ratios 2.0-8.8 for men and 3.9-23.2 for women). Persons hospitalized for a major mental disorder were responsible for a disproportionate percentage of violence committed by the members of the birth cohort. Men with organic psychoses and both men and women with schizophrenia were significantly more likely to be arrested for criminal violence than were persons who had never been hospitalized, even when controlling for demographic factors, substance abuse, and personality disorders.
Conclusions: Individuals hospitalized for schizophrenia and men hospitalized with organic psychosis have higher rates of arrests for violence than those never hospitalized. This relationship cannot be fully explained by demographic factors or comorbid substance abuse.