Criminality in men with major mental disorder with and without comorbid substance abuse.

Violent and criminal behavior in the mentally ill remains an issue of major importance and in this context the role of comorbid substance abuse must be addressed. Data on criminal behavior in 282 men with schizophrenia and 261 men with affective disorder were studied. Samples of patients with and without additional substance abuse were compared. Also, non-abusing patients from both diagnostic groups were compared with matched controls from the general population. Substance abuse was found in half of all men in both groups of major mental disorders, and substance abusers had twice as high a probability of having a criminal record. However, compared with the matched sample from the general population, violent criminality was increased in schizophrenic patients without comorbid substance abuse, and patients with affective disorders without substance abuse had a higher probability of committing crimes against property. Men with major mental disorder have an increased probability of becoming criminal even when there is no comorbid substance abuse.