Premorbid risk factors for violence in adult mental illness.

The role of premorbid factors in the violence associated with adult mental illness has received little attention. We previously found that the premorbid onset of substance abuse in early adolescence or childhood was a more powerful predictor of violence in adult patients with chronic mental illness than comorbid substance abuse. In the present study, we retrospectively assessed patients with chronic mental illness for a history of childhood conduct disorder. Consecutive referrals to a community treatment team were evaluated with a standardized protocol that included questions about violent behavior. Patients who met DSM-IV criteria for a primary diagnosis of major axis I disorder (N = 64) were assessed for behavior prior to age 15 with a checklist for DSM-IV criteria of conduct disorder using self-report data, supplemented by collateral information from charts and relatives when possible. About half of the sample had a history of committing violent acts in the community, and 26% met criteria for childhood conduct disorder. The odds of violence in adulthood was 10-fold higher for subjects with a history of childhood conduct disorder. Not surprisingly, there was considerable overlap between conduct disorder and early-onset substance abuse. About half of the patients with a history of substance abuse prior to age 15 also had a history of conduct disorder. However, these two premorbid conditions appear to be at least partially independent in predicting adult violence in this population.