Study Provides More Insight Into Association Between Schizophrenia, Violence

The connection between violent behavior and schizophrenia is complex and not fully understood. A study published April 24 in AJP in Advance has now provided a detailed, prospective assessment of characteristics that contribute to violent behavior among people getting treatment for schizophrenia.

While the overall rates of violence in the patients with schizophrenia were low, the results reinforce that a history of violent behavior is the strongest predictor of future violence. The study also revealed that recent victimization is a strong predictor of some types of violence.

The findings come from an analysis of the 1,435 participants in the Clinical Antipsychotic Trials of Intervention Effectiveness (CATIE) study. This nationwide study was conducted nearly two decades ago to compare the effectiveness of various new (at the time), second-generation antipsychotic medications. Researchers assessed the participants’ violent behavior at the start of the study and every six months for its 18-month duration.

Based on the participants’ baseline responses, they were placed into one of three categories: no history of violent behavior, a history of violence but none that led to injury (noninjurious violence), or a history of injurious violence. Other potential predictors of violent behavior that were assessed included severity of schizophrenia symptoms, history of childhood abuse, alcohol and substance use, recent victimization, hospitalizations, arrests, and socioeconomic factors such as income and food or housing instability.

During the study period, 86% of participants reported no violence of any kind, 8.3% reported engaging in noninjurious violence, and 5.4% reported engaging in injurious violence. These findings point to the low prevalence of violence in this population, noted lead author Alec Buchanan, Ph.D., M.D, a professor of psychiatry at Yale University School of Medicine.

Among all participants, those with a history of violent behavior leading to injury were four times as likely to engage in injurious violence during the 18-month study period. The second strongest predictor was being the victim of a recent violent attack, which led to a 3.5-times increased risk of future injurious violence. Participants with a history of noninjurious violence were about 2.7 times as likely to commit injurious violence.

Only three other variables were associated with future violence by patients with schizophrenia: a history of childhood sexual abuse, severe/persistent drug use, and poor adherence to medication.

“What’s interesting is that when we took away the people with a history of injuring others from the analysis, victimization was no longer correlated with future violence,” Buchanan told Psychiatric News. “Being a victim of violence is only a risk factor for future violence if you have been violent too.”

Buchanan said this finding supports the idea that people with schizophrenia often encounter interactional violence; that is, they will hurt and be hurt within a short time frame. These repeated violent encounters typically involve people in the patients’ circle, such as family or friends, Buchanan said.

Buchanan hopes this study will help psychiatrists better understand the risks of violence and possible steps they can take to help protect their patients from violence. In particular, the association of substance use severity and medication nonadherence with risk for future violence shows how maintaining a good therapeutic alliance with patients and their family members can mitigate the rare but real risk that a patient will injure someone.

The authors reported no funding information in the article. ■