Seena Fazel, M.D., a professor of forensic psychiatry at the University of Oxford, United Kingdom, and coauthors used nationwide Swedish data for individuals born between 1958 and 1988 to examine a range of triggers for violent crimes in patients with psychotic disorders and individuals without a psychiatric diagnosis. The study sample included 34,903 patients who were diagnosed with schizophrenia spectrum disorders, 29,692 patients with bipolar disorder, and more than 2.7 million people who had never been diagnosed with a psychiatric disorder.
Within each subsample, the authors identified people who had experienced any of the following triggers for violent acts: exposure to violence, parental bereavement, self-harm, traumatic brain injury, unintentional injuries, and substance intoxication. The risk of the individual committing a violent crime in the seven days following exposure to a trigger was then compared with risk in earlier periods when they were not exposed to any trigger. (Violent crime was defined as a conviction for homicide, assault, robbery, threats and violence against an officer, unlawful threats, unlawful coercion, kidnapping, illegal confinement, arson, intimidation, or sexual offenses.)
All three groups showed statistically significant associations between each of the six triggers and the rate of violent crime in the week after exposure compared with earlier control periods. Although the absolute risk of violence was greatest in patients with schizophrenia, the relative risks across the three groups was similar, with the exception of parental bereavement, where the authors found stronger relative risks in the patients with schizophrenia (adjusted odds ratio [aOR], 5.0) than in the controls (aOR, 1.7).
“This study demonstrates that violence risk occurs when there are certain triggers, especially substance intoxication and severe stress. This is true whether or not an individual suffers from a mental disorder,” APA Immediate Past President Renée Binder, M.D., a professor of psychiatry and director of the Psychiatry and Law Program at the University of California, San Francisco School of Medicine, told Psychiatric News.
However, interpreting what the findings say about patients with psychotic disorders is more difficult, due to the fact that the authors of the study looked only at diagnoses, not the effect of treatment on modifying risks, she continued.
“The key point in assessing violence risk is not necessarily the diagnosis. Patients who have been diagnosed with schizophrenia or bipolar disorder and who are in remission and are complying with treatment are not at risk for violence. Thus, it is not the diagnosis per se, but rather the stage of illness (acute versus chronic), the treatment status, and whether or not the person is using substances” that are important when evaluating risk of violence in a psychiatric evaluation, she said.
“Clinically, these findings imply that patients with schizophrenia or bipolar disorder should receive a psychiatric assessment for the risk of violence if they sustain an experience similar to one of the triggers tested in this study,” Jan Volavka, M.D., Ph.D., of the New York University School of Medicine, wrote in a related editorial. “The need for assessment is particularly pressing for young patients who have been targets of violence. To be useful, the assessment should occur as soon as possible after the event; certainly within the first week. Depending on the results, the patient may need supportive psychotherapy, medication adjustment, or hospitalization. In general, the findings raise the need to treat comorbid substance use disorders in individuals with schizophrenia and bipolar disorder.”
For related information, see the APA resource document “Psychiatric Risk Assessment,” of which Binder is a coauthor, and the Psychiatric Services article “Proximal Risk Factors forShort-Term Community Violence Among Adults With Mental Illnesses.”