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Exposure to violence increases risk for violent crime regardless of psychiatric disorder

Exposure to violence increased risk for violent crime among individuals with and without psychotic disorders, and parental bereavement particularly increased risk for crime among those with schizophrenia.

“Three pilot studies conducted within Swedish correctional and forensic settings on 327 individuals have suggested that certain symptoms and, particularly, alcohol intoxication and high doses of benzodiazepines may trigger violence within 24 hours. However, the generalizability of these findings remains limited owing to their small and highly selected samples. More important, it is not known how such triggers act in individuals with psychosis,” Amir Sariaslan, PhD, of University of Oxford, Warneford Hospital, United Kingdom, and colleagues wrote. “The identification of triggers for violence is potentially clinically important for risk assessment, which is recommended in patients with schizophrenia by systematic reviews but currently relies mostly on historical factors and is moderately accurate at best.”

To determine if a range of triggers for violent acts were associated with risk for violence among individuals with psychotic disorders, researchers evaluated a sample of all individuals born in Sweden between 1958 and 1988 (n = 3,123,724). Analysis included 34,903 individuals with schizophrenia spectrum disorders; 29,692 with bipolar disorder and 2,763,012 unaffected controls. Triggers for violent acts included exposure to violence, parental bereavement, self-harm, traumatic brain injury, unintentional injuries and substance intoxication.

Overall, all of the included triggers were associated with increased risk for violent crime in the week following exposure.

Exposure to violence was associated with the largest 1-week absolute risk for violent crime (70 to 177 crimes per 10,000 persons).

Relative risk did not significantly vary by diagnosis following exposure to unintentional injury (adjusted OR range = 3.5 to 4.8), self-harm (aOR range = 3.9 to 4.2) and substance intoxication (aOR range = 3 to 4).

Risk differences by diagnosis included parental bereavement, with a higher risk among individuals with schizophrenia spectrum disorders (aOR = 5; 95% CI, 3-8.1), compared with controls (aOR = 1.7; 95% CI, 1.3-2.2).

“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. 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,” Jan Volavka, MD, PhD, of New York University School of Medicine, wrote in an accompanying editorial. “In general, the findings raise the need to treat comorbid substance use disorders in individuals with schizophrenia and bipolar disorder.” – by Amanda Oldt

Disclosure: The researchers report no relevant financial disclosures.