Antipsychotic use linked to reduced patient violence

By Eleanor McDermid, Senior medwireNews Reporter

Prescribing antipsychotics may reduce psychiatric patients’ propensity to commit violent crime, a study in The Lancet suggests.

Mood stabilisers had a similar effect, but only in patients with bipolar disorder, report lead researcher Seena Fazel (University of Oxford, UK) and colleagues.

In a press release, Fazel said that the study “provides evidence of potentially substantial reductions in risk of violence, and suggests that violence is to a large extent preventable in patients with psychiatric disorders.”

The researchers obtained data from Swedish national registers for 82,647 patients prescribed antipsychotics or mood stabilisers between 2006 and 2009. The overall rate of violent crime in this cohort during this period, including crimes that did not lead to conviction and those that were investigated but no charges were brought, was 6.5% among men and 1.4% among women.

Fazel et al found that rates of violent crime fell by a significant 45% during periods when patients were taking antipsychotics relative to when they were not. There was also a significant 24% reduction associated with use of mood stabilisers.

However, when grouped by diagnosis, the effects of mood stabilisers were only significant for patients with bipolar disorder, who had a 56% reduction in violent crime.

Antipsychotic treatment was associated with a significant 35% reduction in violent crime among patients with schizophrenia, a 48% reduction among those with bipolar disorder and a 57% reduction among patients with other psychotic disorders.

Neither antipsychotics nor mood stabilisers were associated with reductions in violent crime among patients with depression.

In a commentary accompanying the study, Sheilagh Hodgins (University of Montreal, Quebec, Canada) highlights that there was a significant 43% reduction in violent crime for all patients given a psychiatric drug, despite about 60% of patients not having a psychotic diagnosis.

“These results might represent the increased risk of violent behaviour in people with psychotic-like experiences who do not have psychotic disorders”, she suggests, adding that this “warrants further investigation.”

Hodgins also notes that among schizophrenia patients, those who commit violent crimes are not a homogeneous population. In particular, she points out that those with conduct disorder predating schizophrenia onset “represent a distinct phenotype who may respond differently than other patients to antipsychotic drugs.”

Licensed from medwireNews with permission from Springer Healthcare Ltd. ©Springer Healthcare Ltd. All rights reserved. Neither of these parties endorse or recommend any commercial products, services, or equipment.