Schizophrenia and violence: the brain on high alert

By Béatrice St-Cyr-Leroux Jul 6th, 2026

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In 5 seconds Some parts of the brains of violent schizophrenics are more active when they think they'll be punished for their behaviour, an UdeM neuroimaging study finds.

For Stéphane Potvin, it is essential to avoid conflating psychosis with violence.
Photo : Getty

For years now, Stéphane Potvin has been interested in the brain signatures associated with violent behaviour by schizophrenics.

A professor in the Department of Psychiatry and Addiction at Université de Montréal, he doesn't think violence is simply a consequence of what happens in the brain.

He wants to understand the body's biological mechanisms that could eventually lead to new therapeutic tools to prevent violent behaviour.

As a researcher at the Institut universitaire en santé mentale de Montréal and holder of the Eli Lilly Research Chair in Schizophrenia, Potvin points out that the vast majority of people with psychotic disorders do not commit violent acts.

In fact, they are more likely to be victims of violence, not perpetrators.

People with schizophrenia or schizoaffective disorder who have a history of serious physical violence—resulting in significant injury to others, sometimes involving weapons, and often leading to hospitalization —are a small subpopulation.

This group often has other risk factors for violence, such as childhood antisocial behaviour or substance abuse.

It is important, therefore, not to make sweeping generalizations linking psychosis and violence, Potvin believes. “The vast majority of violent acts in society are not committed by people with psychotic disorders,” he says.

Rewards and punishments

In a recent neuroimaging study, Potvin and Alexandra Fortier, an UdeM doctoral student in psychiatry, examined how the brains of people with schizophrenia respond to rewards and punishments.

The scientists observed the brain activity of subjects, monitored by an MRI scanner, as they performed a task involving small rewards and fictitious financial losses.

A series of symbols were displayed on a screen in front of them: a green triangle for a potential financial reward if they completed a timed task, a red triangle for a potential loss if they made an error, and a yellow triangle for a neutral condition.

Potvin and Fortier, the study’s first author, compared the brain responses of people with schizophrenia who had a history of severe physical violence with those who had no history of violence.

Stéphane Potvin, professor in the Department of Psychiatry and Addiction Medicine at Université de Montréal
Photo : Stéphane Potvin

Alexandra Fortier, UdeM doctoral student in psychiatry
Photo : Alexandra Fortier

Stronger response to anticipation

No differences were found between the two groups’ responses to receiving a reward or even an actual punishment.

However, there was a difference when anticipating punishment. In participants with a history of violence, some brain regions became more active when they believed punishment might be coming.

“The regions involved include the dorsal anterior cingulate cortex and the supplementary motor area, two areas associated with attention to stimuli and preparation for action,” Potvin explained.

“There was also increased activity in the lingual gyrus, a region linked to visual attention. We see a state of hypervigilance towards threats or negative emotions, which we have also observed in previous studies.”

For now, the research team is cautious about the potential clinical implications of these results. One neuroimaging study is not enough, Potvin said; the results must be replicated multiple times before solid conclusions can be drawn.

New therapeutic approaches

If future studies confirm certain brain signatures, this could open the door to new therapeutic approaches to anger management, the researchers believe.

One possibility: neuromodulation techniques, such as transcranial magnetic stimulation, which modifies activity in certain brain regions without surgery. It could eventually be used to target circuits involved in hyperreactivity.

“There have been more neuroimaging studies on violent or antisocial behaviours in non-psychotic individuals, and certain correlations are beginning to emerge,” Potvin said.

Over the longer term, research groups around the world have plans to explore the potential of neuroimaging to improve tools for predicting the risk of violent recidivism. This is a complex endeavour—scientifically, financially and clinically.

In the meantime, Potvin believes this type of research can shed light on the mechanisms at work in a specific minority and help avoid unwarranted generalizations.

“The media focus more on the rare cases of violence committed by people living with a psychotic disorder than on the violence these people experience themselves,” Potvin said.

“In the case of people with schizophrenia, fear of violence is often one of the main drivers of stigmatization.”

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