Mental illness causes violence without any scientific basis
In the wake of a string of violent tragedies across Quebec, politicians have reached for mental illness as an explanation — and a solution. But the human impulse to impose order on chaos through familiar narratives can carry a cost: experts warn that linking violence to mental illness without scientific grounding does more to deepen fear and stigma than to prevent harm. The deeper questions — about isolation, inequality, and the fraying of social bonds — remain harder to legislate, and easier to avoid.
- Four people are dead and communities are shaken after a cluster of violent incidents in Quebec, including the stabbing of a police officer, the killing of two children in a daycare bus attack, and pedestrians struck by a truck.
- Premier Legault has moved quickly to propose involuntary mental health treatment and urged citizens to report worrying behaviour in those around them, framing the tragedies as a mental health crisis demanding urgent state intervention.
- Law professor Emmanuelle Bernheim pushes back sharply, pointing out that research consistently shows people with mental illness are no more violent than the general population — and are far more often victims of crime than perpetrators.
- Involuntary hospitalizations in Quebec have already risen nearly 30 percent and forced treatment 45 percent since 2015, yet the violence has not stopped — undermining the premise that coercive care is the answer.
- Experts warn that proposed registries and police access to mental health review board data risk branding all conditionally discharged patients as dangerous, entrenching stigma without any scientific justification.
- The argument gaining ground among researchers is that the real drivers — social isolation, inequality, and the collapse of support networks — demand structural solutions that political rhetoric about mental illness conveniently sidesteps.
Montreal has been shaken by a series of violent incidents in recent weeks: a provincial police sergeant stabbed to death, two young children killed when a bus driver drove into a Laval daycare, three pedestrians struck by a pickup truck in Amqui, and a teenager charged in the stabbing deaths of three family members. In the aftermath, Quebec Premier François Legault and other politicians have called for stronger mental health interventions, including the possibility of forcing people into treatment against their will.
But Emmanuelle Bernheim, a law professor at the University of Ottawa and Canada Research Chair in mental health and access to justice, is sounding an alarm. The rush to connect these tragedies to mental illness, she argues, rests on a false foundation — research does not support the idea that people with mental health conditions are more likely to commit violence. If anything, they are more often the victims of crime. The stereotype persists, she suggests, because it offers a way to make sense of senseless acts.
The cases themselves are more complicated than the political rhetoric implies. The bus driver and the truck driver had no documented history of violent crime or mental health treatment. The one case with a clear mental health history — the man who allegedly stabbed Sergeant Maureen Breau — had been found not criminally responsible for past offences multiple times, and a review board had already flagged him as a significant risk in 2022.
Legault's proposed response includes faster treatment for those deemed dangerous and encouraging citizens to report concerning behaviour. Bernheim finds this language troubling. Involuntary hospitalizations in Quebec have already risen nearly 30 percent between 2015 and 2020, and forced treatment has climbed 45 percent — yet the tragedies have continued. The police union's push for access to mental health review board data worries her further, raising the prospect of all conditionally discharged patients being treated as presumptively dangerous.
Bernheim argues the focus needs to shift toward the broader conditions that drive harm: widening inequality, the erosion of social services, and the profound isolation that leaves many people without anyone to turn to. 'How can they get help or support if they need it, if they have nobody, in a context where services are really difficult to get?' she asks. Whether Quebec's leaders will follow that argument — or continue down the path of surveillance and coercion — remains the open question.
Montreal has been shaken by a series of violent incidents over recent weeks, each one prompting urgent questions about mental health and public safety. A provincial police sergeant was stabbed to death on March 27 in a town northeast of the city. A bus driver drove into a daycare in Laval, killing two young children. A man in a pickup truck mowed down three pedestrians on a sidewalk in Amqui. A teenager was charged in the stabbing deaths of three family members. In the aftermath, Quebec Premier François Legault and other politicians have called for stronger mental health interventions, even raising the possibility of forcing people into treatment against their will.
But Emmanuelle Bernheim, a law professor at the University of Ottawa and holder of a Canada Research Chair in mental health and access to justice, is sounding an alarm. The rush to connect these tragedies to mental illness, she argues, rests on a false foundation. Research does not support the idea that people with mental health conditions are more likely to commit violence than anyone else. If anything, they are more often the victims of crime. Yet the stereotype persists, perhaps because it offers a way to make sense of senseless acts.
The incidents themselves tell a more complicated story than the political rhetoric suggests. Pierre Ny St-Amand, the 51-year-old bus driver accused of killing the two children in Laval on February 8, is undergoing psychiatric evaluation. Steeve Gagnon, accused of deliberately driving his truck into pedestrians in Amqui, was arraigned on three counts of first-degree murder. Neither man had a documented history of violent crime, and nothing indicates either was receiving mental health treatment. The case that does involve a clear mental health history is different: Isaac Brouillard Lessard, the man who allegedly stabbed Sergeant Maureen Breau, had been found not criminally responsible for past offences at least five times. A mental health review board determined in March 2022 that he posed a significant risk to public safety but believed the risk could be managed through proper monitoring.
Legault's response has been to promise faster treatment for those deemed dangerous and to suggest that people who refuse treatment may need to be hospitalized against their will. He has urged Quebecers to report concerning behaviour in those around them. But Bernheim considers this language problematic. It deepens distrust of people with mental illnesses and ignores what the data actually shows. Involuntary hospital admissions in Quebec have risen nearly 30 percent between 2015 and 2020. Forced treatment has climbed 45 percent. Yet the tragedies continue. "To say we're going to treat people against their will, we'll hospitalize them against their will and it will be fixed, the current practices show that's not the case at all," she said.
The police union representing officers has announced plans to petition the legislature for better supervision of people released from custody and for police to have access to mental health review board data. Bernheim worries this could lead to all conditionally discharged patients being flagged as potentially violent without cause, or sorted into categories based on criteria that remain unclear. "The rhetoric of the past few days is helping to create associations between mental illness and violence, and between non-criminally responsible people and violence, without any scientific basis," she said.
Bernheim does not claim to have all the answers, but she argues the focus should shift. The factors that drive crime are complex and extend far beyond mental health—a term itself poorly defined and widely misunderstood. Societal conditions matter: widening inequality, the erosion of social services, the isolation that leaves many people without support networks. "We know that a lot of people are really alone; they have nobody," she said. "How can they get help or support if they need it, if they have nobody, in a context where services are really difficult to get?" The question now is whether Quebec's political leaders will listen to that argument or continue down the path of involuntary treatment and surveillance.
Notable Quotes
The rhetoric of the past few days is helping to create associations between mental illness and violence without any scientific basis— Emmanuelle Bernheim, Canada Research Chair in mental health and access to justice
To say we're going to treat people against their will and hospitalize them against their will and it will be fixed—current practices show that's not the case at all— Emmanuelle Bernheim
The Hearth Conversation Another angle on the story
Why does connecting violence to mental illness feel so natural to people, even when the research doesn't support it?
Because it offers a story. A tragedy without explanation is unbearable. If we can say the person was mentally ill, we've created a frame—a reason, a category, something that feels controllable. It's comforting in a way that admitting randomness and complexity is not.
But doesn't that comfort come at a cost?
A significant one. When you tell the public that mental illness causes violence, you're creating a permanent association in people's minds. The next time someone hears about a person with a mental health condition, they think danger. That person becomes someone to fear, to report, to control. It changes how they're treated in every interaction.
The premier is proposing involuntary treatment. Doesn't that seem like a reasonable response to keep people safe?
It sounds reasonable until you look at what's already happening. Quebec has been increasing involuntary admissions and forced treatment for years. The tragedies haven't stopped. So either the approach doesn't work, or we're solving the wrong problem.
What would solving the right problem look like?
Looking at the actual conditions people live in. Isolation. Poverty. The collapse of social services. Those are harder to fix than a policy that says we'll hospitalize dangerous people. But they're what actually matter.
How do you balance public safety with not stigmatizing an entire group?
That's the tension. You can't ignore the incidents. But you also can't use them as justification for treating millions of people as potential threats. You have to be precise about what you know and honest about what you don't.
And what happens if we don't make that distinction?
We create a system where people with mental health conditions become a surveilled, controlled population. Flagged in databases. Sorted into risk categories. Afraid to seek help because seeking help marks you as dangerous. That's not safety. That's a different kind of harm.