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Decades of research has found that racialized citizens are diagnosed with the disorder at far higher rates – and the single biggest risk factor is having darker skin than most of their neighbours

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Illustration by Rachel Wada

One of the first patients Kwame McKenzie treated as a psychiatrist in London, England, was a young Black man diagnosed with schizophrenia. Dr. McKenzie, then years away from becoming the director of health equity at Toronto’s Centre for Addiction and Mental Health (CAMH), remembers the father, an African-Caribbean immigrant, trying not to cry while asking questions. Had they done something wrong to make their child so ill? This was their second son now suffering from psychosis, the father explained. How could they stop it from happening to their other children? Dr. McKenzie didn’t have a good answer. He resolved to find one.

That search led him to dig deeper into a curious, and alarming, pattern: In a number of Western countries, including Canada, migrants from Africa and the Caribbean – and their children – are more likely to be diagnosed with schizophrenia than either their native-born white peers or immigrants from other parts of the world. Study after study has pointed to one significant risk factor: skin colour.

Schizophrenia, a disorder characterized by often debilitating hallucinations and delusions, is one of the most severe mental illnesses and among the hardest to treat. It is relatively rare – affecting about one per cent of the population – but its burden on patients, their families and the health care system is huge, especially since the illness most often emerges in the late teens and early 20s. People with schizophrenia die, on average, 15 years earlier than the general population. They’re also more likely to end up homeless and unemployed, and to spend more time in hospital or the criminal justice system. Despite public perception, they are more often victims of violence and tragedy than perpetrators of it. (One example: In Montreal, people with schizophrenia comprise 0.6 per cent of the population, but they represented 25 per cent of those who died in the city’s 2018 heatwave.)

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Kwame McKenzie has spent years studying the role that race plays in mental health.Wellesley Institute

If a certain population – a race-specific population – is more likely to be diagnosed with a devastating, life-altering mental illness, that is not just a public health issue, says Dr. McKenzie, a professor at the University of Toronto and chief executive of the Wellesley Institute, a think tank dedicated to improving health equity. It’s a question of human rights and social justice.

The role of race in health care has long been tainted by discrimination, clinician bias and inequitable treatment; the pandemic has only highlighted a problem that has long existed. In Ontario, for instance, Caribbean-African men are more likely to be involuntarily admitted to hospital for psychosis than other populations, often following a police encounter. Black youth in Ontario also wait much longer for treatment following a first episode of psychosis, putting them at greater risk for poorer outcomes.

But the finding that Black citizens are being diagnosed more often with psychosis is more complex than improving access to care. It goes back more than 50 years and has been the subject of more than 100 peer-reviewed papers. In the United Kingdom and the Netherlands, extensive studies have found rates as much as five times higher in migrants from the Caribbean and Africa than the native-born white population. In Israel, significantly higher rates of psychosis have been found in migrants from Ethiopia. In the United States, African-Americans are more likely to be diagnosed with schizophrenia than white Americans.

Researchers have discovered a similar pattern in Canada. A 2015 Ontario study looking at 10 years of health statistics found higher rates of psychotic disorders in refugees from East Africa and South Asia (about double, and one-and-a-half times higher, respectively) compared to the general population, and an elevated risk among immigrants from the Caribbean and Bermuda.

“This problem is the biggest inequality we have in mental health,” says James Kirkbride, a British psychiatric epidemiologist at University College London who has been studying this issue for 15 years. “We are essentially talking about a disorder that is happening [as much as] 500 per cent more frequently in one group.”

The explanation for this is still being debated. But many researchers have begun to circle one theory in particular – a hypothesis that has ramifications not only for how we diagnose and treat mental illnesses, but what is required to prevent them in the first place. Step back further, and this theory raises uncomfortable questions about the harm inflicted on those deemed by the majority to be outsiders.

What many researchers increasingly believe to be an important risk factor for schizophrenia, this most terrible of brain disorders, is racism.

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Myrna Lashley of McGill University and Toronto court worker Shawn Pendenque have seen how racism affects mental health from both ends. Mr. Pendenque was diagnosed with early-stage schizophrenia in jail. Dr. Lashley is part of an emerging field of research to make mental-health supports more equitable. Read more about their experiences later in this story.Christinne Muschi and Tijana Martin/The Globe and Mail

After the Second World War, according to American psychiatrist Jonathan Metzl, schizophrenia was a disorder related to “emotional disharmony” and diagnosed most often in unhappy housewives and moody artists.

But in the 1960s, the diagnosis shifted. Schizophrenia became a disease defined by rage.

The social and moral values of the time have long influenced what counts as mental illness. Joan of Arc would not be leading an army today; the holy voices she claimed to hear would get her an appointment with a psychiatrist, not an audience with a king. In the 1840s, rebellious slaves on Southern plantations were said to be stricken with “drapetomania,” for the “insanity” of trying to escape to freedom. As historian Elaine Showalter has pointed out, hysteria – an emotional disorder that afflicted only women – just happened to coincide with feminist protests for the right to vote.

In the cultural upheaval of the 1960s, at the peak of the civil rights movement, Dr. Metzl writes in his 2009 book The Protest Psychosis, schizophrenia became a Black man’s disorder.

A magazine ad for medication used to treat psychosis featured the angry face of a Black man with his fist raised and the slogan, “Cooperation begins with Haldol.” In a 1968 article in the Archives of General Psychiatry, two prominent American psychiatrists defined sufferers of the “protest psychosis” as Black men who developed “hostile and aggressive feelings” and “a delusional anti-whiteness” after listening to the speeches of Malcolm X. These symptoms, the authors wrote, “threatened not only their own sanity, but the social order of white Americans.” A second paper, called “Six Years of Sit-Ins,” drew a link between the “stress of asserting civil rights” and psychosis. The very act of protesting, the authors reasoned, led to delusions and grandiose thinking – symptoms included in today’s modern definition of schizophrenia.

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Police halt a group of civil-rights demonstrators near the White House in 1965.The Associated Press

In 1968, the DSM-1, the diagnostic manual for North American psychiatry, referred to patient symptoms as “frequently hostile and aggressive.” It was implicitly racist, given the tenor of the time, writes Dr. Metzl. In effect, “schizophrenia became violent at the same time it became Black.”

Many psychiatrists were critical of the notion of a “protest psychosis,” and in 1980, the third update of the DSM removed language about anger and hostility, along with the male pronouns, from the definition. But the cultural imprint on psychosis, Dr. Metzl contends, was harder to erase.

Yet, even as those post-war white doctors were diagnosing Black patients with the mental illness of challenging a racist society, a talented psychiatrist in colonial Algeria was pointing the blame outward – toward society itself.

In his 1961 book The Wretched of the Earth, Frantz Fanon proposed that racism itself caused mental illness, including psychosis. In an earlier book, Black Skin, White Mask, published in 1952, Dr. Fanon eloquently described his own experience with racism. He wrote about the constant necessity, despite his education and intellect, “to keep one’s place,” and how that eroded his sense of self and “cut away slices of my reality.” Like those white psychiatrists, he spoke of destructive rage – but this rage was a reasonable response to oppression. He described a structure of society where some people lived above the line of humanity, and others were trapped below it. The “psychotic reactions” he saw in his patients, he argued, were directly related to the stress of colonialism.

Dr. Fanon’s work is often cited in current research. The idea that the experience of racism could be traumatic, that it could harm a person’s mental health, that systemic racism could alter how certain groups are diagnosed and treated, should not be surprising today.

Still, it took a while for modern science to get there.

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A patient sits in his room at a Toronto psychiatric institution in 1960. A year later, Frantz Fanon's book The Wretched of the Earth would posit that racism could cause mental illness.Erik Christensen/The Globe and Mail

Schizophrenia is a complicated and controversial illness. Even the word “schizophrenia” – which combines the Greek for “split” and “mind” – is contentious, both for carrying an enduring stigma and being scientifically flawed. Some Western researchers advocate replacing it with “psychosis spectrum disorder,” to better reflect the range and severity of symptoms.

Mental health experts believe a number of factors likely contribute to schizophrenia, including genetics, brain chemistry and social environment – although science is still working hard on the finer details. Genes are a large individual risk factor: People with a parent with schizophrenia have a 10 times higher chance of developing the disorder; having an identical twin with the illness puts your likelihood at 50 times higher.

But genes don’t tell the whole story. Most people with a close family history don’t develop schizophrenia. And unlucky genes haven’t been able to explain why certain ethnic minority groups have higher rates of the illness. There’s no evidence that migrants, as a group, leave home with a higher risk for psychosis tucked in their biological suitcase.

This was one of the earliest theories for why certain ethnic groups had higher rates of schizophrenia – that migrants were bringing the illness with them from their home countries. Over time, that hypothesis has been refuted by epidemiological studies, which have found no evidence of higher rates in places such as the Caribbean, Surinam and India.

Given the skills and resourcefulness it takes to settle in a foreign country, and the mandatory medical screening often required to get there, migrants should be at lower – not higher – risk of severe mental illness. So perhaps it was the trauma of migrating? But that couldn’t explain why risk remained high among the children of migrants born in the host country.

Slicing and dicing the data, however, revealed a clue: The risk of developing psychosis was not equal among all migrants. Newcomers to Britain and the Netherlands who travelled from within Europe, for example, have been found to have significantly lower risks than those coming from outside the continent. Yet even within that non-European group, people from India or other parts of Asia had significantly lower rates than those from Africa or the Caribbean. This pattern continues, to varying degrees, into the second generation.

The search for a clear explanation has been challenging. A problematic birth or a childhood vitamin D deficiency – both associated with a higher risk of schizophrenia – were two possible theories. But Dr. McKenzie says British researchers found that obstetrical complications were not more common among mothers from Africa or the Caribbean, and vitamin D couldn’t explain increased rates among migrants who arrived as adults.

Maybe it was poverty? But poorer countries don’t appear to have higher rates of schizophrenia, and the risk for certain migrant groups remained high, even when researchers adjusted for socioeconomic status.

Another significant risk factor for schizophrenia is living in a city. Researchers are still figuring out why, but some theorize the frenetic landscape, pollution and sense of isolation even in a crowded place could be contributors.

A closer look at cities, however, produced another finding: In areas with ethnic density – a larger concentration of people from the same ethnic group – the rates of schizophrenia were lower, for both generations. A large-scale Swedish study published in Lancet Psychiatry last year analyzed health data from more than 450,000 migrants and their children over at least 20 years. The study found that for visible-minority migrants, a 5-per-cent decrease in ethnic density was associated with a roughly 5-per-cent increase in psychosis risk – a result not shared by white migrants or their children. Studies in Britain, Denmark and the United States have made similar findings.

In the end, after decades of research, a particular theory emerged. The largest risk factor for psychosis didn’t appear to be country of origin or being poor or having migrated or living in a city. It was having darker skin than most of your neighbours.

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A scan of the human brain at the University of Toronto shows various cognitive functions in different colours. Researchers are still untangling how brain chemistry, genetics and social factors can leave some people more at risk for schizophrenia than others.Fred Lum/The Globe and Mail

There is one obvious alternative explanation: Doctors are getting the diagnosis wrong. Schizophrenia can’t be confirmed with a blood test or a brain scan, despite the ongoing efforts of neuroscientists. Although there are standardized scales, a diagnosis is often made by excluding other possibilities, along with a clinician’s own assessment. This makes it susceptible to mistakes and bias.

The role of clinician misdiagnosis continues to be a focus of research, especially in the U.S. Some experts suggest diagnostic tools may be pathologizing behaviour that some cultures and religions would not consider an illness. How people enter the mental health care system, and how easily they find good care once inside, differs between racial groups. American research has found that racialized patients are more likely to be diagnosed with schizophrenia than with mood disorders, even when they have symptoms similar to those of white patients. In Canada, schizophrenia also appears to be experienced differently by race: A four-year study found that compared to white patients diagnosed with schizophrenia, African-Caribbean patients spent more time in a recovered state; were less likely to have continuous, unremitting illness; and were less at risk of suicide and self-harm – but more likely to have suffered imprisonment and compulsory admission.

During her clinical practice, Deidre Anglin, a psychology professor at City University of New York, says she saw examples of colleagues being too quick to diagnose schizophrenia in Black patients, especially those who came in agitated and with a police escort. She says racialized patients, because of their experience in society, including a distrust of the system, may present with a “constellation of symptoms” that aren’t fully reflected in the diagnostic manuals.

Dr. Anglin agrees misdiagnosis plays a role and raises critical questions about race that the field of psychiatry can’t ignore. (The wrong diagnosis could mean, for instance, that a racialized patient doesn’t get the right treatment.) But her work suggests more important factors are the chronic social distress, trauma and discrimination that make mental illness more severe. Psychotic symptoms, she says, are more common even in racialized patients who might be more accurately diagnosed with major depression.

In Britain, she says, some studies have found the link between race and psychosis to be higher than smoking for cancer. “There is no way misdiagnosis alone could capture that much of a difference.“

Dr. Kirkbride describes a British experiment that asked a diverse group of psychiatrists to independently diagnose patients whose ethnicity was hidden. He says higher rates of diagnosis for the racialized groups persisted.

“We all accept that COVID is more prevalent in socially disadvantaged ethnic-minority populations,” he says. “There isn’t a question of misdiagnosis. It is definitely the social determinants of health and the racist pattern of society and people who have been cyclically disadvantaged. I think it is exactly the same explanation for psychosis. But we refuse to believe it. It denies an epidemic that isn’t being treated properly.”

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Shawn Pendenque went to jail for four months after he wrote an angry letter to judges and court officials. He wonders whether, because he is Black, authorities rushed to charge him with sending death threats instead of suspecting he had a mental illness.Tijana Martin/ The Globe and Mail

In 2010, Shawn Pendenque, a Toronto court worker, was charged with sending death threats to a number of judges and court officials.

Mr. Pendenque was born in Canada, to parents who had migrated separately from Dominica and met in Toronto. As a child, he was sexually and physically abused, and by 16, he was living on the street. With the help of LOFT Community Services, a group that provides support and housing to at-risk populations, he eventually became a counsellor for youth – many of them also Black – awaiting trial or sentencing.

He penned the angry, rambling letter and delivered it to court officials – telling them they would “be judged and go to hell” for their part in an unjust system – during what was later diagnosed in jail as a psychotic episode brought on by bipolar schizoaffective disorder, a condition that includes the symptoms of a mood disorder and schizophrenia. Looking back, he wonders if the leap to charge him as a criminal, rather than suspect he had a mental illness, was because he was Black. He went to jail for four months. “They left me with an orange jumpsuit on my back to start over again.”

Mr. Pendenque, who is now a community worker with LOFT and a mental health advocate, believes that observing the biased treatment of young Black teenagers may have triggered something inside him, perhaps a fault line already created by the childhood trauma he’d experienced. He also describes the incongruity of being given the responsibility of his job and at the same time feeling judged inferior because of his race. It’s an exhausting parallel reality, he says. A mind, already wounded, can only bear so much.

Yet, how could the experience of racism do enough damage to the brain that it could result in a severe mental illness?

Aristotle Voineskos, vice-president of research at CAMH and a specialist in schizophrenia, points to evidence that chronic stress weakens the immune system, which has been linked to the development of psychosis. The “social defeat” hypothesis proposes that the long-term experience of being excluded from the majority group eventually leads to chemical changes in the brain. Dr. McKenzie uses the term “thwarted aspirations,” especially for the second generation, who find themselves denied opportunities in the only country they’ve known. This constant race-based stress is also known as “weathering,” and it’s one way to explain why African-Americans, as a group, die earlier of many diseases than white Americans.

A 2014 U.S. study of 644 young, ethnic-minority adults, co-authored by Dr. Anglin, found the experience of racial discrimination was associated with more early, sub-clinical markers for psychosis even when researchers accounted for anxiety and depression. Those threshold symptoms included altered perceptions, paranoia and suspicion, and most commonly cognitive dissonance, which refers to a person thinking or acting in a way that goes against their own beliefs and values – the way you might, for example, if the system meant to help you worked against you instead.

In May, the first Black Canadian National Survey found that among 5,000 respondents, 70 per cent said they experienced racism “regularly or from time to time.” Two-thirds reported being treated with suspicion in the past year; one-fifth reported being unfairly stopped by police in the past month. Nearly half of those surveyed said they’d been treated unfairly by an employer in the past 12 months.

“You wear a mask to get through the days,” says Myrna Lashley, a psychologist and assistant professor at McGill University’s department of psychiatry. She quotes Dr. Fanon’s writings to explain the toll of racism to those who get to “live above the line,” as he once wrote. “You laugh at jokes that aren’t funny,” she says. “You have to have that famous talk with your children that white people don’t have: ‘Even if you just buy a pack of gum at the store, don’t leave without a receipt.’”

Racism harms overtly, Dr. Lashley says, but it also sabotages a person’s social and physical environment. It understandably causes them to question what’s true, to wonder about the motives of their neighbours. Did that person cross the street to get somewhere or to avoid me? Was I seated in the back of the restaurant because I’m Black? Is that police officer just walking by or following me?

How long can anyone’s brain, especially one already dealing with trauma or the challenge of adjusting to a foreign culture, maintain that hyper-vigilance and stay healthy?

“You are holding in that stress all the time. You can’t pill it away. You can’t sleep it away,” says Dr. Lashley. Often, she says, the source of stress – systematic, everyday racism, the micro-agressions that have macro implications – is dismissed or denied, adding to the trauma. “It becomes the knee on our neck, and we can’t breathe.”

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Racism makes people question what's true and the motives of the people around them in a way that can be traumatizing, psychologist Myrna Lashley says.Christinne Muschi /The Globe and Mail

Pile those suffocating, demoralizing, exhausting incidents of discrimination on a life already complicated by a troubled childhood, a family history of illness or isolated-newcomer status, and the research suggests that the narrative is significantly more likely to lead to a diagnosis of schizophrenia.

Still, Dr. Voineskos cautions against over-simplifying a complex illness. The vast majority of people victimized by racism do not go on to develop psychosis, and patients diagnosed with psychosis, such as Mr. Pendenque, typically present with a unique combination of risk factors.

Also, what kind of racism increases risk the most? More recent studies suggest systematic racism may have a larger effect than the direct experiences of discrimination, says Hannah Jongsma, a senior scientific researcher at the Veldzicht Center for Transcultural Psychiatry in the Netherlands. In a 2020 paper she co-authored, on ethnicity and psychosis, the two largest specific risk factors appeared to be social disadvantage and linguistic distance from the native population – barriers that make it harder to shed one’s outsider status.

Parsing the difference between cause and correlation is tricky with this kind of research, particularly with population-based studies that analzye groups rather than individuals. To find a causal effect, not just a correlation, researchers often look for a dose-response: The bigger the dose, the higher the response.

Some studies have suggested this may exist for discrimination and symptoms of psychosis, although it remains a work in progress.

An older British study, co-authored by Dr. McKenzie, recruited people with no history of psychosis, recorded their experiences with discrimination and their level of perceived racism, and followed them for three years. At the end, the study found a link between the onset of delusional thinking and higher rates of discrimination, from 0.5 per cent for those reporting no discrimination to 2.7 per cent for people reporting more than one type of discrimination.

“Not one person would have an issue with saying that if you went to war, you can have a mental health problem from the trauma,” says Dr. McKenzie. “Hardly anyone on Bay Street has trouble with the idea that stress and high pressure will lead some people to anxiety and substance issues.”

And yet people remain skeptical – or at least surprised – when he explains the association between racism and psychosis. “So just about every other type of trauma can lead to mental illness. And racism can’t?”

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Illustration by Rachel Wada

Society is not trapped by genes or confined by history. This is a problem that society can solve.

“We can do something about the social factors right now,” says Jai Shah, a McGill professor and psychiatrist who specializes in schizophrenia.

This requires addressing issues such as housing, employment opportunities, education barriers – all the structural elements of society that disadvantage certain racial groups. Some experts propose more interventions to help youth better weather racial discrimination. Research suggests migrants are more protected from risk when they have a stronger sense of belonging in their communities. Acknowledging the elevated rates of diagnosis would also mean targeting early-intervention resources to populations at higher risk. Dr. Kirkbride contends that, for ethnic communities, eliminating structural racism could reduce the incidence of psychosis by as much as 70 per cent.

More recently, there has been a new focus on improving access to the mental health care system for racialized communities and delivering more culturally sensitive treatment once patients are in care. Ottawa has targeted millions of mental health dollars to race-based organizations. In February, CAMH announced a new strategy, co-led by Dr. McKenzie, to reduce systematic racism for Black patients and staff.

A team of researchers at McGill are developing culturally sensitive training for clinicians. “Patients feel that they are not being heard, their pain isn’t being recognized, that it is seen as something in the past,” says Dr. Lashley. ”It is in the past for people who haven’t lived it. It is not in the past for people who endure it from day to day.”

Dr. Anglin adds mental health clinicians also need to focus on social risk factors as much as individual symptoms and become louder advocates for wider social change. And policy makers and employers need to correct the systemic barriers that cause chronic stress and mental illness.

“‘Not being racist’ is not enough,” says Dr. Anglin. “You can’t just be neutral.” Not when the cure lies with society.

The Decibel: Racism and your mental health

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