Even as overall psychosis rates level off among older Canadians, younger generations find themselves under siege. The incidence of psychotic disorders has shot up dramatically, according to a broad new population-based study in the Canadian Medical Association Journal.
“While some of the increases in psychotic disorder diagnoses in people born in the 1980s and 1990s may reflect improvements in care and early diagnosis, these patterns raise important concerns about generational changes in exposure to factors that increase the risk of psychotic disorders,” lead author and University of Ottawa assistant professor Daniel Myran, MD, explained. “We don’t yet know what’s driving these changes, and it’s likely there isn’t a single explanation.”
Digging Through Health Records
Analyzing health records from more than 12 million Ontario residents born between 1960 and 2009, the researchers uncovered higher diagnosis rates of psychotic disorders among those born in the 1990s and early 2000s. Worse still, clinicians diagnosed these younger cohorts at earlier ages than people born even a few decades earlier.
More specifically, the teams discovered that between 1997 and 2023, the annual incidence of psychotic disorders jumped 60% among adolescents and young adults between the ages of 14 and 20. During that same timeframe, rates tumbled – or at least held steady – among adults 21 to 50. The study’s authors suggest that this masks a stark generational divide that reveals itself only when you look at these birth cohorts separately.
The researchers focused on non-affective psychotic disorders, a category often used early in illness or before symptoms clearly fit a specific diagnosis. Taken together, these conditions influence perception, thought, and behavior. They also drive disability, premature mortality, and high health-care use.
Using age-period-cohort modeling to unravel the effects of aging, calendar time, and generation, the researchers found that people born between 2000 and 2004 had a 70% higher incidence of schizophrenia than those born between 1975 and 1979. Rates of psychosis not otherwise specified spiked even more sharply, appearing nearly three times more often in the youngest cohort.
By age 20, 0.55% of people born between 2000 and 2004 had already received a diagnosis of a psychotic disorder. That’s more than double the proportion among those born adjust one generation earlier. By age 30, people born in the early 1990s showed a prevalence about 38% higher than those born in the late 1970s.
At the same time, the average age at diagnosis has been falling. Among cohorts that could be followed nonstop into adulthood, the mean age at diagnosis fell from about 25 years for those born in the late 1970s to a little more than 23 years for those born in the early 1990s.
Wrestling with Explanations
Myran and his colleagues figure that this shift – at least to some extent – probably reflects better access to care. Ontario dramatically expanded early psychosis intervention programs over the past two decades. In the process, the province expanded the number of specialized services for young people experiencing first-episode psychosis. Earlier assessment and treatment could obviously lead to younger ages at diagnosis – and to more provisional diagnoses.
But the authors add that better detection alone can’t explain the scale or consistency of the cohort effects. Even after accounting for shifts in diagnostic practices, better access to care, and robust administrative databases, the generational increases persisted.
Researchers noted similar patterns in both outpatient and hospital diagnoses. It could indicate that the trend doesn’t simply reflect shifting care settings. Instead, the findings raise the startling possibility that younger generations are living with higher underlying risk.
Which Factors Matter Most?
A growing body of research points to social and environmental exposures that could be at play. These include increased substance use, along with socioeconomic stress, urbanization, migration-related adversity, and maybe even some adverse childhood experiences.
Changes in parental age, maternal health, and neonatal survival might also be reshaping the landscape of neurodevelopmental vulnerability.
Myran and his team can’t pinpoint which factors make the biggest difference. As a result, the authors warn that younger cohorts haven’t yet been tracked into midlife, when some psychotic disorders start to emerge. Earlier cohorts might also appear undercounted if people developed symptoms early on but never re-engaged with the health system.
“We don’t yet know what’s driving these changes, and it’s likely there isn’t a single explanation. Understanding what’s behind this trend will be critical to prevention and early support,” Myran added.
Either way, it’s a difficult pattern to ignore. Clinicians, policymakers, and families must recognize that psychosis isn’t going anywhere. In fact, it might be showing up sooner – and affecting more young people.
Further Reading
Exercise Reduces Dysphoria in Clinical High Risk for Psychosis
