People living with severe mental illness face a much higher risk of dementia and stroke than the general population, and these risks appear far earlier in life than most doctors would expect, according to a study published in the journal European Neuropsychopharmacology. The authors suggest that mental health care needs to go hand in hand with regular checks on the brain and heart, right from a young age.
What the Researchers Found
The team looked at around 177,000 people diagnosed with schizophrenia, bipolar disorder, or major depression, and compared them with about 517,000 people without a psychiatric diagnosis. They then examined rates of dementia and stroke across age groups from 20 all the way up to 99.
The results were striking. At every age studied, severe mental illness was linked to a higher risk of dementia. The gap was especially dramatic in younger adults. People aged 30 to 39 with a severe mental health condition were more than 20 times more likely to have dementia than those without such a diagnosis.
Co-lead author Dr Michele De Prisco (of the Hospital Clínic-IDIBAPS and University of Barcelona) explained: “Although dementia remains rare in that 30 to 39 age group overall, the size of the difference associated with mental illness was notable. For every 100,000 people without a severe mental illness, about 24 had dementia at ages 30-39, compared with about 550 among those with a severe mental illness.” That translates to a 20-fold difference in odds, even though the actual percentages are small (0.55% versus 0.02%).
The pattern held into old age too. Adults aged 80 to 89 with severe mental illness were still around four times more likely to have dementia. For stroke, people aged 40 to 49 with severe mental illness had nearly three times the odds of an ischaemic stroke compared with those without a psychiatric diagnosis.
A Wake-Up Call for Clinicians
Dr De Prisco believes the findings should change how doctors approach mental illness. “One of the most important contributions of our findings is to raise awareness that conditions such as dementia and stroke, which in clinical practice are often thought of as problems of old age, can also emerge in people who are much younger. That should put clinicians on alert.”
Roughly a billion people worldwide live with some form of mental illness, and at least 300 million have a severe condition such as schizophrenia, bipolar disorder, or major depression. Given those numbers, the researchers argue that mental health care needs to be woven together with regular monitoring of the brain and heart.
“These findings reinforce the need to think about severe mental illness as a whole-person health issue, not only a mental health diagnosis,” Dr De Prisco said. “What we are seeing is that risks linked to subsequent dementia and stroke may appear much earlier in life than many people expect, which means prevention, monitoring and coordinated care should also begin earlier.”
Important Caveats and Next Steps
The study is a snapshot in time, not a long-term follow-up, so it shows a strong link rather than proof that mental illness directly causes dementia or stroke. The researchers say the next step is to track patients over time, and then to build and test care systems that combine mental and physical health support.
Commenting independently, Professor Kamilla Miskowiak of the University of Copenhagen said the findings underline the importance of paying attention to brain health in mental illness care. “These findings highlight the importance of considering cognitive and brain health as key treatment targets in people with severe mental illness. Cognitive impairment affects most people with schizophrenia and around half of individuals with bipolar disorder and major depression, often even when psychiatric symptoms are stable.”
She added: “Better integration of mental, cognitive, and physical health care could help improve both quality of life and long-term health outcomes for these patients.”
The message from the study is clear: severe mental illness is not just a matter of the mind. It touches the whole body, and often much earlier than expected.
De Prisco M, Oliva V, Sanchez-Valle R, et al. Age-stratified associations between severe mental illness, dementia, and ischemic stroke: findings from the PADRIS-PRESTO cohort. European Neuropsychopharmacology, 110, 112850. https://doi.org/10.1016/j.euroneuro.2026.112850