Severe Mental Illness Linked to Early Dementia and Stroke Risk

For anyone comparing mental health treatment facilities for a family member living with severe mental illness, a large new study makes a case for asking a question that rarely comes up on a tour. Does this program monitor physical health, or only psychiatric symptoms?

Research published in the September 2026 edition of European Neuropsychopharmacology found that people with severe mental illness carry a substantially higher risk of dementia across adulthood, and a significantly elevated risk of stroke in early and middle adulthood.

The findings come from health records in Catalonia, Spain, and were presented by the European College of Neuropsychopharmacology.

Mental Health and Physical Health Are Not Separate Tracks

Researchers examined records from nearly 700,000 people. About 177,000 had a diagnosis of schizophrenia, bipolar disorder, or major depression. Roughly 517,000 had no psychiatric diagnosis and served as controls.

Comparing rates of dementia and stroke across age bands from 20 to 99, the team found a significant association between severe mental illness and dementia at every age studied.

The size of the gap in early adulthood is the finding that stands out. Adults aged 30 to 39 with severe mental illness showed more than 20 times the odds of dementia compared with people without a psychiatric diagnosis.

Dr. Michele De Prisco, co-lead author from Hospital Clinic-IDIBAPS and the University of Barcelona, put that number in proportion. Dementia is rare in that age group overall.

For every 100,000 people without severe mental illness, about 24 had dementia at ages 30 to 39. Among those with severe mental illness, the figure was about 550. In prevalence terms that is 0.55 percent compared with 0.02 percent.

The gap narrows with age but does not close. Among adults aged 80 to 89, people with severe mental illness still had roughly four times the odds of dementia.

For stroke, adults aged 40 to 49 with severe mental illness had nearly three times the odds of ischemic stroke compared with controls.

What the Study Can and Cannot Tell Us

This point matters and should not get lost. The study was cross-sectional, meaning it captured a snapshot rather than following individuals over time. It demonstrates an association, not cause and effect.

De Prisco said the next step is longitudinal work following individual patients over time, alongside developing systems that integrate mental and physical care and then testing whether those systems actually work.

What the researchers argue the findings do support is a shift in expectations. De Prisco said the results reinforce thinking about severe mental illness as a whole-person health issue rather than only a mental health diagnosis, and that prevention, monitoring, and coordinated care should begin earlier than they typically do.

Why Severe Mental Illness Calls for Integrated Treatment

Severe mental illness affects at least 300 million people worldwide, within a broader population of roughly a billion people living with mental illness.

At that scale, the authors say, integrating general health care into psychiatric care is a practical necessity rather than an aspiration.

This is the same logic behind dual diagnosis treatment, which addresses co-occurring disorders such as depression and a substance use disorder together rather than in sequence.

Treating one condition while ignoring another that interacts with it tends to produce worse outcomes in both. The Catalonia findings extend that reasoning to neurological and cardiovascular health.

Professor Kamilla Miskowiak of the University of Copenhagen, commenting independently, said the findings highlight cognitive and brain health as treatment targets in their own right.

She noted that cognitive impairment affects most people with schizophrenia and around half of people with bipolar disorder or major depression, often even when psychiatric symptoms are stable.

Screening for cognitive decline and addressing modifiable risk factors, including cardiovascular problems, belongs in routine care, she said.

Interventions such as cognitive remediation can improve cognitive function, though she added that more effective treatments targeting cognition are still needed.

Treatment Options for Mental Health and Addiction

Comprehensive behavioral treatment centers vary widely in how much medical oversight they build in. Residential treatment centers typically include on-site medical staff and routine health monitoring.

Outpatient and intensive outpatient programs usually coordinate with a primary care provider instead, which works well when that relationship exists and less well when it does not.

Evidence-based therapies including cognitive behavioral therapy, dialectical behavior therapy, and trauma-focused approaches remain the core of care for most psychiatric conditions, often alongside medication management.

Cognitive remediation is a more targeted option where cognitive symptoms are prominent.

Finding Comprehensive Treatment

When comparing mental health treatment facilities, ask directly whether the program tracks blood pressure, metabolic markers, and cognitive function alongside psychiatric symptoms, and how it coordinates with primary care after discharge.

For anyone with co-occurring conditions, ask whether dual diagnosis treatment is delivered by one integrated team or by separate providers who rarely speak.

TCD.com lists treatment centers offering mental health, behavioral health, and dual diagnosis care with details on services, levels of care, and payment.