byUniversity of Oslo

Credit: Pixabay/CC0 Public Domain

Researchers from the Center for Precision Psychiatry at the University of Oslo and Oslo University Hospital have discovered extensive genetic links between neurological disorders like migraine, stroke and epilepsy, and psychiatric illnesses such as schizophrenia and depression. Published inNature Neuroscience, thisresearchchallenges longstanding boundaries between neurology and psychiatry and points to the need for more integrated approaches to brain disorders.

"We found that psychiatric and neurological disorders sharegenetic risk factorsto a greater extent than previously recognized. This suggests that they may partly arise from the same underlying biology, contrasting the traditional view that they are separate disease entities. Importantly, the genetic risk was closely linked to brain biology," states Olav Bjerkehagen Smeland, psychiatrist and first author.

The team analyzedgenetic datafrom close to 1 million individuals with a wide range of psychiatric or neurological conditions. Thislarge datasetmade it possible to map both shared and disorder-specific genetic signals. "The findings are consistent with what we see clinically: patients often present with overlapping symptoms across neurology andpsychiatry," says Professor Ole Andreassen, leader of the Center for Precision Psychiatry. "Our results support a more unified view of neurological and psychiatric disorders."

According to Smeland, the study suggests that patients could benefit from treatment strategies that take both biological and mental aspects into account. "We should ask whether patients receive the best care when neurology and psychiatry operate in parallel rather than together," he says.

Study design. Credit:Nature Neuroscience(2025). DOI: 10.1038/s41593-025-02090-2

While the study found substantial genetic overlap, the disorders still displayed partly distinct biological signatures. "For instance, genetic susceptibility to stroke was associated with risk factors for thrombosis, while epilepsy was connected to neurons—the brain's nerve cells. The genetic risk for Alzheimer's disease and multiple sclerosis, by contrast, was tied to theimmune system, which also influences the nervous system. The genetic risk for psychiatric illnesses was consistently linked to neurons. This tells us that neurological and psychiatric disorders are heterogeneous, but may still be connected within a common biological framework," Smeland explains.

While distinctions between neurological andpsychiatric disordersdo exist, this study paves the way for a more holistic understanding of brain disorders. "I believe that improved knowledge exchange and closer collaboration between psychiatry andneurologycould substantially benefit patients, " Smeland states.

More information: Olav B. Smeland et al, A genome-wide analysis of the shared genetic risk architecture of complex neurological and psychiatric disorders, Nature Neuroscience (2025). DOI: 10.1038/s41593-025-02090-2 Journal information: Nature Neuroscience

Provided by University of Oslo