Shared brain biomarker for schizophrenia, bipolar disorder identified

A collaborative study by researchers from the University of Florence in Florence, Italy, Geneva University Hospital  in Geneva, Switzerland and the École Polytechnique Fédérale de Lausanne (EPFL) in Lausanne, Switzerland has provided new evidence supporting the existence of a psychosis spectrum. The meta-analysis suggests that schizophrenia and bipolar disorder (BD) share significant neurological commonalities, particularly within the brain’s white matter.

The researchers are Giuseppe Pierpaolo Merola, Livio Tarchi, Luigi Francesco Saccaro, Farnaz Delavari, Camille Piguet, Dimitri Van de Ville, Giovanni Castellini and Valdo Ricca. Their paper was published in Nature Mental Health.

Breaking the silo of psychiatric research

Historically, neuroimaging research has treated schizophrenia and bipolar disorder as distinct entities. However, Merola, Tarchi, Saccaro, Delavari, Piguet, Van de Ville, Castellini and Ricca analyzed three decades of mgnetic resonance imaging (MRI) data to find overlapping alterations.

By reviewing 30 years of brain imaging, the team sought to identify shared brain signatures that persist across both conditions, regardless of the patient’s age or sex.

The most significant discovery was the identification of white matter alterations in the corpus callosum, the primary bridge connecting the left and right hemispheres of the brain. This structural change appears to be a candidate biomarker for both disorders.

Implications for diagnosis and prevention

The study’s findings offer several potential breakthroughs for mental healthcare:

• Risk Assessment: Identifying these alterations could help clinicians evaluate an individual’s risk of developing disorders involving psychotic episodes.
• New Tools: The data could lead to the development of more precise diagnostic tools and personalized treatment strategies.
• Predictive Methods: It may improve the ability to predict the onset of psychotic episodes before they occur.

The research team plans to transition to longitudinal studies, tracking high-risk individuals over time. This next phase aims to determine if these white matter differences are present before the first clinical symptoms of schizophrenia or BD emerge, or if they develop as the conditions progress.