L’ESSENTIEL
- Several common characteristics have been identified between schizophrenia and bipolar disorder.
- Studying this phenomenon, researchers have discovered a common biomarker for both conditions in white matter.
- This biomarker could help better identify individuals at risk of psychosis and potentially lead to the development of new therapeutic approaches.
While the symptoms of schizophrenia and bipolar disorder differ significantly – schizophrenia is characterized by alterations in thought and emotional patterns, hallucinations, or delusions, while bipolar disorder involves extreme mood swings between periods of hyperactivity and depressive episodes – increasing evidence suggests underlying biological similarities. This has led to the hypothesis of a “spectrum of psychosis.”
Researchers from the University of Florence, Geneva University Hospitals, and the École Polytechnique Fédérale de Lausanne investigated this idea and identified a shared biomarker present in both disorders.
Disruptions in White Matter of the Corpus Callosum
The study, published in Nature Mental Health, analyzed brain scans (MRIs) collected over the past 30 years. The research team aimed to determine if white matter in patients with schizophrenia or bipolar disorder showed similar changes or distinct anomalies, while accounting for age and sex.
Analysis revealed common alterations in white matter within a brain region called the corpus callosum, which connects the left and right hemispheres. “This alteration was observed across the entire spectrum of psychoses, and not just for a single diagnosis,” explained Dr. Saccaro, a co-author of the study, to Medical Xpress.
“Importantly, these results remained significant (and in some cases, became more pronounced) after accounting for age and sex, suggesting they are likely not solely explained by the duration of the illness or aging. This supports the idea that disruptions in brain connectivity could be a fundamental biological characteristic of psychosis.”
This Common Biomarker Could Facilitate Screening for At-Risk Individuals
Beyond supporting the concept of a psychosis spectrum, the white matter alteration in the corpus callosum may serve as a biomarker for both mental health conditions. This discovery could also improve the identification of individuals at risk of developing a mental disorder involving psychotic episodes. Early identification is crucial for timely intervention and improved patient outcomes.
The findings also open avenues for exploring new treatments. “Our study suggests that future interventions could target these disruptions in connectivity (of white matter) frequently associated with psychosis,” Dr. Saccaro added. “In the long term, such approaches could even help reduce the risk of symptom onset in vulnerable individuals.”
Researchers plan to conduct further meta-analyses of MRIs from individuals with schizophrenia and bipolar disorder to determine whether white matter alterations appear before or after the onset of initial symptoms. “This would help determine whether it is an early vulnerability factor rather than a consequence of the illness itself,” the specialist noted.
