Nikhil Prasad Fact checked by:Thailand Medical News Team May 12, 2026 25 minutes ago
Medical News: Cognitive problems such as poor memory, confusion, slow thinking, and difficulty concentrating are common in people suffering from severe mental illnesses like depression, bipolar disorder, and schizophrenia. Now, researchers in Italy say certain blood biomarkers linked to brain damage and Alzheimer’s disease could help doctors better understand why these symptoms occur and may even help distinguish psychiatric illnesses from early dementia.
The new review study was conducted by scientists from the IRCCS Istituto Centro San Giovanni di Dio Fatebenefratelli in Brescia, Italy, the University of Brescia, and the institute’s Psychiatry Unit and Memory Clinic.
New blood biomarkers may help doctors detect hidden brain damage and early dementia risks in people with severe
mental illnesses.
Blood Tests Could Transform Mental Health Diagnosis
The researchers examined growing evidence surrounding blood biomarkers known as ATX(N) biomarkers. These include neurofilament light chain (NfL), glial fibrillary acidic protein (GFAP), amyloid beta, and tau proteins. These markers are already widely studied in Alzheimer’s disease and other forms of dementia because they reflect nerve cell injury, brain inflammation, and abnormal protein buildup.
Scientists now believe these same biomarkers may also play a role in psychiatric disorders.
Severe mental illnesses often cause cognitive decline that resembles early dementia. Patients may struggle with memory, attention, planning, learning, or decision-making. In many cases, doctors have difficulty determining whether the symptoms are caused purely by mental illness or whether an underlying neurodegenerative disease is beginning to develop.
The researchers say blood biomarkers could eventually provide a faster and less invasive way to identify what is truly happening inside the brain.
Depression Linked to Signs of Brain Injury
The review found especially strong evidence in major depressive disorder.
Many studies showed that patients with severe or treatment-resistant depression had elevated levels of NfL in their blood. NfL is released when nerve fibers in the brain are damaged. Higher levels were repeatedly associated with worse memory, slower processing speed, impaired executive function, and more severe depressive symptoms.
Researchers also found that people with late-life depression often showed abnormal levels of GFAP, a marker connected to inflammation and dysfunction of astrocytes, which are supportive cells in the brain. Increased GFAP levels were linked to poorer scores on cognitive tests and greater decline in mental performance.
Even more concerning was evidence that some depressed individuals showed altered amyloid beta and tau protein patterns similar to those observed in Alzheimer’s disease. Several studies noted reduced amyloid beta 42/40 ratios and increased tau-related abnormalities in patients with depression, particularly older adults with cognitive impairment.
This
> Medical News report highlights that these findings may explain why people with chronic depression sometimes experience accelerated brain aging and face a higher risk of developing dementia later in life.
Bipolar Disorder Shows Progressive Brain Changes
The study also found growing evidence of ongoing brain injury in bipolar disorder.
Patients with bipolar disorder frequently experience difficulties with verbal learning, memory, attention, and executive functioning. Blood tests revealed that higher NfL levels were consistently linked to poorer cognitive performance and longer disease duration.
Researchers noted that NfL levels often rose during active mood episodes and appeared higher in patients with more severe illness progression. This suggests that repeated manic or depressive episodes may gradually damage brain connections over time.
Evidence for amyloid and tau involvement in bipolar disorder remains less clear. However, some younger patients with accelerated biological aging showed abnormal amyloid patterns, raising concerns that certain subgroups may face increased neurodegenerative risk.
Schizophrenia and Cognitive Decline
Schizophrenia also showed evidence of biological brain abnormalities, though the findings were more inconsistent.
Patients commonly suffer from problems involving memory, attention, processing speed, and decision-making. Some studies found elevated NfL levels in acutely ill or treatment-resistant schizophrenia patients, especially those with severe symptoms and reduced daily functioning.
Researchers also observed altered GFAP and tau protein levels in some schizophrenia patients, suggesting that inflammation and disrupted brain-cell structure could contribute to cognitive decline.
Interestingly, one study found that brain stimulation therapy improved working memory while also increasing phosphorylated tau levels, hinting that tau proteins in schizophrenia may behave differently than in Alzheimer’s disease.
Blood Biomarkers May Help Prevent Misdiagnosis
One of the most important findings involved the potential use of these blood tests to separate psychiatric disorders from dementia.
Conditions like frontotemporal dementia and dementia with Lewy bodies are often mistaken for schizophrenia, depression, or bipolar disorder because symptoms overlap heavily. Some dementia patients spend years being treated for psychiatric illness before receiving the correct diagnosis.
The review found that NfL blood levels were usually far higher in true neurodegenerative diseases than in psychiatric disorders. In several studies, these biomarkers showed strong accuracy in distinguishing frontotemporal dementia from psychiatric illnesses.
Conclusions
The researchers concluded that blood biomarkers could eventually revolutionize psychiatric medicine by giving doctors measurable biological clues about brain health instead of relying only on symptom-based diagnosis. While the evidence is strongest for depression, growing findings in bipolar disorder and schizophrenia suggest that hidden neurodegenerative processes, inflammation, and nerve-cell damage may contribute far more to mental illness than previously believed.
However, scientists caution that more long-term studies are needed before these biomarkers can become routine clinical tools. Future research may help doctors identify high-risk patients earlier, personalize treatments, and potentially slow cognitive decline before permanent brain damage occurs.
The study findings were published in the peer reviewed International Journal of Molecular Sciences.
https://www.mdpi.com/1422-0067/27/10/4260
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Medical News.
Read Also:
https://www.thailandmedical.news/articles/mental-health
https://www.thailandmedical.news/articles/alzheimer,-dementia-
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