Schizophrenia is a serious mental health condition that affects how a person thinks, feels, and behaves.
People with schizophrenia may experience symptoms such as hearing voices that are not there, believing things that are not true, confused thinking, and a loss of interest in everyday life. The illness can also affect memory, attention, and the ability to communicate clearly with others.
Although schizophrenia has been studied for many years, diagnosing it remains difficult. Unlike many other medical conditions, there is currently no simple laboratory test that can confirm the disease.
Instead, doctors usually rely on observing a person’s behavior and symptoms over time. They may also need to rule out other possible causes, such as substance use, neurological conditions, or other mental health disorders.
Because symptoms can vary widely between individuals, it may take months for doctors to reach a confident diagnosis. During this time, patients may struggle without receiving the most appropriate treatment. Early diagnosis is important because treatment and support can help reduce symptoms and improve quality of life.
For this reason, scientists have been searching for biological markers, also known as biomarkers, that could help doctors identify schizophrenia more quickly and more accurately.
A research team led by scientists at Rutgers University in New Jersey has now discovered promising clues that may help. Their findings were published in the journal Science Advances.
The researchers explored whether cells collected from inside the mouth could reveal signs of schizophrenia. These cells, known as buccal cells, line the inside of the cheeks and can be collected easily using a simple swab. This method is quick, painless, and does not require any invasive medical procedure.
To investigate the idea, the research team recruited 54 volunteers. Half of the participants had already been diagnosed with schizophrenia, while the other half were healthy individuals without the condition. The two groups were carefully matched by age, race, and gender to ensure that the results would be as reliable as possible.
The scientists collected cheek swab samples from each participant and analyzed the cells in the laboratory. They used a technique called reverse transcription quantitative polymerase chain reaction, often shortened to RT‑qPCR. This method allows researchers to measure the activity of specific genes by examining the amount of RNA present in the sample.
Genes carry instructions that tell cells how to make proteins. By measuring RNA, scientists can determine how active a gene is and whether it is producing more or less of a certain protein.
The research team focused on three genes that previous studies had linked to schizophrenia risk. After measuring gene activity, they also used another laboratory method called mass spectrometry to examine the proteins produced by these genes.
The results revealed clear differences between the two groups.
One gene, called Sp4, showed much higher activity in people with schizophrenia compared with the healthy participants. The Sp4 gene is known to play an important role in brain development and the regulation of certain brain functions.
The researchers also noticed that people with higher Sp4 activity tended to have more severe symptoms of schizophrenia. In particular, increased activity of this gene was associated with stronger hallucinations and delusional thinking.
In addition to Sp4, the scientists found increased levels of a protein called HSP60 in the cheek cells of patients with schizophrenia. HSP60 appears to be influenced by the activity of the Sp4 gene and may be part of the same biological pathway.
The discovery of these two markers suggests that they may serve as potential biological indicators of schizophrenia.
One interesting reason why cheek cells may reveal information about brain health is related to early human development. Both the central nervous system and the cells lining the inside of the mouth develop from the same early tissue layer in the embryo, called the ectoderm. Because of this shared origin, changes that affect the brain may sometimes also appear in cheek cells.
This biological connection gives scientists a unique opportunity to study brain-related conditions using simple samples from the mouth.
Although the findings are promising, the researchers emphasize that the study involved a relatively small number of participants. Larger studies will be needed to confirm whether these biomarkers are reliable and specific to schizophrenia.
Future research will also need to determine whether the same markers appear in other mental health conditions. This step is important because doctors must be able to distinguish schizophrenia from other disorders that may cause similar symptoms.
If future studies confirm the results, a cheek swab test could offer several important advantages. Doctors might be able to identify schizophrenia earlier, monitor how the disease changes over time, and evaluate how well treatments are working.
Such a test could also help reduce the uncertainty that many patients experience during the diagnostic process.
When reviewing these findings, it is important to remember that schizophrenia is a complex condition influenced by many genetic, biological, and environmental factors. A single biomarker may not provide a complete diagnosis on its own.
However, biological tests combined with clinical observation could significantly improve the accuracy and speed of diagnosis.
This study represents an important step toward understanding the biological mechanisms behind schizophrenia. By identifying measurable signals outside the brain, scientists are moving closer to developing practical tools that may one day help doctors diagnose and manage this challenging mental illness more effectively.
If you care about depression, please read studies that vegetarian diet may increase your depression risk, and Vitamin D could help reduce depression symptoms.
For more information about health, please see recent studies that ultra-processed foods may make you feel depressed, and these antioxidants could help reduce the risk of dementia.
The study is published in Science Advances.
Copyright © 2026 Knowridge Science Report. All rights reserved.
