While there is no one blood test to detect schizophrenia, regular blood testing can provide important information about a person’s schizophrenia treatment and overall well-being.

Schizophrenia can affect many aspects of a person’s well-being, including their ability to regulate emotions and perceptions of the outside world. It is a complex psychiatric disorder that can lead to hallucinations, paranoia, and other physical and mental health concerns.

People with schizophrenia may undergo a variety of tests over the course of diagnosis and treatment, including blood tests. Understanding how all these tests fit into a schizophrenia care plan can be overwhelming if a medical professional does not explain them thoroughly, which may leave some people feeling frustrated and isolated.

This article focuses on understanding the role of blood tests in schizophrenia care, including what types of tests a person can expect to receive. It also examines emerging research on the use of blood tests to help support other aspects of schizophrenia care, including diagnosis and treatment.

Diagnosing schizophrenia can be complicated. At present, there is no blood test that can diagnose schizophrenia. The condition is typically diagnosed by a psychiatric professional, such as a psychiatrist, who carefully reviews a person’s symptoms and medical history to determine if schizophrenia is likely.

“We often do blood tests when people present with psychosis to check their overall health and rule out some disorders that can cause psychotic symptoms,” said Jennifer Zick, MD, PhD, a psychiatry resident at the University of Minnesota, MN.

“Psychosis refers to symptoms like delusions, paranoia, and hallucinations,” she explained. “Psychosis can be present with several other psychiatric disorders, including depression and bipolar disorder, and it can be caused by substances, some medications, and other medical conditions.”

By using blood tests, psychiatrists can rule out other potential causes of psychosis and mental health symptoms. This helps ensure the symptoms a person is experiencing are due to schizophrenia and not another cause.

A medical professional may also perform other types of testing during diagnosis, including cognitive testing and brain imaging. As with blood tests, none can definitively prove a person has schizophrenia. However, the collective results from these tests can help psychiatrists create a clearer picture of what is happening in a person’s brain.

People receiving medication for schizophrenia often have blood testing done regularly over the course of treatment.

“We often do blood tests to monitor the effects of medications that are used to treat schizophrenia,” said Dr. Zick. Some types of medications can cause problematic side effects related to metabolic and immune health, she explained. These include:

  • weight gain
  • insulin resistance
  • hyperglycemia, also called high blood sugar
  • changes in lipid levels, such as high cholesterol
  • changes in immune cell counts

For most people receiving antipsychotic medications, experts recommend blood testing for fasting glucose and lipid levels every 6–12 weeks. A doctor may also order a complete blood count to assess overall health.

These tests can help detect early changes to a person’s health and offer healthcare professionals an opportunity to intervene earlier if issues arise. Heart disease is among the leading causes of death in people with schizophrenia, and early intervention may be able to help prevent these effects.

“We also may check the amount of a medication in someone’s blood in order to adjust the dose since everyone metabolizes medications differently, and sometimes the same dose can lead to different levels in different patients,” added Dr. Zick.

“It is called therapeutic drug monitoring (TDM), and it can help to determine if there is enough medication on board to be effective,” explained Leslie Citrome, MD, MPH, a clinical professor of psychiatry and behavioral sciences at New York Medical College. “Or, if levels are excessively high, the dose can be reduced.”

The precise cause of schizophrenia remains unclear. In general, experts think the cause is due to a combination of genetics and environmental factors and that genetics plays an important role in its development. A person’s risk of developing schizophrenia is more than six times higher if they have a close relative with the condition. However, most people diagnosed with schizophrenia do not have a family history of psychosis.

Environmental factors may also play a role in the development of schizophrenia. These may include such things as:

  • being born and raised in an urban area
  • cannabis use
  • infection
  • complications during pregnancy

Experts use results from blood tests to better understand what causes schizophrenia. For instance, through these kinds of studies, researchers have found that inflammation is common in people with schizophrenia.

By identifying specific molecules and cells linked to schizophrenia, scientists hope to one day better understand what causes the condition and, in turn, find potential ways to treat these underlying causes.

“The development of new biomarkers will be most useful if it gives us information on the types of treatments that may be helpful in the future,” Dr. Zick noted.

While such a test is not yet ready, some researchers are working to identify certain blood markers that can diagnose schizophrenia. Studies have examined a variety of different potential biomarkers for schizophrenia, including:

It is unlikely a test based on these factors will ever be able to diagnose schizophrenia on its own, but the hope is that a biomarker-based blood test could help psychiatrists diagnose schizophrenia faster and with greater confidence.

Other researchers are also studying the use of blood-based markers to monitor response to schizophrenia medications, which could someday help support treatment decision-making for people with schizophrenia.

Other types of testing may also support schizophrenia diagnosis and treatment in the future. Dr. Zick suggested that tests that measure activity within the brain, such as functional MRI or electroencephalography (EEG), could help researchers better understand how different parts of the brain are communicating with each other.

“There have been many studies that indicate differences in the function of the brains of people with schizophrenia as compared to those without the disorder, and this may someday be useful for diagnosis,” she explained.

Blood testing is an important part of schizophrenia care and, combined with medical evaluation, can help support decisions related to diagnosis and treatment.

“Diagnosis of schizophrenia, while it can be challenging when there are other potential causes of psychosis like substance use, is not the hardest part of a psychiatrist’s job,” said Dr. Zick. “It’s much more challenging to effectively treat people’s symptoms while limiting side effects of the medications we use.”

Regular monitoring with blood tests can help psychiatrists protect the mental health of people with schizophrenia without compromising their overall well-being. In the future, some researchers hope to build on the ability of blood tests to support schizophrenia care, including the development of new treatments for this condition.