Laboratory tests can help rule out medical conditions that resemble schizophrenia and provide further insight into the condition.

Schizophrenia is a complex mental health disorder that affects millions of people worldwide. The specific symptoms can differ depending on the person, but the diagnostic criteria are the same.

If you or a loved one is experiencing symptoms of schizophrenia, know that establishing the diagnosis can be challenging, but help is available. A qualified healthcare professional can help you better understand your symptoms.

While there aren’t any tests that can make a schizophrenia diagnosis, a laboratory test can help rule out other medical conditions that may be causing symptoms resembling schizophrenia.

Complete blood count (CBC)

A CBC may be ordered to rule out other medical conditions that can cause symptoms similar to those seen in schizophrenia.

A CBC measures levels of different blood components, including:

  • red and white blood cells
  • platelets
  • hemoglobin and hematocrit

Comprehensive metabolic panel (CMP)

A CMP is a blood test that measures the levels of different chemicals in your blood. Like a CBC, its purpose is to evaluate your overall health and exclude other medical conditions that can cause psychiatric symptoms.

A CMP includes the following measurements:

  • glucose
  • electrolytes
  • liver enzymes
  • kidney function
  • protein/albumin

Urine and drug screening tests

There are some drugs that can create symptoms such as hallucinations and paranoia, which resemble positive schizophrenia symptoms (such as hallucinations or delusions). The purpose of urine and drug screening tests is to detect the presence of these drugs.

Urine tests involve collecting a sample of your urine for analysis, and other drug screening tests typically involve collecting a blood sample. Both samples are analyzed for the amount of the specific substance being tested for in your blood or urine.

Brain MRI

Magnetic resonance imaging (MRI) is an imaging study that can be ordered when a tumor is suspected. A tumor may impact the brain and cause symptoms seen in schizophrenia.

An MRI also produces detailed images of your brain to look for structural abnormalities, which can sometimes be observed in schizophrenia.

Brain CT

Computed tomography (CT) scans may be ordered for a similar purpose as brain MRIs. However, CT scans are often faster than MRIs and can also provide imaging of the bones as well as the soft tissues.

CT scans are sometimes preferred over MRIs if you have a metallic implant or if a rapid diagnosis is needed. The major downside to CT scans is that you’d be exposed to high levels of harmful radiation.

PET Scan

Positron emission tomography (PET) scans use a radioactive tracer and a special camera to create images of your brain’s activity. The tracer is injected into your blood and then releases measurable radioactive signals (positrons).

A PET scan can provide information about the specific function of certain brain regions. Whereas an MRI and CT scan can identify structural changes, a PET scan can identify functional changes.


An electroencephalogram (EEG) evaluates the electrical activity in your brain. Similar to PET scans, EEGs seek to identify differences in brain activity that may be contributing to schizophrenia symptoms.

Magnetoencephalography (MEG) is similar to an EEG but measures magnetic field activity in your brain rather than electrical activity. MEG is thought to be more precise than EEG.

A clinical evaluation is often the first step in establishing a schizophrenia diagnosis. This means you’ll speak with a mental health professional and answer a number of questions about your medical history and symptoms. Labs and imaging studies would also be ordered at this step.

To make a diagnosis, a mental health professional will determine whether or not your symptoms fit into the diagnostic criteria for schizophrenia. According to the Diagnostic and Statistical Manual of Mental Disorders, 5th edition, text revision, a diagnosis of schizophrenia occurs when the following criteria are met:

  • presence of at least one positive symptom
  • presence of at least one negative symptom
  • other medical conditions have been excluded
  • symptoms interfere with work or social life
  • symptoms are experienced for most days of at least 1 month over a 6 month time period

There are several other disorders that must be ruled out before schizophrenia can be diagnosed.

Other mood disorders, such as bipolar disorder, are especially important to rule out because they can sometimes be confused with schizophrenia and are difficult to tell apart.

Personality disorders must also be ruled out due to their strong similarities. These may include conditions such as schizotypal personality disorder and borderline personality disorder. Similar symptoms can include disturbances in self-image or strong feelings of isolation, according to a 2018 study.

Certain neurological conditions can also be mistaken for schizophrenia. For example, brain tumors and epilepsy can sometimes lead to delusions and hallucinations.

Substance use disorder (SUD) may also resemble schizophrenia. The following substances can create symptoms that mimic schizophrenia symptoms:

  • alcohol
  • cannabis
  • hallucinogens, such as LSD
  • stimulants, such as cocaine and amphetamines

While there’s no single test that can diagnose schizophrenia, laboratory tests can be useful in ruling out other medical conditions. Imaging studies of your brain can similarly provide helpful information about its structure and function, although they aren’t used to establish a diagnosis.

A diagnosis of schizophrenia requires a comprehensive evaluation by a healthcare professional, which takes into account your symptoms and medical history, among other factors. The goal of this evaluation is to rule out other potential causes of the symptoms and arrive at an accurate diagnosis of schizophrenia.

If you or someone you know is experiencing symptoms of schizophrenia, rest assured that there are many ways healthcare professionals can help get to the bottom of what’s going on.