Schizophrenia Exams and Diagnostic Tests

Medically Reviewed by Zilpah Sheikh, MD on April 16, 2024
Written by Sarah C.P. Williams, Matt McMillen, Kristin Mitchell
9 min read

A simple finger prick or cheek swab can't show whether someone has schizophrenia. Instead, your doctor will likely talk to you about your symptoms and rule out other disorders before they make a diagnosis. 

There are five core symptoms of schizophrenia:

  1. Delusions. These are false beliefs that you hold onto despite evidence that proves them wrong. For example, you may think someone or some organization, such as the government, is out to get you.
  2. Hallucinations. Most often, these involve seeing or hearing things that are not there but seem real to you. Hallucinations can affect any of your senses, but the most common hallucination is hearing voices.
  3. Disorganized thought or speech. You have trouble making sense when you talk, which indicates your thoughts also may be confused. You may speak in word salads, stringing together nonsense words. You may give unrelated or incomplete answers to questions.
  4. Disorganized movements or behavior. You may move in abnormal ways, such as repeatedly turning around for no reason. Or you may not move at all. Behaviors include things like resisting instructions, becoming agitated without cause, or assuming bizarre or inappropriate postures.
  5. Negative symptoms. This is a reduced or absent ability to function normally. For example, you might stop attending to your personal hygiene, drop contact with other people, and withdraw from your regular activities. You may show little or no emotion.

They may also ask your family about your symptoms and psychiatric history. Other people’s input is important because you might not recognize anything as being wrong.

 Your family members or friends can help by giving the doctor a detailed history and information about things like:

  • Changes in behavior
  • Previous level of social functioning
  • History of mental illness in the family
  • Past medical and psychiatric problems
  • Medications
  • Allergies (to foods and medications)
  • Previous psychiatrists and other doctors

Your doctor may also review a history of your hospitalizations, refer you to a licensed mental health professional (often a psychiatrist) for a psychological evaluation, and conduct certain tests to make a diagnosis. Schizophrenia tests help figure out how severe your symptoms are and point the way to the right treatment. Your doctor may .

To be diagnosed with schizophrenia, you must meet certain criteria established by the American Psychiatric Association’s Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition. These criteria are:

  • You have two or more of the main symptoms of schizophrenia. At least one of them must be delusions, hallucinations, or disorganized thought or speech.
  • You have had these symptoms for a month or more.
  • You have had persistent disturbances for at least 6 months, though they may not be as severe as full-blown symptoms.
  • You have had significant difficulties with at least one major aspect of your daily life since your disturbances began. This means trouble functioning at work, in relationships, or with self-care.
  • You don’t have other disorders that explain your symptoms.

Certain neurological disorders can sometimes cause symptoms that look like schizophrenia, such as:

In order to confirm your symptoms aren't caused by another condition, your doctor will do a physical exam  or other tests, which can include:

Brain imaging tests. These types of tests, such as a CT scan or MRI of your brain, can help rule out issues that affect the brain, such as stroke, tumors, and brain injuries.

Brain activity test. Using an electroencephalogram test, your doctor can measure your brain activity, which can reveal conditions that may explain your symptoms, such as epilepsy.

Generally, lab results and imaging studies are normal in people who have schizophrenia. However, if you have a certain behavior as part of a mental disorder, such as drinking too much water, this might show up as a metabolic problem in your lab results.

Blood tests for schizophrenia

There is no blood test that can diagnose schizophrenia. But blood tests, along with urine tests and cerebrospinal fluid tests, can find chemicals in your system that could be triggering your symptoms. For example, heavy metal toxicity and other poisoning, as well as infection, could be to blame. High or low blood sugar -- revealed by a blood test -- also can cause schizophrenia-like symptoms. Blood tests can help identify other health conditions that can cause similar symptoms. For example, some rare disorders that cause a buildup of fats, or lipids, in your brain cells can eventually produce symptoms that resemble schizophrenia.

Toxicology screen

A toxicology screen can reveal substances in your body that could have led to your psychotic symptoms. These include:

Such symptoms can happen when you’re intoxicated or, and sometimes, during withdrawal. If you’re dealing with substance abuse, your doctor can determine whether your drug use is the only reason for your psychotic symptoms or is simply one factor.

Your doctor also will consider whether your symptoms could be caused by any medications you’re taking or by interactions between certain of those medications. For example, combining corticosteroids and some heart medications can trigger symptoms similar to schizophrenia.

Psychological testing for people with schizophrenia

Once you have been diagnosed, schizophrenia tests can help your doctor determine the severity of your symptoms and guide your treatment.  These tests can include:

  • Cognitive testing
  • Personality testing
  • Open-ended or projective testing such as the Rorschach (inkblot) test

In general, these tests try to gauge how intensely your life is affected by three types of schizophrenia symptoms:

  • Negative
  • Positive
  • Cognitive

Negative symptoms are losses of normal function that cause problems such as flat emotions or expressions. Positive symptoms are feelings or behaviors that are normally not present, like psychotic symptoms that show some kind of break with reality. Cognitive symptoms include effects on your memory and attention.

For some of the tests, your doctor may talk with you for up to an hour and ask you specific questions about your symptoms. Other tests involve a few brief questions.

Your doctor will use the results of your schizophrenia tests to determine whether treatment is helping you, whether the therapy you get now needs to be changed, and whether your condition is getting better or worse.

During this test, you're shown 10 abstract images in the form of symmetrical blots and asked to describe what you see. The test aims to assess your personality as well as how you think, how you function emotionally, and how you perceive the world around you. Developed in 1921 by Swiss psychiatrist Hermann Rorschach, following his work with patients with schizophrenia, the test eventually became widely used for diagnosing mental illness, including schizophrenia. However, its use is controversial. Critics question its scientific value.

The Positive and Negative Syndrome Scale (PANSS) test has a reputation as the "gold standard" for measuring how well your treatment is working. Your doctor likely will use the PANSS test from time to time to check whether treatment has improved in your symptoms.

For the PANSS test, your doctor will interview you for about 40 to 50 minutes. They'll also ask your family members or caregivers about your behavior.

 

The test measures your illness based on 30 different items related to various symptoms. The first seven cover positive symptoms, including:

  • Hallucinations
  • Delusions
  • Hyperactivity
  • Grandiose beliefs, such as beliefs that you’re very famous or have special powers

The next seven items on the PANSS test cover negative symptoms. These include:

  • Reduced facial expressions or expressions of feelings, showing a lack of emotional response
  • Withdrawal from and lack of interest in social activities
  • Difficulty with solving problems using abstract thought
  • Trouble holding a conversation and communicating

The remaining 16 items on the test cover various aspects of your mental health, including:

  • Feelings of anxiety
  • Guilty feelings about real or imagined things you’ve done
  • Depression
  • Signs of physical tension, like sweating and stiffness, that indicate feelings of fear and anxiety
  • Being uncooperative with others, like your health care team and your family, due to distrust, hostility, or other feelings

You’ll receive a score based on your answers and your doctor's observation of your behavior.  Each of the 30 items on the PANSS scale gets ranked from 1 (absent, meaning this symptom is not occurring) to 7 (extreme), giving a total score between 30 and 210.

These two tests analyze the effects of positive and negative symptoms.

SANS stands for Scale for the Assessment of Negative Symptoms. It measures 25 negative symptoms of schizophrenia, including:

  • Lack of facial expressions
  • Social inattentiveness
  • Lack of interests and relationships

The full name of the SAPS test is Scale for the Assessment of Positive Symptoms. It checks 34 positive symptoms, including:

In both scales, each symptom is scored from 0 (none) to 5 (severe).

The Brief Psychiatric Rating Scale (BPRS) is one of the most common tests that psychiatrists use when they want to check how severe someone's schizophrenia is.

The test looks at 18 symptoms or behaviors, such as hostility, disorientation, and hallucination. It ranks each on a scale of 1 (not present) to 7 (extremely severe).

The scores are based on a 20- to 30-minute conversation that your doctor has with you, your family members, or other caregivers.

Like the PANSS test, doctors mostly use the CGI-SCH test when they want to see how well a schizophrenia treatment is working, either for one person or a group of people who are in a clinical trial.

The CGI-SCH measures two things:

  • How severe your schizophrenia is based on your symptoms over the previous 7 days
  • How much your symptoms have changed since your last checkup

Each of the two parts of the test rates the severity of symptoms in five categories:

  • Positive symptoms, like hallucinations and delusions
  • Negative symptoms, like flat emotions and lack of motivation
  • Depressive symptoms, like sadness and hopelessness
  • Cognitive symptoms, like attention and memory problems
  • Overall severity

Each result is measured on a scale of 1 to 7, with 7 being the most severe form of schizophrenia or the greatest increase in schizophrenia symptoms.

While other tests involve a long interview with set questions, the CGI-SCH can be calculated by a psychiatrist in just a few minutes. 

 

Doctors use this test to check you for symptoms of depression that could affect your daily life or might even lead you to have thoughts of suicide.

The scale relies on the answers to just nine questions, including "How would you describe your mood over the last 2 weeks?" and "Have you felt that life wasn't worth living?"

Diagnosing schizophrenia involves plenty of testing, including blood tests and brain scans. These are done to rule out other possible causes of your symptoms. Schizophrenia tests are used after you have been diagnosed. They measure the severity of your disease and how well your treatment works.

Can people with schizophrenia live normal lives? Schizophrenia disrupts significant aspects of life, including your relationships, work, and your ability to care for yourself. However, treatment can help ease your symptoms and allow you to live a fulfilling life with the condition. But some people with schizophrenia don’t respond to treatment or struggle to follow their treatment plan. About 1 in 10 people with schizophrenia die by suicide.

What happens if schizophrenia is left untreated? If you have schizophrenia and aren't treated, you can be at risk to many outcomes, including: 

  • Depression

  • Suicide

  • Obsessive-compulsive disorder or anxiety conditions

  • Disconnect from the world

  • Homelessness

  • Misuse of drugs and alcohol

  • Unemployment or unable to go to school

  • Other health conditions

  • Being vulnerable or easily taken advantageof