The Effect of Schizophrenia on the Brain

Schizophrenia is a chronic brain disorder. It affects the brain in particular and less observable ways than other brain conditions like tumors, strokes, or bleeds.

While everyone's brains are different, scientists are able to use imaging to get a general idea of what a normally functioning brain looks like vs. one that is not. There are a number of tests that can be administered to diagnose schizophrenia.

This article will discuss the early symptoms of schizophrenia and the tests and scans that are used to assist its diagnosis.

Early Symptoms of Schizophrenia - Illustration by Theresa Chiechi

Verywell / Theresa Chiechi

Schizophrenia Brain Changes

In some conditions, such as multiple sclerosis, areas of damage are visible on brain scans. This is not the case with schizophrenia. It is not currently possible to diagnose schizophrenia using brain imaging alone.

Instead, researchers look at abnormalities in the brain, which are common among people with schizophrenia and not common in people who do not have schizophrenia.

The brains of people with schizophrenia tend to be different in terms of total tissue volume and activity, specifically lower volumes of gray matter.

These abnormalities are especially noticeable in the temporal and frontal lobes of the brain. Studies also suggest that the hippocampus (a structure in the temporal lobe that influences learning and memory) also presents differently in people with schizophrenia.

Atrophy (loss of brain cells/shrinkage) of the hippocampus is among the most notable changes in the brains of people with schizophrenia.


Neurotransmitters are used by the nervous system to transmit messages between neurons, or from neurons to muscles.

Changes and imbalances in neurotransmitters are believed to play a part in schizophrenia. These include:

  • Dopamine: Dopamine is involved in brain functions such as motor control, reward and reinforcement, and motivation. The brains of people with schizophrenia appear to be sensitive to dopamine in a different way than the brains of people without schizophrenia.
  • Glutamate: People with schizophrenia can exhibit abnormalities in glutamate activity, which influences cognitive functions such as memory and learning.
  • Serotonin: A neurotransmitter involved in regulating mood, sleep, anxiety, sexuality, and appetite, that may also play a role in schizophrenia.

The "dopamine hypothesis" is the belief that schizophrenia is caused by excess dopamine or an extra sensitivity to dopamine. The “revised dopamine hypothesis” proposes there are abnormalities in dopamine balance in different regions in the brain, as well as alterations in other neurotransmitter systems.

Early Symptoms of Schizophrenia 

Because early treatment is thought to be most effective for schizophrenia, researchers are continually looking for ways to detect it before symptoms fully develop.

Hallucinations and delusions are the hallmark symptoms of psychosis and must be present for a diagnosis of schizophrenia.

Although psychotic symptoms such as hallucinations or delusions are the most common aspects that present in schizophrenia, there are several symptoms involved. People with schizophrenia experience:

  • Positive symptoms: The appearance of things that should not be there, like hallucinations, delusions, and thought disorder (unusual thinking or disorganized speech).
  • Negative symptoms: The absence of things that should be there, like loss of motivation, disinterest or lack of enjoyment in daily activities, social withdrawal, difficulty showing emotions, and difficulty functioning normally.
  • Cognitive symptoms: Problems with attention, concentration, and memory.

Assessment of these symptoms is typically how schizophrenia is diagnosed, but the discovery of brain differences in people with schizophrenia could potentially mean an earlier diagnosis and more effective treatment.

While schizophrenia is usually diagnosed in the late teens to early thirties, subtle changes in cognition and social relationships may be noticeable before the actual diagnosis, even during adolescence. Often these early symptoms are apparent years before a person is diagnosed with schizophrenia.

Some of these early symptoms include:

  • A noticeable drop in grades or job performance
  • Trouble thinking clearly
  • Difficulty concentrating
  • Suspiciousness/uneasiness with others
  • A lack of attention to self-care or personal hygiene
  • Spending significantly more time alone
  • Strong, inappropriate emotions or having no feelings at all

Does My Child Have Schizophrenia?

Early signs of schizophrenia can be hard to detect because they often overlap with common adolescent behavior. Moreover, these symptoms in people of any age group do not necessarily mean that a person will develop schizophrenia.

These symptoms can be disruptive though, and they may indicate something worrisome is going on, even if it isn't schizophrenia. If you or your child are experiencing any of these symptoms, you should make an appointment with a healthcare provider.

Risk Factors

Risk factors for schizophrenia include:

  • Genetics: Having a family member with schizophrenia increases the risk of a person developing schizophrenia.
  • Environmental factors: Extreme poverty, stressful surroundings, childhood trauma, and exposure to viruses or nutritional problems before birth are some environmental factors that are associated with an increased risk of schizophrenia.
  • Brain structure: Differences in brain structure, function, and neurotransmitter interactions can contribute to the development of schizophrenia.
  • Drug use: In people who are susceptible, misuse of some drugs, particularly cannabis, cocaine, LSD, or amphetamines, may trigger symptoms of schizophrenia.

Because there are a number of risk factors that can lead to schizophrenia, it may not be possible to pinpoint an exact cause in each case.

Tests and Scans 


There are several commonly used scales that are used in the diagnostic process for schizophrenia.

Some scales used in this determination include:

  • Scale for the Assessment of Positive Symptoms (SAPS)/The Scale for the Assessment of Negative Symptoms (SANS): Using item-point scales, SAPS measures positive symptoms, such as hallucinations, delusions, disordered thinking, etc., while SANS measures negative symptoms, including decreased motivation, difficulty expressing emotions, lack of pleasure, etc.
  • Positive and Negative Symptoms Scale (PANSS): Using an interview format to rate the severity of symptoms, PANSS is used to measure how well treatment is working for an individual. The scale involves 30 scored items.
  • Clinical Global Impression Schizophrenia (CGI-SCH): Developed to examine the effectiveness of antipsychotic treatment in schizophrenia, the CGI-SCH scale is a brief assessment tool used to evaluate positive, negative, depressive, cognitive, and global symptoms. It measures the overall severity of the illness and the degree of change over time.
  • Clinical Assessment Interview for Negative Symptoms (CAINS) and Brief Negative Symptom Scale (BNSS): These are newer scales that both use 13 items to assess negative symptoms. They were developed as updates for older negative-symptom scales.


Brain scans and tests can also be used in the diagnostic process of schizophrenia, all of which are safe and noninvasive. These include:

  • Magnetic resonance imaging (MRI): An MRI uses a strong magnetic field and radio waves to produce two-dimensional or three-dimensional images inside the body and can be used to explore brain structures.
  • Computed tomography scan (CT scan): Using multiple X-ray images, a computer forms a three-dimensional image, allowing body structures to be viewed from multiple angles.
  • Electroencephalogram (EEG): An EEG tests the electrical activity of the brain using electrodes that are (painlessly) attached to the scalp.

The Diagnostic and Statistical Manual of Mental Disorders (DSM-5)

The DSM-5, published by the American Psychiatric Association, is a guide that outlines criteria for the diagnosis of mental illnesses.

Healthcare professionals and mental health experts will refer to the DSM-5 criteria for a diagnosis of schizophrenia.


There is no medical test for schizophrenia, but a healthcare provider may still order blood tests, urine tests, MRIs, and other diagnostic tools when a person presents with symptoms of schizophrenia. This is usually done to rule out other medical conditions or physical factors that could be causing these symptoms.

Some medications and recreational drugs can also cause symptoms of psychosis. A blood test that checks toxicology could determine if these medications are at play.

These tests may also be used to measure aspects of a person's general health, which can help determine the best course of treatment for schizophrenia.

Before and After

If a healthcare professional decides that a medical scan will help in the diagnostic process, then the patient should be prepared for what is required before and after the possible tests.

For an MRI, the patient will lie down on a platform which is then slid into a cylindrical scanner, where they will be asked to hold still to avoid blurry images. It usually takes between 15 to 60 minutes to complete.

MRIs are a generally safe and noninvasive procedure. Because the MRI involves being in a small, enclosed space, sedatives may be offered for people who are claustrophobic or anxious about being in the machine.

Similar to an MRI, for a CT scan, the patient will lie down on a platform which is then slid into a scanner. Unlike an MRI, a CT scanner does not encompass the whole body, but rather is situated over the area being x-rayed. The scanner then spins around the designated area while it takes images.

A CT scan takes between 15 to 30 minutes, but if contrast dye is used, it needs time to circulate before the test begins.

Medical Test Dye

For both MRIs and CT scans, different types of contrast dye may be administered to help the structures be more visible. Side effects and allergic reactions are possible with this dye, so the healthcare provider will ask questions before administering it to minimizes these risks.

Interpreting Results

After an MRI or CT scan is complete, a radiologist will examine the images and interpret the scans. They will then write a report and send it to the healthcare provider who ordered the scans.

It varies by facility, but results are usually made available to the healthcare provider within a few days. The healthcare provider will then explain the results to the patient in an easily understood way.

Brain scans are not currently used to make a positive diagnosis of schizophrenia. If brain scans are ordered it is likely that they are for the purpose of looking for or ruling out other conditions.


A healthcare provider may want to book an appointment to go over the results, regardless of what they are, or they may call with the results.

If the results are inconclusive, your healthcare provider may recommend additional testing. They may also order the tests at certain intervals over time if they are monitoring for changes.

Additional Consultation Needed For Diagnosis

Following any scans or tests, a healthcare professional may make a referral to a mental health expert who has more specialized knowledge on the subject. It is also common for healthcare professionals to speak with the friends and/or family of a person who is showing signs of schizophrenia.

If schizophrenia is diagnosed, then the person with schizophrenia and their support team will work on a treatment plan together.

Frequently Asked Questions 

How does schizophrenia affect the brain? 

Schizophrenia is both a mental health condition and a chronic brain disorder. Abnormalities in both the structures of the brain and brain chemistry have been noted in people with schizophrenia.

Can a brain scan show schizophrenia?

It is not currently possible to determine that a person has schizophrenia simply by looking at a brain scan, but certain changes in the brain that can be observed on a brain scan have been associated with schizophrenia.

What is the role of neurotransmitters in schizophrenia?

It is believed that changes or imbalances of the neurotransmitters dopamine, glutamate, and serotonin play a part in the development of schizophrenia, but more research is needed to fully understand this relationship.

What happens after you get the results from a schizophrenia brain scan?

If brain scans are ordered for a person who is showing schizophrenia symptoms, it is usually to rule out or confirm other conditions that could be causing the symptoms.

Whether the scan shows a different condition or plays a part in confirming a diagnosis of schizophrenia, the healthcare provider will discuss treatment options.

A Word From Verywell

As more research emerges supporting the classification of schizophrenia as a chronic brain condition, in addition to a mental health condition, the opportunities for new and possibly more effective treatments increase.

Schizophrenia treatment is most effective when started early. While currently treatment starts after a diagnosis is made, having a better understanding of differences in the brain means it may be possible to start treatment earlier. Early treatment means hope for better outcomes for people with schizophrenia.

If you or a loved one are experiencing any symptoms suggestive of schizophrenia, see your healthcare provider to discuss diagnosis and treatment options.


If you or a loved one is struggling with schizophrenia, contact the Substance Abuse and Mental Health Services Administration (SAMHSA) National Helpline at 1-800-662-4357 for information on support and treatment facilities in your area.

For more mental health resources, see our National Helpline Database.

8 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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By Heather Jones
Heather M. Jones is a freelance writer with a strong focus on health, parenting, disability, and feminism.