In the world of brain disorders, schizophrenia is one of, if not, the most complex. It’s a condition characterized by social withdrawal and a laundry list of symptoms including challenges with cognition or thinking, disorganized behavior, disorganized speech, delusions, and hallucinations.

Affecting about 2.4 million Americans, schizophrenia often first appears during late teens to early 20’s for males, and late 20’s to early 30’s for females. with the age of onset peaking at 20-to-24 years for both genders. Research has shown that it affects men and women about equally.

Unfortunately, while most of those diagnosed for the first time respond well to antipsychotic treatment, fewer than 20 percent maintain recovery over two-to-five years, and most will experience at least one relapse.

While symptoms can differ from person to person, they comprise things like delusions, hallucinations, disorganized speech, agitated and repeated movements, lack of motivation, difficulty understanding information and in decision making, and trouble focusing. It’s a condition that can make it challenging for the person who has it to maintain normal functioning—and for those around them to understand what’s happening.

A Closer Look: This Is Your Brain on Schizophrenia 

There is very little difference between the brains of people with schizophrenia and the brains of people without schizophrenia in terms of standard neuroimaging or EEF findings. Some long-term studies have found a variety of subtle brain differences when comparing groups of people with schizophrenia to others of the same age who don’t have the condition, says psychiatrist Peter Weiden, M.D., Alkermes schizophrenia clinical expert and executive director of medical affairs. Even though brain scans are often used to detect neurologic disease (like stroke, tumors or multiple sclerosis), “these methods are not sensitive enough to diagnose schizophrenia on an individual basis,” Dr. Weiden says. “There are actually no differences in terms of standard neuroimaging, and schizophrenia cannot be diagnosed using neuroimaging.”

(Illustration: Walt Gabriel Brandt)

One of the most noticeable differences are enlarged ventricles (see above), these are cavities in the brain that produce and contain cerebrospinal fluid, which helps reduce the impact from movement and protects the brain from injury. Ventricular size is often used to estimate relative degree of brain volume loss, but there are other factors at play, too. “The brain undergoes a continuous and normal process of pruning over time that can explain some of the changes,” Dr. Weiden said. “Therefore, it is difficult to use ventricular size and brain volume alone as tools for interpretation or diagnosis of schizophrenia.”

The other difference is a reduced volume of gray matter, particularly in the temporal lobe, which processes memories and associates them with sensations of taste, sound, sight, and touch, as well as the frontal lobe, which is important for cognitive functions and control of voluntary movement or activity.

Electric Impulses Are Different

According to research, patients with schizophrenia show more abnormal slow brain wave activity (ASWA) than those who don’t have the syndrome, and particularly in areas in the frontal and central areas of the brain, which are associated with gray matter loss.

This abnormal slow brain activity is the result of dysfunctional neural circuits that can happen because of gray matter loss. “It’s important to understand that any abnormal electrical activity in people with schizophrenia is not the same as seizures but may instead represent problems with connectivity in the brains of people with a schizophrenia diagnosis,”  Dr. Weiden says.

(Illustration: Walt Gabriel Brandt)

There’s A Communication Problem

Due to an impairment in connectivity, certain parts of the brain don’t communicate as well. “There are multiple circuits in the brain that are abnormal in people with schizophrenia,” says Russell Margolis, M.D., clinical director, Johns Hopkins Schizophrenia Center and professor of psychiatry and behavioral sciences.

He explains that the circuits in the brain are all dependent on cells, and if the cells have structural abnormalities, then they aren’t connected the way they should be. “When chemical transmissions between cells are malfunctioning and not sending signals to each other properly, the circuitry doesn’t work well. And when the circuitry doesn’t work well, then you have problems with what the brain does—including thinking and having emotions,” Dr. Margolis says.

“Structural changes in the brain can lead to functional changes,” Dr. Weiden says. “A study from a few years ago found that schizophrenia is a systemic disruption to the brain’s entire communication system.”

And Mixed Messengers

Research also suggests that there is a connection between neurotransmitters—chemical messengers that send information between neurons in the brain—and schizophrenia. The ones that play a role in schizophrenia include, but are not limited to, dopamine, glutamate, and serotonin, Dr. Weiden says. “Of these, problems in dopamine regulation have historically received the most attention when trying to explain how changes in synaptic neurotransmission relate to symptoms of schizophrenia.”

Dopamine is a very basic neurotransmitter that has many functions in normal cognitive and brain functioning. One of the main things it does is regulate motivation and reward. It’s sometimes called the “feel-good” neurotransmitter.

“The dopamine hypothesis of schizophrenia suggests that symptoms associated with schizophrenia can be explained by changes in dopamine function in the brain,” Dr. Weiden says. He explains that excess dopamine in some parts of the brain may lead to psychotic experiences associated with schizophrenia. While too little dopamine in other parts of the brain may explain the lack of motivation and energy that is seen in many people with schizophrenia.

Other evidence suggests that additional neurotransmitters, such as glutamate and serotonin, may also play a role in schizophrenia. “Glutamate is an excitatory neurotransmitter that helps to activate neurons and brain cells. Glutamate and dopamine pathways interact extensively in the brain, including regions that are implicated in schizophrenia,”  Dr. Weiden says.

Evidence also suggests that abnormalities in the activity of serotonin, commonly known as the “happy chemical,” may also play an important role in schizophrenia, Dr. Weiden says. Serotonin seems to have some sort of regulating effect on brain circuits.

How The Schizophrenic Brain Behaves    

People living with schizophrenia simply experience the world differently. And many have a relatively unique set of cognitive impairments, or problems with their intellectual functioning—though they can be subtle and not always used as diagnostic criteria. Here are some of the most common challenges.

Memory Lags

Working memory, which is used to hold information over short periods of time for things like remembering phone numbers or planning the day’s activities, may be diminished, as is the ability to group and store information. People with schizophrenia may also have difficulty learning and retaining verbal information.

Trouble Shifting Between Tasks  

Those affected may have a hard time shifting from one skillset to another. For example, if a grocery store customer asks a cashier with schizophrenia who’s only used to scanning items at checkout to find a replacement product, the cashier could be easily thrown off. “Because of the diminishment in the brain’s network cables, which causes corrupted signals, the person isn’t able to process information properly,” says psychiatrist Frank Chen, chief medical officer, Houston Behavioral Healthcare Hospital.

Making Bad (Judgement) Calls

Patients may have difficulties in executive function, which is sorting through complex information and making good decisions. “They often get stuck on worrying about something that might be theoretically possible but extremely unlikely,” says Thomas Sedlak, M.D., director, Schizophrenia and Psychosis Consult Clinic and assistant professor of psychiatry and behavioral sciences at Johns Hopkins Medicine. “For instance, they might worry that someone they’re speaking with on the phone, whom they know well, such as a relative or friend, is not actually the person, but their evil twin.”

Failing To Predict Consequences

Because of a lack of impulse control, people with schizophrenia often don’t consider the consequences of their actions. This can result in things like petty crimes, such as shoplifting, or aggressive behaviors, Dr. Chen says. Those with schizophrenia may have less insight, experience greater thought disorder, and have poorer control of their aggressive impulses. Impulse control and aggression are thought to be correlated with frontal and temporal brain abnormalities.

Another challenge with not predicting consequences is that people with schizophrenia sometimes overuse alcohol and other substances. This can complicate the agitation and impulsivity.

Feeling Distracted             

Because of thought process abnormalities, some patients experience disorganized thinking  as distractibility. For example, they may start talking about one subject and then shift to a completely different topic even before completing their first thought.

The Positive & The Negative Symptoms

Symptoms of schizophrenia fall into two general categories: positive and negative symptoms. Positive symptoms are mental phenomena like exaggerated ideas, perceptions, or actions that people without schizophrenia might not experience. These include things like hallucinations (hearing voices, seeing things or people that aren’t there, or even feeling things moving on their bodies), and delusions (beliefs that are outlandish, like someone is out to get them or that they’re someone else entirely such as a famous person). They also suffer from disorganized thinking or speech, which manifests as incoherent rambling monologues or “word salads,” Dr. Sedlak says.

Negative symptoms are things that are missing—an absence of mental functioning including behavior, thinking, and perception. These include lack of motivation, energy, emotion, pleasure, personal hygiene, or social withdrawal, Dr. Margolis says.

(Illustration: Walt Gabriel Brandt)

How Schizophrenia Is Made 

Schizophrenia has long been a research puzzle with no exact known cause. “What we do know, is that schizophrenia is caused, or exacerbated, by a complex combination of factors, including genetics, early development, environment, family history, and psychological stressors, as well as neurotransmitter, neurodevelopmental, neurodegenerative, and sensory gating abnormalities, which all may play an important role in disease development,” Dr. Weiden says.

A family history of schizophrenia also increases the chances of developing the disease, and studies have shown that there is a relationship between schizophrenia and more than 100 gene locations, Dr. Weiden says. Your likelihood of developing schizophrenia is more than six times higher if you have a close relative, such as a parent or sibling, with the disorder.

There may also be a developmental issue at play. In normal brain development, brain nerve cells migrate from the deep layer of the brain towards the cortex. “There’s been various hypotheses that in people with schizophrenia, this migration doesn’t occur quite correctly,” Dr. Margolis says.

And then there’s the environmental component. Exposure to viruses or malnutrition before birth, particularly in the first and second trimesters has been shown to increase the risk of schizophrenia. Recent research also suggests a relationship between autoimmune disorders and the development of psychosis. Some studies have also suggested that taking mind-altering drugs during teen years and young adulthood can increase the risk of schizophrenia. A growing body of evidence indicates that frequent smoking of marijuana at a young age increases the risk of psychotic incidents and ongoing psychotic experiences, Dr. Margolis says.

“To help understand the root of schizophrenia, think about the etiology, which is genetics plus environment leading to some form of abnormality in cell structure or chemistry that leads to an abnormality in local circuitry within a small region of the brain, which results in bigger connection problems that causes symptoms,” Dr. Margolis says.

Why Schizophrenia Is So Complicated

There’s still a lot to learn about the illness. One fact that’s been baffling to scientists is the connection between blindness and schizophrenia. No one who was born blind has ever been diagnosed with the disorder. Investigating that connection has led to even more theories. Read more surprising things about schizophrenia here. Then see what’s on the horizon of schizophrenia research, including a certain food that may help ease symptoms.

Article Sources
Last Updated: Aug 17, 2020