Is schizophrenia genetic? (A brief guide)

Is schizophrenia genetic

In this guide, we will answer the question “Is schizophrenia genetic?” supported by research. Additionally, we will discuss symptoms, risk factors and treatment options. 

Is schizophrenia genetic?

“Is schizophrenia genetic?” is a question researchers have tried to answer for a long time. Through many years of research, they have found that there is actually a significant genetic component that contributes to the development of schizophrenia. Additionally, they have suggested that genetically, schizophrenia and bipolar disorder share the same risk genes.

In addition, there are many relatives of people with schizophrenia that fear that the condition could be inherited. What people ignore is that this is not the only specific cause for developing the illness. Rather, it has been suggested that it is a combination of genetic, psychological and environmental factors.

Studies have found that a small deletion in a region of chromosome 22 called 22q11 has been said to be involved in developing schizophrenia, in some cases and they can even manifest other conditions such as heart disease, immune system problems or cleft palate (NIH).

Is schizophrenia genetic? (A brief guide)

Also, through imaging techniques such as MRI, researchers have suggested that people who have brain abnormalities (neurotransmitters) within the connections between different areas of the brain are at a higher risk of developing schizophrenia. 

Environmental factors can increase the risk of developing schizophrenia and they can even occur before birth. For instance, it is believed that a father who is of advanced age or a mother that was malnourished or had an infection during pregnancy, can increase the risk of their offspring to develop the condition. 

Some life events have also been identified by researchers such as a difficult childhood, the early loss of a parent, poverty, bullying, domestic violence or abuse, is said to contribute also to developing the illness. Individual factors such as drug use/abuse have been found to increase the risk. Let’s take a look in more depth on the risk factors that contribute to increasing the risk of developing schizophrenia. 

But what are the chances of developing schizophrenia? Studies have estimated there is a 50% chance if you have an identical twin that already developed the condition. Additionally, if you have a first degree relative such as a parent or brother/sister with schizophrenia then there is also a high risk of developing the condition. However, if both your parents have it then you can have a 40% chance of getting it. 

According to researchers that studied twins born in Denmark, were able to that if one identical twin had schizophrenia, the other twin was also affected in about a third of cases. “For non-identical twins, who only share on average half of their genes, this was true only in about 7% of cases. Based on these figures, the researchers calculated that 79% of the risk of developing schizophrenia was down to their genes (NHS)”. 

What is schizophrenia?

Schizophrenia is considered a mental illness, classified as a psychotic disorder, that affects someone’s way of thinking, perceiving and their sense of self that becomes more evident during late adolescence or early adulthood, however, there are some rare cases of childhood schizophrenia.

The National Alliance on Mental Illness (NAMI) indicates that “The exact prevalence of schizophrenia is difficult to measure, but estimates range from 0.25% to 0.64% of U.S. adults”, where male tend to be diagnosed in their late teens or the early 20s while women are diagnosed in their late 20s to early 30s. 

Brain chemistry/structure

Scientists have suggested that there are differences in brain chemistry and structure in people with schizophrenia. They have found that the ventricles are larger, parts involved in memory (medial temporal lobes) are smaller and there seem to be fewer connections between neurons. 

Additionally, they have also indicated that there are differences in neurotransmitters, which are in charge of regulating communication among neurons. 

Symptoms of schizophrenia

Symptoms manifested during adolescence can be difficult to differentiate since fist signs such as social withdrawal, low grades, sleeping problems, and irritability tend to be normal during this stage. In young adolescents who develop schizophrenia, the first stage of the disorder is also known as the “prodromal” period. 

However, it is important to get a medical evaluation to obtain a better diagnosis. The diagnosis criteria indicate that symptoms should manifest a significantly reduced functioning for at least a period of 6 months. Symptoms include:

  • Hallucinations: these can present in the form of hearing voices, seeing things or smelling things other people can’t hear, see or smell. They are perceived as very real and it can be quite confusing for relatives, friends or loved ones to witness. 

When having voices, the hallucinations tend to be threatening or critical and they can be perceived as known voices or strange ones. Some others have described the voice as friendly or pleasant, but this happens less frequently. 

Research has shown, with the use of imaging techniques, that areas in the brain related to speech were more active when having hallucinations. 

  • Delusions: These are false beliefs that persist even if the person is confronted with evidence to prove otherwise. People who manifest delusions are said to have problems concentrating, thinking clearly or making decisions. 

They can be associated with hallucinations, for example, if someone is experiencing a hallucination where a voice is describing their actions then they can have the delusion they are being stalked or monitored. 

  • Negative symptoms: it often includes having a blunt affect, losing interest in activities or sustaining relationships, speaking in a dull way, among others. These are often confused as symptoms of clinical depression, tend to appear gradually and get worse over time. 

They can become socially withdrawn and stop caring about personal appearance or hygiene. Also, there is a lack of motivation in normal daily life activities that can cause distress in the family or a partner. 

  • Disorganized thought and behavior: people with schizophrenia usually have memory problems, completing tasks or organizing their thoughts. They will usually have a hard time concentrating on one idea and will keep drifting, some people may even have trouble reading the newspaper or watching TV. 

Additionally, their behavior can become unpredictable and disorganized They may even feel their bodies or minds are being controlled by someone else.  

It is common for people with schizophrenia to have a lack of insight about the illness, making any attempts for treatment quite challenging. 

Is schizophrenia genetic? (A brief guide)

Causes of schizophrenia

Besides genetic factors, as we have discussed so far, there are other potential causes such as:

  • Environmental factors: these can include being exposed to viruses or toxins, malnutrition before birth, stressful life events such as losing someone close or being abused.
  • Brain chemistry: imbalances in the neurochemistry of the brain, such as neurotransmitters dopamine and glutamate can increase the risk of developing schizophrenia. They are known to play a crucial role in allowing neurons to communicate between them. 
  • Substance abuse: the use of psychoactive or psychotropic drugs during adolescence or as a young adult can contribute to developing the disease. Smoking Marijuana has been evidenced to increase the presentation of psychotic episodes and the risk of psychotic experiences. 
  • Frequent immune system activation: schizophrenia has been linked to inflammation or autoimmune diseases. 
Is schizophrenia genetic? (A brief guide)

How is schizophrenia diagnosed?

The diagnosis of schizophrenia can be challenging since it can get confused with other mental or medical conditions. Additionally, there is no single physical or lab test that can help with the diagnosis of schizophrenia, instead, observation of the symptoms over a course of 6 months or the use of imaging techniques and a complete medical assessment, can help to rule out other possible medical conditions and ensure a correct diagnosis. 

According to the latest version of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5), to get the diagnose of schizophrenia the following symptoms must be present during at least 1 month (at least one must be delusions, hallucinations or disorganized speech) and need to reduce significantly their quality of life:

  • Delusions
  • Hallucinations
  • Disorganized speech
  • Grossly disorganized or catatonic behavior
  • Negative symptoms such as blunting of affect, poverty of speech and thought, apathy or loss of motivation.

Treatment

There is no cure for schizophrenia, however, the symptoms can be treated improving the quality of life of the person and their family:

  • Antipsychotic medication: they are meant to influence the brain chemicals that regulate thought patterns and emotions. However, it can be difficult to determine who will respond to treatment since it varies from one person to the other. Doctors may attempt to try different medications and see how the person responds to them.

This type of treatment won’t provide immediate results, so it will take a while before you see a significant improvement. 

  • Psychotherapy: the most commonly used therapy is cognitive behavioral therapy and assertive community treatment and supportive therapy, where relatives and loved ones can be involved to support the person in their treatment. 
Is schizophrenia genetic? (A brief guide)

Why is this blog post “Is schizophrenia genetic” important?

As we have discussed, schizophrenia does have a genetic component and can predispose someone but it is not enough for the condition to develop. There are other risk factors such as environmental or individual traits that when combined with genetic predisposition increases the risk of manifesting the disorder. 

It is important to be aware that symptoms can be easily confused with other medical or mental health conditions so a complete and thorough assessment is necessary to provide an accurate diagnosis and get appropriate treatment as early as possible.

Please feel free to comment in the comments section below!

Frequently Asked Questions (FAQs) about “Is schizophrenia genetic?”

Does schizophrenia run in families?

Even though research suggests schizophrenia runs in families, people with relatives or even siblings with schizophrenia don’t always develop the disorder. There is a clear genetic component but other environmental and individual traits have been identified as factors that increase the chance of developing the condition. 

Can schizophrenia be inherited and passed down from parents?

Genetics influence the development of schizophrenia but it isn’t directly inherited or passed down from parents. There is a mix of other factors that contribute to developing the disease, even if people with first-degree relatives are at a higher risk they may not necessarily develop this mental illness. 

Are you born with schizophrenia or do you develop it?

As discussed, schizophrenia has a genetic component but no single gene has been identified as being responsible for developing the condition. It is believed that the combination of genes are the ones responsible for making people vulnerable or at a higher risk. 

Is schizophrenia passed from the mother or father?

Parents share half of their children’s genes, however, it is said that there is only a 6% chance that the offspring of a schizophrenic parent will actually develop schizophrenia. Even more so, studies in identical twins have found that even if one of the twins develops schizophrenia, the other twin only has a 48% chance of developing the disorder.

Is there a test for schizophrenia?

There are no specific tests for schizophrenia, however, a mental health professional or a doctor can use diagnostic criteria from the DSM or tests such as MRI or CT scans and blood tests to rule out other conditions. 

Recommended reading

References

Is Schizophrenia a Genetic Disorder?

Healthline

NAMI

WebMD

NHS

NHS: Schizophrenia Symptoms

NIH: US National Library of Medicine

Is schizophrenia genetic? (A brief guide)

Juanita Agboola

Juanita Agboola is the editor in chief of HFNE and an expert in mental health online. She has been writing about online behaviour, mental health and psychology issues since 2012. All Guides are reviewed by our editorial team which constitutes various clinical psychologists, PhD and PsyD colleagues.