Schizophrenia is a mental health condition that causes psychosis. People with the disorder often struggle with delusions, hallucinations, and other cognitive difficulties. When gone untreated, schizophrenia can have an extremely negative effect on a person’s ability to function at school, work, or other social settings.

Nearly 1% of American adults struggle with schizophrenia and, with that, there’s a lot of discussion as to what causes the illness. While mental health professionals still aren’t entirely sure, we do know genetics plays a major role. ¹

Throughout this article, we’re going to explore what we know about schizophrenia genetics. At the end, we invite you to ask further questions.

What is Schizophrenia?

Schizophrenia is a brain disorder that inhibits a person’s thinking, sense of self, and perceptions. Two of the most common symptoms for this condition are:

• Delusions – false beliefs. For example, someone struggling with schizophrenia may believe they are an important historical figure and playing a role in a major plotline. ²

• Hallucinations – false perceptions. Seeing and hearing things that aren’t really there. Experienced in 70% of schizophrenia patients. ³

Beyond these, schizophrenia symptoms can affect people in 3 different ways. These are as follows: ⁴

Positive Symptoms

Known for their ability to cause psychotic behavior that’s not observed in healthy people. These symptoms are often what make patients lose their sense of reality. They include:

• Delusions
• Hallucinations
• Movement irregularities (agitation)
• Thought irregularities (dysfunctional thinking)

Negative Symptoms

Known for their ability to disassociate individuals from normal emotions and behaviors. They include:

• Decreased expression of emotions through the face or voice
• Difficulty starting and sustaining activities
• Reduced pleasure in day-to-day life
• Reduced speaking

Cognitive Symptoms

Known for their ability to change an individual’s memory along with other areas of thinking. Some people with schizophrenia may experience these symptoms above others. They include:

• Difficulty focusing or paying attention
• Difficulty with “working memory” (ability to use information right after learning it)
• Improper “executive functioning” (ability to comprehend information and use it for decision making)

What Causes Schizophrenia?

As mentioned, mental health professionals still aren’t entirely sure what the causes of schizophrenia are. However, they have identified a few different risk factors that are common among schizophrenia patients: ⁵

• Brain Chemistry – Research has discovered that those who struggle with schizophrenia have an imbalance within their brains. More particularly, neurotransmitters – the cellular communication network responsible for various chemicals, such as dopamine – have shown significant imbalance. While scientists still aren’t sure why this imbalance occurs, it’s believed to have something to do with brain development at birth. ⁶

• Environment – While we aren’t sure what exact environments cause schizophrenia, we are aware that certain psychosocial environments play a major role. For example, it’s been found that those who are born and raised in urban areas are much more likely to develop schizophrenia than those born and raised in suburban or rural areas. Not to mention, environmental problems at birth, such as malnutrition, can also play a major role. ⁷

• Genetics – It’s been found that a person is more likely to develop schizophrenia if someone within their family also struggles with the condition.

It’s important to remember that anyone can develop schizophrenia and the research concerning the causes is limited. With that said, even if you don’t fit into one of the above-mentioned categories, we highly suggest speaking with a mental health professional if you are experiencing schizophrenia symptoms.

Schizophrenia Genetics – What Do We Know?

The truth is, schizophrenia and genetics is extremely complicated. So much so, scientists are still trying to wrap their head around how it all works. It was initially believed that a few common major genes played a role in the effects of schizophrenia. However, tests surrounding these genes always seemed to fall short. ⁸

Like other psychotic disorders, schizophrenia is known as a complex disorder. These conditions are known to cause a number of mutation frequency spectrums within the brain – both common and rare.

Previously it was believed that changes in DNA sequence could hold sole responsibility for individual developing schizophrenia. However, through twin studies, we know that there is much more to it. Some scientists believe it may have something to do with an epigenetic mechanism along with other factors (i.e. environment).

Evidence of Genetics in Schizophrenia

Within the scientific community, there is plenty of evidence that a child of a parent with schizophrenia is at a much higher risk than the rest of the population. ⁹ However, recent studies have found that even when a child is adopted by parents with schizophrenia (no biological relation), they are at just as high a risk of the condition. ¹⁰

There have been around 800 genes tested for their association with schizophrenia – making the condition one of the most studied of mental illnesses. Unfortunately, not a single one of these genes was found to establish the disorder.

With this said, while there is evidence of parent-to-child schizophrenia, it’s not understood exactly what genes play a role in the development of this condition. Not to mention, it seems environmental factors play a much more significant role than scientists initially were led to believe.

Final Word

Schizophrenia is an extremely complex condition and researchers still have a lot to do when it comes to uncovering its underlying causes. While we know genetics plays some role in the development of this disorder, it seems environmental factors may play a larger part than initially imagined.

Still, it’s difficult to tell exactly what causes schizophrenia. With that said, if you experience a multitude of the symptoms mentioned above, we highly suggest seeking out professional help. Schizophrenia can worsen when gone untreated.

Your Questions

Still have questions concerning schizophrenia genetics?

We invite you to ask them in the comments section below. If you have any further knowledge on the topic – whether personal or professional – we’d also like to hear from you.

Reference Sources

¹ National Institute of Mental Health (NIMH): Schizophrenia

² Industrial Psychiatry Journal (Wolters Kluwer — Medknow Publications): Understanding delusions

³ Industrial Psychiatry Journal (Wolters Kluwer — Medknow Publications): Hallucinations: Clinical aspects and management

⁴ MedlinePlus: Schizophrenia

⁵ NeuRA: Risk Factors

⁶ Dialogues in clinical neuroscience: The biology of schizophrenia

⁷ Schizophrenia Bulletin (Oxford University Press): Environment and Schizophrenia: Environmental Factors in Schizophrenia

⁸ The Psychiatric clinics of North America (HHS Public Access): The Role of Genetics in Etiology of Schizophrenia

⁹ Schizophrenia Bulletin (Oxford University Press): Risk of Mental Illness in Offspring of Parents with Schizophrenia, Bipolar Disorder, and Major Depressive Disorder

¹⁰ National Library of Medicine: Adoption studies of schizophrenia