Key takeaways
- Genetics plays a role in the development of schizophrenia. For example, if an identical twin has the condition, there is a 1 in 2 chance of the other twin developing it.
- Chemical changes in the brain, particularly involving neurotransmitters such as dopamine and glutamate, may have links with the development of schizophrenia.
- Complications during pregnancy or birth may increase the risk of schizophrenia. These include preterm labor, lack of oxygen, low birth weight, and more.
A person living with schizophrenia disorder may experience periods in which they seem to have lost touch with reality. They may experience the world differently from the people around them.
Researchers have some ideas as to who is at greatest risk of developing the condition and potential risk factors. Understanding the possible causes and risk factors for schizophrenia can help clarify who might be at risk.
Genetics
One of the most significant risk factors for schizophrenia may be genes. This disorder tends to run in families. If you have a parent, sibling, or another close relative with the condition, you may have a higher likelihood of developing it, too.
However, researchers don’t believe a single gene is responsible for this disorder. Instead, they suspect a combination of genes can make someone more susceptible.
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Researchers found that if one identical twin sibling has schizophrenia, the other has a 1 in 2 chance of developing it. This remains true even if the twins are raised separately.
If a twin is nonidentical (fraternal) and has been diagnosed with schizophrenia, the other twin has a 1 in 8 chance of developing it. In contrast, the risk for disease in the general population is 1 in 100.
Structural changes in the brain
If you’ve been diagnosed with schizophrenia, you may have subtle physical differences in your brain. But these changes aren’t seen in everyone with this disorder.
They may also occur in people who don’t have a diagnosed mental health disorder.
Still, the findings suggest that even minor differences in brain structure may play a role in this psychiatric disorder. Researchers, however, have not been able to determine whether schizophrenia is a progressive brain disorder. Nor have they been able to determine when the structural changes occur and even how they develop over time.
Chemical changes in the brain
A series of complex interrelated chemicals in the brain, called neurotransmitters, are responsible for sending signals between brain cells.
Imbalances of these chemicals are believed to play a role in the development of schizophrenia and other mental health conditions.
Dopamine, in particular, seems to play a role in the development of schizophrenia. Researchers have found evidence that dopamine causes an overstimulation of the brain in people with schizophrenia. It may account for some of the symptoms of the condition. There’s a link, but the cause-and-effect relationship remains unknown.
Glutamate is another chemical that’s been linked to schizophrenia. Evidence has pointed toward its involvement. However, there are several limitations to this research.
Pregnancy or birth-related factors
Complications before and during birth may increase the likelihood that a person will develop mental health disorders, including schizophrenia.
These complications include:
- infection during pregnancy
- preterm labor
- delivery complications, including lack of oxygen during delivery (asphyxia)
- low birth weight
- maternal obesity in pregnancy
- certain maternal health conditions, like diabetes
- certain pregnancy-related health issues, like preeclampsia
- season of birth
Because of the ethics involved in studying pregnant people, many of the studies that have looked at the connection between prenatal complications and schizophrenia have been on animals.
People living with schizophrenia are also at an increased risk for complications during pregnancy.
It’s unclear if their children are at an increased likelihood of developing the condition because of genetics, pregnancy complications, or a combination of the two.
Childhood trauma
Childhood trauma is also thought to be a contributing factor in developing schizophrenia. Some people with schizophrenia experience hallucinations related to abuse or neglect they experienced as children.
People are also more likely to develop schizophrenia if they experienced the death or permanent separation of one or both parents as children.
This kind of trauma is tied to a variety of other adverse early experiences, so it’s still unclear if this trauma is a cause of schizophrenia or just associated with the condition.
Triggers are other factors that may also play a role in the development of schizophrenia in those who are at risk. A couple of triggers are thought to play a role.
Stress
While stress doesn’t cause schizophrenia, it can trigger an episode of psychosis. Researchers have found that stress during critical periods of development may be particularly impactful, increasing a person’s susceptibility to psychosis.
Previous drug use
Using cannabis, cocaine, LSD, amphetamines, or similar drugs doesn’t cause schizophrenia. However, a 2023 Danish report found that heavy cannabis use is linked to schizophrenia, especially among young men.
Because researchers don’t completely understand what causes schizophrenia, there’s no sure way to prevent it.
However, if you’ve been diagnosed with this disorder, following your treatment plan can reduce the likelihood of relapse or worsening symptoms.
Likewise, if you know that you’re at an increased risk for the disorder — such as by a genetic link — you can take steps to avoid known triggers like stress and drug use.
Symptoms of schizophrenia usually first appear between the ages of
Symptoms fall into four categories:
- positive
- negative
- cognitive
- disorganization, or catatonic behaviors
Some of these symptoms are always present and occur even during periods of low disorder activity. Other symptoms only show up when there’s a relapse or increased activity.
Positive
Positive symptoms may be a sign that you’re losing touch with reality:
- hallucinations or hearing voices
- delusions
- thought disorders or dysfunctional ways of thinking
This category of symptoms is associated with significant difficulties in daily functioning.
Negative
Negative symptoms interrupt normal behaviors. Examples include:
- lack of motivation
- reduced expressions of emotions (“flat affect”)
- loss of pleasure in everyday activities
- difficulty concentrating
Cognitive
Cognitive symptoms affect memory, decision making, and critical-thinking skills. They include:
- trouble focusing
- poor “executive” decision making
- problems with using or recalling information immediately after learning it
This category of symptoms is
Disorganization
Disorganization symptoms are both mental and physical. They show a lack of coordination.
Examples include:
- motor behaviors, such as uncontrolled body movements
- speech difficulties
- memory recollection problems
- loss of muscle coordination, or being clumsy and uncoordinated
- disorganized thought process
If you believe you or a loved one is showing signs of schizophrenia, it’s important to seek immediate treatment.
Keep these steps in mind as you seek help or encourage someone else to find help:
- Remember that schizophrenia is a biological illness: Treating it is as important as treating any other illness.
- Find a support system: Find a network you can rely on or help your loved one find one they can tap into for guidance. This includes friends, family, colleagues, and healthcare professionals.
- Check for support groups in your community: Your local hospital may host one, or they can help connect you to one.
- Encourage continuing treatment: Therapy and medications help people lead productive and rewarding lives. You should encourage a loved one to continue treatment plans.
There’s no cure for schizophrenia. It requires lifelong treatment. However, treatments focus on easing and eliminating symptoms, which can help you manage the condition.
Management
Typical treatments for schizophrenia include:
- Antipsychotic medications: These medications affect brain chemistry. They help decrease symptoms by affecting the level of chemicals believed to be involved in the disorder.
- Psychosocial therapy: You can learn coping skills to help you manage some of the challenges this disorder causes. These skills can help to complete school, hold a job, and maintain quality of life.
- Coordinated specialty care: This approach to treatment combines medication and psychosocial therapy. It also adds family integration, education, and employment counseling. This type of care aims to reduce symptoms, manage periods of high activity, and improve quality of life.
Finding a healthcare professional you trust is an important first step toward managing this condition. You’ll likely need a combination of treatments to manage this complex condition.
Your healthcare professional may also need to alter your treatment plan at different times in your life.
Schizophrenia is a lifelong psychiatric condition. Researchers don’t know exactly what causes it. A combination of factors likely plays a role.
Understanding the possible causes and risk factors for schizophrenia can help clarify who might be at risk and how to help them.