Schizophrenia is a chronic psychiatric illness that can affect the way you think, behave, and feel. Researchers are still trying to pinpoint an exact cause.

In the meantime, here’s what we know for sure.

What causes schizophrenia?

Schizophrenia affects less than 1 percent of the U.S. population. Researchers still don’t know the exact cause. A combination of factors can trigger or cause the disorder, including:

  • genetics
  • substance misuse
  • chemical changes in the brain
  • structural changes in the brain
  • pregnancy or birth complications
  • environmental risk factors like childhood trauma
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Genes might be the biggest risk factor for schizophrenia. Having a first degree relative — like a parent or sibling — who has the disorder can increase your risk of developing it.

Several studies on twins have tried to work out an exact risk rate. According to the U.K. National Health Service:

  • If one identical twin has schizophrenia, the other twin’s chance of developing it is 1 in 2.
  • If one fraternal (nonidentical) twin has the disorder, the other twin’s chance is 1 in 8.

To put this in perspective, the general population’s risk rate is 1 in 100. However, the National Institute of Mental Health confirms that genetic info hasn’t yet provided a surefire way to predict who gets schizophrenia.

What is the risk of inheriting schizophrenia?

We still don’t know if schizophrenia has a precise inheritance pattern. But some researchers have tried to come up with a number (get ’em, science).

A 2014 study found that the risk rate is 10 percent if you have a parent or sibling with schizophrenia. And the rate might go up to 40 percent if both parents have the disorder.

Keep in mind that plenty of other factors can increase or reduce your risk of the disorder. So take these numbers with a grain of salt.

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While genetics play a key role in how schizophrenia gets going, other factors can also increase your risk.

Structural changes in the brain

A 2017 research review suggests schizophrenia might have links to gray matter anomalies. (Gray matter makes up the outermost layer of your brain and gets super involved with your central nervous system.)

However, we won’t really know how these structural changes happen in the first place without more studies. Dang.

Chemical changes in the brain

Neurotransmitters are chemical messengers that send signals between brain cells. An imbalance or low levels of these chemicals might contribute to your risk of mental health conditions, including schizophrenia.

There are more than 100 types of neurotransmitters. But these are some of the main players:

Some research has linked glutamate to schizophrenia. A 2014 review also suggested dopamine overactivity might be partly to blame.

But we need more studies to find out what role each neurotransmitter plays in schizophrenia development.

Pregnancy or birth complications

Complications during pregnancy and birth might increase a child’s risk of developing mental health disorders like schizophrenia.

Research has suggested links between schizophrenia and these complications:

Also, people with schizophrenia are more likely to have complications during a pregnancy.

Gender and age

Yes, schizophrenia can develop at any time. But symptoms usually start to show up in men sometime from their late teens to early twenties. In women, schizophrenia tends to rear its head from the late twenties to early thirties.

A 2012 literature review found that schizophrenia rates are slightly higher in men. The same review also noted that men experienced high levels of disorganization and more negative symptoms (such as decreases in speech, movement, and expressiveness).

Meanwhile, women showed higher anxiety and more depressive symptoms.

So, while being male or female might not increase your risk of developing schizophrenia, it might make a difference in how schizophrenia shows itself to you.

Environmental or lifestyle factors can also contribute to schizophrenia. Here are the deets.

Substance use

Certain drugs — like weed, LSD, cocaine, or amphetamines — might trigger schizophrenia symptoms or be a risk factor for folks who already have an increased predisposition to the disorder.

Remember those neurotransmitters we mentioned? Drugs can seriously f*ck with them. Otherwise, why would they make you try to argue with your refrigerator?

There’s also a chance booze increases schizophrenia risk.

(PSA: It works the other way around too — people with schizophrenia are at a higher risk of alcohol or drug abuse compared with the general population.)

Childhood trauma

Environmental risk factors like childhood trauma might up your chances of mental health issues later in life, including schizophrenia. In fact, a 2012 study found that kids who experience extreme trauma might be three times more likely to develop schizophrenia.

Examples of childhood trauma that increase the risk may include:

We still need more research to determine whether childhood trauma can trigger schizophrenia on its own. A combo of trauma, genetics, or other factors might be more likely to cause schizophrenia.

Plus, childhood isn’t the only time trauma comes into play. Extreme stress or trauma at other times of life can also trigger schizophrenia in people who have a genetic predisposition to it.

Schizophrenia isn’t one-size-fits-all. Symptoms can totes vary from person to person. But there are some things to look out for.

Psychotic symptoms

Schizophrenia can change your perceptions of reality, which might result in changes to all your senses.

You may experience delusions (beliefs that aren’t backed up by facts) or hallucinations (seeing or hearing things that aren’t really there).

Cognitive symptoms

Schizophrenia can affect your concentration, attention, and memory.

You might have a harder time:

  • focusing on tasks
  • retaining new info
  • remembering appointments
  • not paying attention to info that doesn’t matter

Negative symptoms

Negative symptoms can affect the way you experience emotions.

Some examples of negative symptoms:

  • a flat vocal tone
  • talking less than usual
  • emotionless facial expressions
  • little to no interest in socializing or activities you previously enjoyed

Behavioral/physical symptoms

Schizophrenia can also cause physical symptoms, including:

  • speech problems
  • loss of muscle coordination
  • uncontrolled body movements or motor behaviors

Alas, there’s not yet a way to prevent schizophrenia. But you can reduce your risk of the condition getting worse. Try to avoid potential triggers like stress and substance misuse, especially if you have a family history of schizophrenia or other known risk factors.

You can also talk with your doc about different medications or alternative treatments that can help you manage your symptoms.

Schizophrenia is a serious mental illness that can greatly impact your day-to-day life. Researchers are still trying to pinpoint an exact cause for the disorder. But we do know the risks go up if you have a close blood relative — like a parent or sibling — who has it.

Other possible risk factors for schizophrenia:

  • childhood trauma
  • substance misuse
  • pregnancy or birth complications
  • chemical or structural changes in the brain

Just remember: Schizophrenia shouldn’t be a source of shame. Give your doc a call if you’re showing signs of the disorder. They can help you find ways to manage your unique symptoms.