Even as the public’s understanding of mental illness continues to evolve, some conditions are still commonly misunderstood and misrepresented. Fears and assumptions about a person’s behaviour can lead to oversimplifications, stereotypes, and sometimes outright incorrect information.

That is often the case when it comes to schizophrenia, a mental disorder that can cause disruptions in thought processes as well as delusions that aren’t based in reality.

Even though schizophrenia is relatively rare, it’s one of the top 15 leading causes of disability worldwide. It’s estimated that the average potential life lost for people with the disorder is 28.5 years, according to the National Institute of Mental Health.

Here we cover seven important myths and facts about schizophrenia to help you separate the truth from fiction.

1. FACT: A Person’s Genes Can Increase the Risk of Developing Schizophrenia

“We know there is an underlying genetic component to schizophrenia,” says Jacob S. Ballon, MD, a clinical professor of psychiatry and behavioural sciences and the co-director of the INSPIRE Clinic, which provides interdisciplinary care for people experiencing psychosis, at Stanford University in Stanford, California.

A number called a polygenic risk score can help determine what a person’s risk for different conditions may be, taking into account multiple genetic variants. “It’s not just one gene that causes the illness – it’s many, many genes that together are complicated and beyond our level of understanding,” Dr. Ballon says.

By using the current statistical model for schizophrenia that takes into account all known factors that relate to someone developing the condition, experts estimate that the genetic component constitutes about 10 percent of the risk, says Ballon.

2. MYTH: People With Schizophrenia Have Multiple Personalities

This myth certainly is persistent, but it’s hard to say where it started, says Ballon. “One of the best explanations I’ve heard comes from breaking down the word schizophrenia. Etymologically it comes from the word ‘schizo’ meaning split and ‘phrenia’ meaning mind,” he says.

Putting those two meanings together might lead people to draw the wrong conclusion and think that someone with schizophrenia has two or more personalities.

“When a person displays multiple personalities, it’s called dissociative identity disorder (DID). It’s a different disorder and has different risk factors,” says Ballon, adding that DID is more closely related to the experience of trauma.

3. FACT: Marijuana Use Is Associated With an Increased Risk of Schizophrenia

Marijuana use is associated with an increased risk of psychosis – meaning loss of contact with reality – as well as an increased risk of schizophrenia, says Ballon.

Tetrahydrocannabinol, or THC – the component of cannabis that’s most responsible for the psychoactive effects of marijuana – is likely at the root of these risks, according to a systematic review published in 2020 in Cureus.

As more potent strains of marijuana enter a community, the rate of psychosis increases, says Ballon, referencing work by Robin Murray and colleagues published in World Psychiatry in 2016.

All the things that we learned about marijuana a generation ago are probably not accurate anymore because the marijuana is so much stronger and used so much more frequently by the average user, he says.

4. MYTH: Having Schizophrenia Means You Will Be Violent

While people with schizophrenia do have a higher risk of violence than the general population, it’s still relatively rare. The risk of committing violence is less than 1 in 4 among men with schizophrenia, and less than 1 in 20 among women with the condition, according to a systematic review of 24 studies published in 2022 in JAMA Psychiatry.

What’s more, most acts of violence often have nothing to do with schizophrenia itself. Rather, a number of other risk factors affect the odds of violence among people with the condition. For instance, substance abuse appears to be strongly linked with violence among people with schizophrenia, according to a review published in 2018 in the Nordic Journal of Psychiatry.

5. FACT: People With Schizophrenia Have a Higher Risk of Suicide

Having schizophrenia is a risk factor for suicide, says Ballon. It’s estimated that about 10 percent of people with schizophrenia die by suicide, according to a review article published in 2019 in Medicina.

Suicide attempts for people with the condition are even higher. The lifetime prevalence of suicide attempts among people with schizophrenia is 39.2 percent, compared with 2.8 percent in the general population, according to Canadian research published in 2016 in Schizophrenia Research and Treatment.

These attempts can be at any number of points in the course of the illness, says Ballon. “It can be when a person may be having symptoms and hearing voices telling them to kill themselves. It could be shortly after a person is recovering from many symptoms – they may look at what happened in a different way and be worried about their future and more likely to want to harm themselves at that point,” says Ballon.

That can be especially true when people are taking on certain internalised stigmas about what they’re likely to achieve when they have a mental illness, says Ballon. “They may feel they’re not going to be able to have the life they were expecting; and therefore may be at greater risk at that point,” he says.

“Further, there’s an overlap between schizophrenia and depression, and that in and of itself may also increase the risk of people wanting to harm themselves,” he adds. Depression is another known risk factor for suicide, according to the Centers for Disease Control and Prevention.

6. FACT: It’s Common for People With Schizophrenia to Have Delusions That Aren’t Based in Reality

Delusions ie. steadfast false beliefs that don’t align with reality, are a very common symptom in people with schizophrenia or related psychotic disorders, according to the Mayo Clinic.

A person with the condition might experience various types of delusions. “There are persecutory delusions, where a person feels watched or followed,” says Ballon. “They might feel like the government is after them or that they have special information that somebody else might need to obtain from them. That can make a person feel very worried or scared.”

Another type is somatic delusions, where a person might feel contaminated, says Ballon. “The person might feel like something is wrong with their internal organs or maybe they think they have an illness that there isn’t any reason to believe they have,” he says.

Someone with schizophrenia may also experience delusions of grandeur, where they believe they have special abilities or powers, says Ballon. For instance, he adds, they might believe that they are the president of the United States or Jesus Christ, or that they control the weather.

“The hard part is that you can’t really talk somebody out of a delusion, so it can be very challenging to work with,” says Ballon.

7. MYTH: There Isn’t an Effective Way to Treat Schizophrenia

Although there’s no cure for schizophrenia, several evidence-based treatments can help people manage symptoms and help people live reasonably well with the condition.

The most common treatments for schizophrenia are medication – most commonly antipsychotic medications, and interventions such as individual therapy, family therapy, social skills training, and supported employment, according to the Mayo Clinic.

Your doctor will help you find a treatment that works best for you. Ballon says he tries to include the person with schizophrenia and the family in the decision-making process when it comes to treatment, but how well people respond to treatment varies.

Additional reporting by Christina Vogt.