Can Marijuana Trigger Schizophrenia—or Help Treat It?

There’s research to suggest that smoking marijuana (weed), especially at an early age, may increase the risk of schizophrenia and psychosis. But although there may be a connection, it’s not a straightforward cause-and-effect one, and more research is needed. Some parts of marijuana may even help treat schizophrenia, but it’s not clear yet just how effective this is.

Read on to learn more about the connection between schizophrenia and marijuana.

Weed in a jar

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Schizophrenia is a serious mental disorder that impairs cognition, management of emotions, decision-making, and interpersonal relationships. It is a complex, long-term mental illness requiring intensive treatment.

About 0.25% to 0.64% of U.S. adults have schizophrenia. The average age of onset is usually late teens to early 20s for men, and late 20s to early 30s for women, although it may be diagnosed at any age. Although schizophrenia is a serious illness, it is possible to manage and live with the condition.

Symptoms of schizophrenia can include:

  • Delusions
  • Hallucinations
  • Disorganized speech or lack of speech
  • Disorganized or catatonic behavior
  • Inappropriate emotional responses
  • Difficulty communicating and expressing emotions
  • Loss of interest and motivation
  • Difficulty with routine tasks such as personal hygiene

The symptoms of schizophrenia don't all happen at the same time, and a person might experience different symptoms at different times in their life.


Schizophrenia is diagnosed as schizophrenia spectrum disorders, according to the DSM-5.

Smoking Marijuana and Schizophrenia

Many drugs that can be abused can cause psychosis, including marijuana. In addition, multiple studies have found that cannabis use during adolescence results in a higher risk of psychotic disorders in adulthood. In fact, some research has shown that using high-potency marijuana daily before age 15 can make a person five to six times more likely to develop a psychotic disorder than someone who doesn't use marijuana at all.

For young people with clinical psychotic disorders such as schizophrenia, marijuana use is linked to worse disease prognosis, more hospitalizations, and less compliance in taking medications.

More research is needed to understand the relationship between teen use of cannabis and the development of psychotic disorders. Many factors are at play, including an individual’s personal and family health history, how old the person was when they first started using cannabis, and the amount of cannabis used.

Marijuana and the Adolescent Brain

Adolescent brains are still developing and, therefore, may be more susceptible to the effects of drugs, including the tetrahydrocannabinol (THC) found in marijuana. More research is needed, but it's possible that THC exposure in the teenage years could delay the maturation of the prefrontal cortex, which is involved in decision making—thus affecting brain function once the person is older.

Teen Marijuana Use and the Risk of Psychosis

In one study, young teens who smoked marijuana at least five times were twice as likely to develop psychosis over the next decade compared to those who never smoked marijuana.

Cannabis As Treatment

Cannabis is an umbrella term for all the products that come from the plant Cannabis sativa. Some substances in the cannabis plant, known as cannabinoids, have been approved by the Food and Drug Administration (FDA) to treat certain ailments.

Components of Weed

More than 100 cannabinoids have been identified, but the main ones are THC and cannabidiol (CBD). THC causes psychoactive effects, including mind-altering effects, whereas CBD does not cause any psychoactive effects and does not produce a high.

Therapeutic Effects

CBD has been shown to help reduce anxiety in a variety of disorders, including:

Animal studies looking at CBD and schizophrenia showed that CBD improved psychotic symptoms in a manner similar to haloperidol and clozapine but without the catatonia that those drugs often cause. Fewer human studies have been done, but so far, they've shown that CBD is tolerated well, does not worsen mood, and doesn't improve the cognitive impairment often associated with schizophrenia.

THC, meanwhile, has been found to produce psychotic-like symptoms in those with no diagnosed mental illness. These symptoms include hallucinations, delusions, and thought disorders. However, cannabis containing a higher amount of CBD results in fewer subclinical psychotic symptoms, raising the question of whether CBD may moderate the effect of THC.

If you take any medications, check with your healthcare provider before using CBD. It may interfere with certain drugs, including antibiotics, antipsychotics, and antidepressants.


Marijuana use in adolescence, particularly before age 15, has been associated with an increased risk of psychosis. While some components of weed, like CBD, have the potential to be used as a treatment for schizophrenia, more research is needed. In the meantime, marijuana should not be used as a replacement for psychiatric medicine.

A Word From Verywell

If you have schizophrenia, it’s not advised to self-medicate with marijuana. If you already use it, be honest with your healthcare provider. They can evaluate you and develop the best treatment plan for your needs.

If you are worried about your teen’s use of marijuana or your use and the risk of psychosis, talk with your healthcare provider. They can help you reduce or quit marijuana use and discuss your risk of developing a psychotic disorder.


10 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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