The Connection Between Cannabis And Psychosis, Explained

As states legalize recreational marijuana, more people are choosing cannabis over alcohol as their go-to way to unwind each day, according to the Associated Press. President Donald Trump announced on Monday, August 11, 2025, that he's considering reclassifying marijuana as a less dangerous drug. Cannabis is currently listed as a Schedule I substance, in the same group as heroin and LSD. Moving it to Schedule III would place it in the same category as ketamine and anabolic steroids. (Read why experts say federal legalization of marijuana can lead to better public health.) 

However, while the Centers for Disease Control and Prevention says that long-term alcohol use raises the risk of cancer, heart disease, and mental health disorders, smoking marijuana may have negative effects on your body, too. For example, a 2018 review in the International Journal of Social Psychiatry analyzed 66 research studies and found that using cannabis doubles the risk of developing psychosis. Researchers believe cannabis's interaction with dopamine in the brain may trigger psychotic symptoms in some people, especially those already vulnerable to psychosis. In some cases, cannabis use may even be a direct cause of psychosis.

In a 2025 study in JAMA Psychiatry, researchers took brain scans of young adults with either cannabis use disorder or recently diagnosed (first-episode) schizophrenia. They focused on midbrain regions, which produce most of the brain's dopamine and send signals involved in reward, motivation, and psychosis. Both cannabis use and schizophrenia were linked to changes in this dopamine system, but people with cannabis use disorder showed significantly stronger activity in the region. Because cannabis appears to act on the same dopamine pathways as schizophrenia, it may contribute to or amplify psychotic symptoms.

(Read about the difference between THC and CBD.)

Of course, this doesn't mean that using marijuana a few times will cause you to develop psychosis. The timing of when you start using cannabis, how often you use it, and how much you consume all matter. According to a 2016 article in Current Psychiatry Reports, heavy cannabis users have up to six times the risk of psychosis. However, early and heavy cannabis users may also be predisposed to psychosis and more likely to engage in other risky behaviors. In other words, cannabis may not directly cause psychosis. Instead, cannabis use and psychosis may share similar risk factors, such as a family history of psychosis, childhood trauma, or social pressures to engage in risky behaviors.