Psychotic disorders, such as Schizophrenia, disrupt a person’s ability to differentiate between reality and inner thoughts and feelings. They often manifest with hallucinations, loss of motivation, trouble thinking clearly, strange or lack of feelings, trouble with speech and communication, and sudden drop in grades or job performance among many other behavioral signs. These disorders affect between 2.3% to 3.5% of the population and tend to emerge during adolescence or early adulthood and are associated with adverse outcomes such as suicide and an average reduced life expectancy between 10 to 20 years.

Research studies have long suggested a potential link between marijuana use and psychotic disorders. A recent study conducted by McDonald et al., uncovered that these associations not only exist but are much stronger than anticipated. The study featured in the journal Psychological Medicine, examined hospitalizations, Emergency Department (ED) visits, and outpatient visits, drawing from a sample exceeding 11,000 adolescents. They evaluated different ages finding a stronger association in the adolescent years than any other stage. Their findings revealed that 5 out of every 6 teenagers who sought treatment for a psychotic episode had previously used marijuana, marking an 11-fold increase in the likelihood of psychotic episodes compared to those who refrain from the use of the drug. This was in line with the neurodevelopmental theory, which recognizes adolescence as a crucial stage when marijuana presents a greater risk. While the study cannot point to a cause-effect relationship, a strong association between suffering a psychotic break following the use of marijuana was observed.

In summary, psychotic disorders like schizophrenia profoundly disrupt individuals’ perception of reality, often emerging during adolescence or early adulthood with severe consequences. Recent research indicates a strong association between marijuana use, especially among adolescents, and an increased risk of psychotic episodes. McDonald et al.’s study underscores this link, revealing an alarming prevalence of marijuana use among adolescents seeking treatment for psychosis. The evolving perceptions of marijuana use, where it is increasingly seen as less dangerous, coupled with the still-developing adolescent brain, contribute to risky behaviors such as experimenting with drugs. This is particularly concerning as marijuana can have a stronger impact on maturing brains compared to adults. These findings emphasize the urgent need for heightened awareness of the potential risks of marijuana use, particularly during crucial developmental stages.


  1. Mundell, E. (2024, May 22). Teen Cannabis Users’ Risk for Psychosis May Be Stronger Than Thought: Study. US News.
  2. McDonald AJ, Kurdyak P, Rehm J, Roerecke M, Bondy SJ. Age-dependent association of cannabis use with risk of psychotic disorder. Psychological Medicine. Published online 2024:1-11. doi:10.1017/S0033291724000990
  3. National Institute of Mental Health. (2024). Understanding Psychosis.