According to a new study from the University of Washington (UW), people with psychiatric disorders like schizophrenia, are more susceptible to cannabis health risks, like heart problems, dizziness, and nausea. The study was conducted by researchers at the Addictions, Drug and Alcohol Institute (ADAI) via the Cannabis Education and Research Program (CERP) at the University.
The study also cited a 2025 study conducted in Arizona that found that hospital visits related to cannabis were seven times as likely to entail a psychotic disorder diagnosis when compared to hospital visits unrelated to cannabis.
Researchers at UW surveyed 4,144 cannabis users in the state of Washington over a three-year period. Participants responded by filling out online surveys, allowing researchers to directly collect data from a population base, rather than relying on clinical trials and medical records. Not everyone has access to medical care, the use of surveys provided a deeper look into this particular community of cannabis users.
Nearly 18% of participants with mental health diagnoses experienced psychotic episodes or hallucinations; and 21% experienced nausea and vomiting. Those with no official mental health diagnoses experienced different results. 3% of participants experienced psychotic episodes or hallucinations, and 5% experienced nausea and vomiting.
“We want mental health providers to better understand that addressing cannabis use among their patients who suffer from schizophrenia and other psychotic disorders is really important. Paying attention to cannabis is in the best interest of this population,” said researcher Beatriz Carlini in a recent press release. Carlini is also a research associate professor at ADAI.
Carlini believes that the next step of this research will involve diversifying data by consulting with medical professionals and medical records. Researchers also suggested adding warning labels on cannabis products that speak to mental health risks.
Carlini and her fellow researchers developed an online guide for those in the behavioral health field on how to talk about cannabis and its health impacts to patients.
The guide can be accessed at adai.uw.edu/canntalk.