Cannabis Use Rises Among Individuals with Psychosis Following State Legalization, Raising Concerns for mental health Professionals
BOSTON – A new study reveals a meaningful increase in cannabis use among adults with a history of psychosis following the legalization of recreational marijuana, sparking concern among psychiatrists and researchers about potential worsening of mental health outcomes. The research,published in JAMA Psychiatry,analyzed data from 1,856 adults with a lifetime history of psychosis through the Population assessment of Tobacco and Health Study (PATH),a collaboration between the Food and drug Management and the National Institutes of Health.
The study found cannabis use increased by nearly 10% five years after states legalized recreational marijuana use. While the majority of cannabis users do not develop psychosis, experts emphasize a well-established link between the drug and an increased risk of developing the condition earlier in life and experiencing a more severe course.
“Users have more severe hallucinations,delusions,worse disability,lower medication adherence,more admissions,[and] need higher doses,” explained Matthew Large,a psychiatrist and professor at the University of New South Wales in Sydney,Australia.
Researchers noted they were unable to determine the potency of the cannabis used by participants, or whether increased use directly correlated with declining mental health. However, the study highlights a concerning trend, especially as the commercialization of cannabis in retail shops appears to be driving the increase in use, rather than simply more frequent consumption. The data showed that while use increased, the frequency of use among those with psychosis did not.
The rapid proliferation of legal cannabis has outpaced regulatory efforts, with only two states currently requiring warnings about the link between high-potency cannabis products and psychosis, according to a 2024 study. Experts suggest potency caps and health warnings could help mitigate potential harms.
The study’s authors acknowledge limitations, including an overrepresentation of women in the sample and reliance on self-reported psychosis diagnoses. Lead researcher Dr. Hyatt explained the study was motivated by a desire to understand the impact of legalization on a population already facing significant challenges in accessing adequate mental healthcare.
“There is a somewhat randomized natural experiment happening across states with states having very diffrent laws,” hyatt said.he also expressed a need for further research, particularly focusing on the rise of high-potency cannabis products, stating, “I would love, going forward, for other datasets [than the PATH] to study this.”
The biological mechanisms linking cannabis use and psychosis remain unclear, prompting ongoing examination into the complex relationship between the drug and mental health.
