A recent study highlights a significant rise in cannabis consumption among individuals with psychosis in states that have enacted legalization measures.
Health experts caution that this trend, when paired with the availability of higher potency cannabis, may exacerbate pre-existing mental health conditions and pose risks for those predisposed to psychosis.
According to Andrew Hyatt, a psychiatrist associated with the study, THC—the principal psychoactive substance in cannabis—has a known impact in triggering and worsening symptoms of psychosis.
“Consuming it in highly concentrated forms is analogous to having one Bud Light compared to taking several shots of tequila,” Hyatt stated.
The findings from the JAMA Psychiatry report examined data from 1,856 adults who had experienced psychosis at some point in their lives, drawn from the Population Assessment of Tobacco and Health Study, which is a collaboration involving the Food and Drug Administration and the National Institutes of Health. The study discovered that cannabis usage surged almost 10% in the five years following the legalization of recreational marijuana.
However, the authors could not derive information on the typical potency of the cannabis being consumed nor establish whether the increase in usage correlated with deteriorating mental health status. Despite the fact that most cannabis users do not develop psychosis, various studies suggest a relationship between cannabis use and an elevated risk of early-onset psychosis that tends to result in poorer prognoses, as noted by Matthew Large, a psychiatrist and professor at the University of New South Wales, Sydney, Australia.
“Users experience more intense hallucinations and delusions, increased disability, lower adherence to treatment plans, more hospital admissions, and often require higher medication doses,” large elaborated.
Despite the potential risks, the rapid expansion of legal cannabis appears to have outpaced any regulatory efforts. A study conducted in 2024 found that only two states mandate warnings regarding the association between high-potency cannabis products and psychosis. Experts suggest that implementing potency caps and health warnings could help alleviate some of these risks.
The study indicated that while cannabis use rose post-legalization, the most significant increase occurred with the commercialization of cannabis products through retail outlets. Notably, although more individuals with psychosis are turning to cannabis, they are not using it more frequently through smoking, vaping, or ingestion.
There are, however, limitations in the data. The sample had a disproportionate number of women, and participants self-reported their psychosis diagnoses, leaving a gap regarding their treatment history relative to cannabis use.
The exact biological mechanisms connecting cannabis use with psychosis remain elusive. Hyatt expressed that the scientific ambiguity partly motivated him and his colleagues to explore how drug legalization has influenced a population that psychiatrists and psychologists often find challenging to support adequately.
“There’s a sort of natural experiment occurring across different states that have enacted varying laws,” he explained, adding that “we currently lack data on the proliferation of high-potency products, which have rapidly become available in recent years. I hope to see additional datasets beyond the PATH in future studies.”
