WEDNESDAY, March 20, 2019 (HealthDay News) -- Cannabis use is associated with increased odds of psychotic disorder, according to a study published online March 19 in The Lancet Psychiatry.
Marta Di Forti, Ph.D., from King's College London, and colleagues identified the patterns of cannabis use with the strongest effect on odds of psychotic disorder across Europe. The population-attributable fractions for the patterns of cannabis use associated with the highest odds of psychosis were examined, assuming causality, and the correlation between these patterns and incidence rates for psychotic disorders were assessed across study sites. Data were included for 901 patients with first-episode psychosis across 11 sites and 1,237 population controls from the same sites.
The researchers found that compared with never users, daily cannabis use correlated with increased odds of psychotic disorder (adjusted odds ratio, 3.2); for daily use of high-potency types of cannabis, the odds were increased nearly fivefold (adjusted odds ratio, 4.8). If high-potency cannabis were no longer available, 12.2 percent of cases of first-episode psychosis could be prevented across the 11 sites.
"Therefore, it is of public health importance to acknowledge alongside the potential medicinal properties of some cannabis constituents the potential adverse effects that are associated with daily cannabis use, especially of high-potency varieties," the authors write.
Several authors disclosed financial ties to the pharmaceutical industry.