Daily Cannabis Use Linked to Higher Psychosis Risk

Daily cannabis use is associated with significantly increased risk of developing psychosis, according to the results of a recent study.

While cannabis use has been shown to increase risk of later psychotic disorder, whether it affects incidence of the disorder remains unclear, according to the authors. 

Read more...

Cannabis Use in Adolescence Linked With Depression, Suicidality

Many Medical Cannabis Users Report Driving While “Very High”

To evaluate the effects of various patterns of cannabis use on risk of psychotic disorder, the researchers conducted a case-control study involving 901 patients with first episode of psychosis and 1237 controls from 11 sites in Europe and Brazil. The patients were aged 18 to 64 years.

Overall, they found that daily cannabis use was associated with increased odds of psychotic disorder compared with no cannabis use (adjusted odds ratio [OR] 3.2), which increased with high-potency cannabis (OR 4.8).

“In conclusion, our findings confirm previous evidence of the harmful effect on mental health of daily use of cannabis, especially of high-potency types. Importantly, they indicate for the first time how cannabis use affects the incidence of psychotic disorder,” they concluded.

“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.”

—Michael Potts

Reference:

Forti MD, Quattrone D, Freeman TP, et al. The contribution of cannabis use to variation in the incidence of psychotic disorder across Europe (EU-GEI): a multicentre case-control study [published online March 19, 2019]. Lancet Psychiatry. doi: https://doi.org/10.1016/S2215-0366(19)30048-3