Risk of emergency medical treatment following consumption of cannabis or synthetic cannabinoids in a large global sample

Background: Synthetic cannabinoids (SCs) have become increasingly popular in recent years. Diverse in chemical structure, many have been subjected to legislative regulation, but their availability and use persists. Often marketed to reflect their similar effects to cannabis, their use has been associated with a range of negative health effects. We sought to determine the relative risk of seeking emergency medical treatment (EMT) following use of SCs and natural cannabis. Methods: We utilized an anonymous online survey of drug use, obtaining data from 22,289 respondents. We calculated the relative risk of seeking EMT between the two substances using an estimate for days used in the past year. Results: Thirty-seven cannabis users (0.2%) and 21 SC users (1.0%) had sought EMT during the past year following use. The relative risk associated with the use of SCs was 30 (95% CI 17.5-51.2) times higher than that associated with cannabis. Significantly more symptoms (p=0.03) were reported by respondents seeking treatment for SCs than for cannabis. Conclusions: Whilst these findings must be treated with caution, SCs potentially pose a greater risk to users' health than natural forms of cannabis. Regulation is unlikely to remove SCs from the market, so well-informed user-focused health promotion messages need to be crafted to discourage their use.