Legalized Cannabis in Colorado Emergency Departments

A Cautionary Review of Negative Health and Safety Effects

Brad A. Roberts, MD


Western J Emerg Med. 2019;20(4):557-572. 

In This Article


This was not a systematic review of the literature but rather a summary of selected research including several large reviews from the NASEM, the WHO, and the CDPHE. There is undoubtedly much literature, some of it conflicting, not cited here. However, as other states and countries wrestle with decriminalization and legalization of cannabis for personal use and sale, it is crucial to report the Colorado experience as a cautionary tale. This review summarizes a large body of research for practicing emergency physicians who are increasingly confronted with questions and patients who use cannabis. Although the author practices in Colorado, the information is likely generalizable. This review clearly reflects the author's biases, yet its composition was motivated by alarming experience in everyday practice.

Discussions of cannabis' effects are relevant not only to the healthcare system, but to legal, business, environmental, legislative, and other branches within a public health framework. This article does not address those other facets. Neither have numerous other physiological effects of cannabis been reviewed here. Many of the previous research studies have focused on cannabis with a much lower THC level limiting applicability to cannabis sold at dispensaries today. Finally, the words "marijuana" and "cannabis" were used interchangeably throughout the article. This was done to maintain the wording from the studies cited consistent with their original language. No difference should be implied with the alternating use of these terms.