Colorado emergency departments are seeing more cannabis-related illnesses since legalization | Research

The takeaway

Four years after legalization in Colorado, emergency departments reported increases in CHS, acute psychosis, cannabinoid catatonia, cardiac events, pediatric exposures, and hash-oil burn injuries.

Emergency physicians, policymakers in states considering legalization, and heavy cannabis users.

THC per joint: from 1-3 mg in the 1990s to 18+ mg today

What the researchers found

Post-legalization ED presentations include cannabinoid hyperemesis, acute psychosis, cannabinoid catatonia syndrome, acute myo-pericarditis, pediatric ingestions, increases in fatal motor vehicle collisions, and hash-oil burn injuries. THC concentrations have risen dramatically (from 1-3 mg per joint in the 1990s to 18+ mg today). Some patients self-report using 2,000+ mg of THC daily.

Why it matters

Colorado was one of the first states to legalize recreational cannabis, making it a natural experiment. The ED data provides a real-world picture of health consequences that laboratory studies cannot capture.

The numbers in context

1990s joints: 1-3 mg THC. Current Colorado joints: 18+ mg THC. Some patients self-report 2,000+ mg THC/day. In 2015, 2.6 million new cannabis users, 45% aged 12-17.

How the study worked

Narrative review of cannabis-related health and safety effects observed in Colorado emergency departments over four years of legalization.

What this study cannot tell us

Narrative review from one state. Does not include systematic data collection or comparison to pre-legalization rates. Some conditions (like CHS) may have been underdiagnosed previously.

How to read the evidence

Moderate: firsthand clinical observation from a major legalization state, but narrative review without systematic methodology.

When this study was published

Published in 2019.

The bigger picture

As more states and countries legalize cannabis, the Colorado experience serves as a preview of potential health system impacts. The dramatic increase in THC potency is a key factor in the severity of presentations.

Questions still open

Are these increases proportional to the increase in use, or is higher-potency cannabis producing more harm per user? Would regulatory limits on THC concentration reduce ED presentations? How do other legalized states compare?

Common questions

What is cannabinoid catatonia syndrome?

A newly described condition seen in Colorado EDs where heavy cannabis users present with a catatonia-like state. It is distinct from traditional catatonia and appears related to high-dose THC exposure.

Does legalization cause more health problems?

This review documents increased ED presentations but cannot definitively attribute them solely to legalization. Increased reporting, higher potency products, and greater use all likely contribute.

Read the original research

Emergent Medical Illnesses Related to Cannabis Use.

Missouri medicine, 116(3), 226-228

View on PubMed ↗

Citation

Randall, Karen; Hayward, Kathleen. (2019). Emergent Medical Illnesses Related to Cannabis Use.. Missouri medicine, 116(3), 226-228.