A cautionary review of health effects seen in Colorado after cannabis legalization

Since legalization in Colorado, health consequences observed include psychosis, suicide, other substance abuse, cognitive impairments, fatal motor vehicle collisions, cardiovascular and pulmonary effects, pediatric exposures, contaminant risks, and hash-oil burn injuries.

Roberts, Brad A·The western journal of emergency medicine·2019·Moderate EvidenceReview
RTHC-02257ReviewModerate Evidence2019RETHINKTHC RESEARCH DATABASErethinkthc.com/research

Quick Facts

Study Type
Review
Evidence
Moderate Evidence
Sample
Not reported

What This Study Found

The most concerning effects were psychosis, suicide, and other substance abuse. Cognitive impairments may not be reversible with abstinence. Additional concerns include fatal motor vehicle collisions, cardiovascular and pulmonary damage, pediatric exposures, contaminants (infectious agents, heavy metals, pesticides), and hash-oil burns. "Budtenders" provide medical advice without medical training.

Key Numbers

Multiple categories of harm documented. Cannabis research may benefit seizures, MS spasticity, chemo nausea, chronic pain, cardiovascular outcomes, and sleep disorders.

How They Did This

Narrative review of health and safety effects observed in Colorado emergency departments since cannabis legalization.

Why This Research Matters

Colorado is a real-world natural experiment in cannabis legalization. This review catalogs the negative health consequences that other states should anticipate and prepare for.

The Bigger Picture

The review presents a balanced view: acknowledging potential medical benefits while documenting significant real-world harms. The lack of standards for cannabis product composition and federal research restrictions are identified as barriers to progress.

What This Study Doesn't Tell Us

Narrative review from one state. No systematic data collection or pre/post comparison. May overrepresent emergency presentations relative to overall population experience.

Questions This Raises

  • ?How do other legalized states compare to Colorado?
  • ?Would stricter product regulations reduce these harms?
  • ?Can "budtender" advice be regulated or replaced with trained professionals?

Trust & Context

Key Stat:
Psychosis, suicide, and substance abuse are the most concerning post-legalization effects
Evidence Grade:
Moderate: comprehensive narrative review of a unique natural experiment, but lacks systematic methodology.
Study Age:
Published in 2019.
Original Title:
Legalized Cannabis in Colorado Emergency Departments: A Cautionary Review of Negative Health and Safety Effects.
Published In:
The western journal of emergency medicine, 20(4), 557-572 (2019)
Database ID:
RTHC-02257

Evidence Hierarchy

Meta-Analysis / Systematic Review
Randomized Controlled Trial
Cohort / Case-Control
Cross-Sectional / ObservationalSnapshot without intervening
This study
Case Report / Animal Study

Summarizes existing research on a topic.

What do these levels mean? →

Frequently Asked Questions

Does the review say legalization was a mistake?

The review does not take a definitive position but urges other states to carefully evaluate the evidence before legalizing. It acknowledges both medical potential and documented harms.

What are "budtenders"?

Dispensary employees who sell cannabis products. The review notes they often provide medical advice without medical training, which can be harmful to patients.

Read More on RethinkTHC

Cite This Study

RTHC-02257·https://rethinkthc.com/research/RTHC-02257

APA

Roberts, Brad A. (2019). Legalized Cannabis in Colorado Emergency Departments: A Cautionary Review of Negative Health and Safety Effects.. The western journal of emergency medicine, 20(4), 557-572. https://doi.org/10.5811/westjem.2019.4.39935

MLA

Roberts, Brad A. "Legalized Cannabis in Colorado Emergency Departments: A Cautionary Review of Negative Health and Safety Effects.." The western journal of emergency medicine, 2019. https://doi.org/10.5811/westjem.2019.4.39935

RethinkTHC

RethinkTHC Research Database. "Legalized Cannabis in Colorado Emergency Departments: A Caut..." RTHC-02257. Retrieved from https://rethinkthc.com/research/roberts-2019-legalized-cannabis-in-colorado

Access the Original Study

Study data sourced from PubMed, a service of the U.S. National Library of Medicine, National Institutes of Health.

This study breakdown was produced by the RethinkTHC research team. We analyze and report published research findings without making health recommendations. All interpretations are based solely on the published abstract and study data.