Michigan EDs See Jump in Cannabis-Related Neuropsychiatric Toxicity

— Community-based study reports “troublesome” data in state that legalized marijuana for adults

by Ryan Basen, Enterprise & Investigative Writer, MedPage Today October 30, 2021


Neuropsychiatric toxicity (NPS) was common among patients presenting with cannabis toxicity to Michigan emergency departments (EDs), and they were more likely to also have used other substances, a researcher reported.

In the community-based analysis, among more than 1,000 patients presenting with cannabis toxicity over 2 years, 39.8% also were diagnosed with NPS, most often severe anxiety (36.1%) and altered mental status (22.3%), according to Erin Leach, a fourth-year medical student at the University of Michigan in Grand Rapids.

Legalized Cannabis in Colorado Emergency Departments: A Cautionary Review of Negative Health and Safety Effects

Brad A. Roberts, MD

Cannabis legalization has led to significant health consequences, particularly to EDs and hospitals in Colorado. The most concerning include psychosis, suicide, and other substance abuse. There are deleterious effects on the brain and some of these may not be reversible with abstinence. Other significant health effects include increases in fatal motor vehicle collisions, adverse effects on cardiovascular and pulmonary systems, inadvertent pediatric exposures, cannabis contaminants exposing users to infectious agents, heavy metals, and pesticides, and hash-oil burn injuries due to preparation of concentrates. Finally, cannabis dispensary workers not trained in medicine are giving medical advice that could be harmful to patients.

Cannabis research may offer opportunities for novel treatment of seizures, spasticity from multiple sclerosis, nausea and vomiting from chemotherapy, chronic pain, improvements in cardiovascular outcomes, and sleep disorders. However, progress has been difficult due to absent standardization of the chemical composition of cannabis products and limitations on research secondary to federal classification of cannabis. Given these factors and the Colorado experience, other states should carefully evaluate whether and how to decriminalize or legalize non-medical cannabis use.


Acute Illness Associated With Cannabis Use, by Route of Exposure

Andrew A. Monte, MD, PhDShelby K. Shelton, MPHEleanor Mills, BSJessica Saben, PhD… View all authors Author, Article and Disclosure Informationhttps://doi.org/10.7326/M18-2809

April 16, 20199


There were 9973 visits with an ICD-9-CM or ICD-10-CM code for cannabis use. Of these, 2567 (25.7%) visits were at least partially attributable to cannabis, and 238 of those (9.3%) were related to edible cannabis. Visits attributable to inhaled cannabis were more likely to be for cannabinoid hyperemesis syndrome (18.0% vs. 8.4%), and visits attributable to edible cannabis were more likely to be due to acute psychiatric symptoms (18.0% vs. 10.9%), intoxication (48% vs. 28%), and cardiovascular symptoms (8.0% vs. 3.1%). Edible products accounted for 10.7% of cannabis-attributable visits between 2014 and 2016 but represented only 0.32% of total cannabis sales in Colorado (in kilograms of tetrahydrocannabinol) during that period.


Retrospective study design, single academic center, self-reported exposure data, and limited availability of dose data.


Visits attributable to inhaled cannabis are more frequent than those attributable to edible cannabis, although the latter is associated with more acute psychiatric visits and more ED visits than expected.

Emergency Department Visits From Edible Versus Inhalable Cannabis

The legalization of cannabis in a growing number of states coupled with the perception that marijuana is an innocuous drug has led to significant increases in cannabis consumption, both for its recreational properties and for its alleged medicinal properties. However, cannabis use is associated with adverse health effects (1), and cannabis-related emergency department (ED) visits and hospital admissions have increased (2).

In this issue, Monte and colleagues reviewed health records from patients presenting to the UCHealth University of Colorado Hospital Emergency Department from 2012 to 2016 and found a more than 3-fold increase in cannabis-associated ED visits over this period ..