Increasing Use of Cannabis Among Older Adults in the U.S. and Canada

By Isabelle Miles, MD, and Fernanda Bellolio, MD, MSc, on behalf of the SAEM Academy For Geriatric Emergency Medicine

Cannabis use has exponentially grown over the past few years with legalization in multiple U.S. states. At the same time, emergency department (ED) visits for cannabis-related adverse events, such as accidental overdose, and intoxication, have increased.

The rate of cannabis use by older adults is increasing more quickly than all other age groups. Older adult beliefs about cannabis use are shifting secondary to legalization, broader social acceptance, and perceived benefits for treatment of chronic conditions. With decrease perception of risk, cannabis use, including high risk use and intoxication, has increased. A study demonstrated that ED visits in California increased from 21 per 100,000 visits in 2005 to 395 per 100,000 ED visits in 2019 — a 1804% relative increase.

Consequently, increased public health education is needed to improve health literacy about cannabis use.

Cannabis is composed of many phytocannabinoids, with delta-9tetrahydrocannabinol (THC) and cannabidiol (CBD) causing most of the effects. THC is responsible for most of the psychotropic effects, including intoxication and re-enforcing properties.

CBD is thought to be non-psychoactive, with anti-inflammatory, analgesic, and immunomodulatory properties. It can attenuate some of the negative effects of THC in appropriate ratios. Cannabis can be purchased in many forms (edibles, oils, tinctures, dried plant) and different combinations of concentrations and ratios of THC and CBD. Over time, THC concentrations have increased to 14% or more, while cannabidiol has decreased relatively in combination products; this has been linked to increasing ED presentations related to cannabis.

Medical cannabis is used for several conditions, including pain and insomnia, but evidence supporting these practices is lacking. In one large survey of adults using medical cannabis, cannabis oil was used by 80% of older adults. Among those using cannabis for pain control, 36% reported it helped reduce their total opioids use, and 20% reported it reduced the use of benzodiazepines. However good efficacy data in older adults are lacking and reviews thus far demonstrate significant uncertainty around benefits

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for pain management. Side effects include dizziness (18%), nausea (9%), dry mouth (9%), and tinnitus (9%). These are reflected in other studies reviewing cannabis for pain management, where NNT (number needed to treat) for pain relief often overlap with NNH (number needed to harm). Some studies suggest that older adults are at increased risk of developing cannabis use disorder, particularly if there is concurrent substance use.

Evaluation of the cognitive function and emotional functioning among adults aged 60 and older demonstrated that long-term consumers had decreased executive function, processing speed, and general cognition. Additionally, increased frequency of use was negatively associated with working memory. Long-term recreational cannabis use is associated with lower executive function and processing speed in older adults. In the general population, some of these effects are not reversible even after 6 months of abstinence.

Older adults want more information about cannabis and desire to communicate with their health care providers. Asking about cannabis use and providing education should be a part of routine medical care for older adults. Current low risk guidelines are available to providers to guide conversation around reducing long term risk associated with cannabis use.

Stay tuned for our upcoming Guidelines for Reasonable and Appropriate Care in the Emergency Department (GRACE) on non-opioid substance dependence including management of cannabis hyperemesis syndrome, coming later this year!

About The Authors

Dr. Milles is an emergency physician and addiction medicine specialist in the Department of Emergency Medicine and Division of Addiction Medicine, St Paul's Hospital, Vancouver, BC. Department of Emergency Medicine, University of British Columbia, Vancouver, BC. She is a member of the GRACE-4 committee.

Dr. Bellolio is a professor of emergency medicine in the Department of Emergency Medicine, Department of Health Sciences Research, Division of Health Care Policy and Research, and Department of Medicine, Section of Geriatric Medicine at Mayo Clinic, Rochester, MN. She is a member-at-large of AGEM, and a methodologist for the GRACE guidelines.

The Academy of Geriatric Emergency Medicine (AGEM) works to improve the clinical care of older patients, prepare trainees to care for older patients, and advance the geriatric EM research agenda. Joining AGEM is free! Just log into your member profile. Click “My Account” in the upper right navigation bar. Click the “Update (+/-) Academies and Interest Groups” button on the left side. Select the box next to the academy you wish to join. Click “save.”