Growing Concerns for Cannabis Users
Disturbing new research findings raise concerns about cannabis usage.
Posted March 30, 2026 | Reviewed by Monica Vilhauer Ph.D.
While the recent legalization of cannabis in many jurisdictions in North America has led to greater acceptance of and a rise in cannabis usage, research findings on the impacts of cannabis continue to raise concerns among medical and mental health professionals, and in the public.
A study of Canadian attitudes regarding cannabis usage and safety five years following its legalization, for example, found that while cannabis usage has become more acceptable, concerns about use disorders, its usefulness in treating anxiety , depression , and other mental health conditions, and concerns about its impacts on overall health and well-being are on the rise.
As for the current state of cannabis usage, the numbers tell the story. Whitney Economics, a global leader in cannabis business consulting, predicts 2026 legal revenues of $30.5 billion, an increase of over four percent from 2025. According to Pew Research, as of July 2025, eight out of 10 Americans live in a county with one or more cannabis dispensaries. In Canada, where cannabis usage has been legal since 2018, cannabis is widely available in retail stores and online. According to the Canadian Centre for Substance Use and Addiction , cannabis usage has risen a whopping 40 percent since 2017.
Knowing what is good for us — and what is not — is critical to making healthy choices that support our physical and mental health and overall well-being. Here’s a look at some of the latest research on the impacts of cannabis usage.
Cannabis and mental health treatment
Research published in April 2026 in The Lancet on the efficacy and safety of cannabis for treating mental health disorders reported very little evidence supporting its effectiveness in treating anxiety, depression, post- traumatic stress disorder ( PTSD ), and other conditions. In an interview with CNN, Jack Wilson, lead author of the study and postdoctoral research fellow at the University of Sydney’s Matilda Centre for Research in Mental Health and Substance Use explained: “We found no evidence any form of cannabis is effective in treating anxiety, depression or post-traumatic stress disorder, which are three of the leading reasons for which cannabis is prescribed.” These findings align with research published in JAMA in March of this year and with earlier research published in 2019.
Rising concerns for usage among teens and young adults
A recent study out of McGill University that linked cannabis usage to health records identified daily or near-daily cannabis usage before the age of 15 to individuals seeking treatment for mental health conditions, including depression, anxiety, and suicidal distress, as well as respiratory conditions and injuries.
A recent study from the School of Public Health at the University of Saskatchewan, measuring speed, reaction time, and crash rates, found that 75 percent of teens and young adults crashed in driving simulation tests up to 6 hours after consuming 1 mg of cannabis with THC. (Full study findings are yet to be published.)
Concerning findings of a recent cross-sectional study of 1003 young adults, which suggests a troubling impact of cannabis use on brain function, “suggest that cannabis use is associated with short- and long-term brain function outcomes, especially during working memory tasks.”
Vaping and cannabis usage
Cannabis hyperemesis syndrome (CHU) is a serious condition linked to frequent cannabis usage, with troubling symptoms, including severe nausea, vomiting, and abdominal pain. A 2025 study examining emergency room visits related to CHU found that, in 2022, the rate rose to 22.3 per 100,000, from 4.4 per 100,000 in 2016. A recently published study exploring cannabis use patterns in individuals suffering from CHU found the use of vape cartridges to be linked to a shorter timeframe in developing CHS symptoms. This new research further raises concerns around the potential impacts of vaping cannabis on lung health.
An expanding list of concerns
These new research findings, as well as recent research on the risks of cannabis usage for seniors, rising awareness of the combined risks of regular cannabis and alcohol use, and the long-recognized risks of habitual cannabis usage, including cannabis use disorder, cast a shadow over the pleasant side effects of recreational cannabis use.
The reality is that knowledge is power, and the more we know about the potential risks and problematic impacts of cannabis usage on our mental and physical health, the better able we are to make informed choices, recognize and manage our symptoms, and create habits that support our health and happiness .
5 steps to assessing and managing your cannabis consumption
If you are concerned about recent research findings about the impacts of cannabis usage, it is important to build an awareness of your habits and symptoms, and to take action if you would like to take control of your cannabis usage. You can:
To find a therapist, visit the Psychology Today Therapy Directory .
Share this post Facebook Bluesky Linkedin Email
There was a problem adding your email address. Please try again.
By submitting your information you agree to the Psychology Today Terms & Conditions and Privacy Policy
Monica Vermani, C. Psych., is a clinical psychologist specializing in the treatment of trauma, stress, mood and anxiety disorders, and the author of A Deeper Wellness .
Get the help you need from a therapist near you–a FREE service from Psychology Today.
This article is part of the Bringwise Psychology Journal — daily insights on human behavior, mental health, and personal growth.