As cannabis use among youth rises in Canada — and THC potency reaches record highs — emergency departments are seeing a surge in cases of a once-rare condition: cannabis hyperemesis syndrome (CHS).

Characterized by relentless vomiting, abdominal pain and temporary relief through compulsive hot showers or baths, CHS is increasingly affecting adolescents and young adults. Yet few people — including many clinicians — know it exists.

Canada ranks among the highest globally for youth cannabis use, with 43 per cent of 16-19-year-olds reporting use in the past year. Usage peaks among those 20–24 years, with nearly half (48 per cent) reporting past-year use.

This rise in regular, heavy use coincides with a 400 per cent increase in THC potency since the 1980s. Strains with THC levels above 25 per cent are now common. As cannabis becomes more potent and accessible, clinicians are seeing more cases of CHS, a condition virtually unheard of before 2004.

CHS unfolds in three phases:

1. Prodromal phase: Nausea and early morning discomfort begin. Users increase cannabis consumption, thinking it will relieve symptoms.

2. Hyperemetic phase: Intense vomiting, dehydration and abdominal pain follow. Hot showers or baths provide temporary relief — a hallmark of CHS.

3. Recovery phase: Symptoms resolve after stopping cannabis entirely.

Diagnosis is often delayed. One reason is because CHS mimics conditions like gastroenteritis or eating disorders, leading to costly CT scans, MRIs and gastric emptying tests. One telltale sign — compulsive hot bathing — is frequently overlooked, despite its strong diagnostic value.

Youth face unique risks. The brain continues to develop until about age 25, and THC exposure during this critical window can impair cognitive functions like memory, learning and emotional regulation. Heavy cannabis use is associated with heightened risks of anxiety, depression, psychosis and self-harm.

Edit, the link in the article goes to this study:

Just a moment...

(jamanetwork.com)

Results There were 12 866 ED visits for CHS from 8140 individuals during the study. Overall, the mean (SD) age was 27.4 (10.5) years, with 2834 individuals (34.8%) aged 19 to 24 years, 4163 (51.5%) females, and 1353 individuals (16.6%) with a mental health ED visit or hospitalization in the 2 years before their first CHS ED visit. Nearly 10% of visits (1135 visits [8.8%]) led to hospital admissions. Monthly rates of CHS ED visits increased 13-fold during the 7.5-year study period, from 0.26 visits per 100 000 population in January 2014 to 3.43 visits per 100 000 population in June 2021. Legalization was not associated with an immediate or gradual change in rates of ED visits for CHS; however, commercialization during the COVID-19 pandemic period was associated with an immediate increase in rates of CHS ED visits (incidence rate ratio [IRR], 1.49; 95% CI, 1.31-1.70). During commercialization, rates of CHS ED visits increased more in women (IRR, 1.49; 95% CI, 1.16-1.92) and individuals older than the legal age of cannabis purchase (eg, age 19-24 years: IRR, 1.60; 95% CI, 1.19-2.16) than men (IRR, 1.08; 95% CI, 0.85-1.37) and individuals younger than the legal age of purchase (IRR, 0.78; 95% CI, 0.42-1.45).

If you think marijuana and alcohol are equally harmful then you aren’t qualified to walk and chew at the same time

Several more paragraphs of alarmist drug war bullshit, didn’t work the first time idk why you’d think repeating the same failed strategy would yield different results.

I never said smoking anything was safe or harmless, I said marijuana was safer than any other recreational drug by far regardless of ingestion method, and that any method other than inhalation completely negates any respiratory effects.

Your first study, linked directly because it’s actually really easy to do https://pmc.ncbi.nlm.nih.gov/articles/PMC8229290/

From the conclusion: “…data are not sufficiently strong to suggest that cannabis use adversely affects the progression of viral diseases…it is also evident that cannabis or its constituents, including THC and CBD, have some beneficial effects such as improving appetite and food intake in patients with HIV/AIDS and positive effects in patients with hepatic steatosis”

So not only does your first source not support your claims, it actually says a whole bunch of the opposite!

Your second study https://pmc.ncbi.nlm.nih.gov/articles/PMC7442038/

Again, direct quotes: “We have evidence suggesting that cannabis use, primarily THC in cannabis, in genetically predisposed or at-risk populations, leads to earlier diagnosis of psychosis/schizophrenia.”

Oh hey look, that’s literally exactly what I said! And it goes on

“Recent trials in therapeutic CBD use are showing its alleviating effect on positive symptoms of schizophrenia and its opposing effect on THC, which warrants further research.”

So not only is there no evidence of any risk of psychosis or schizophrenia for anyone who isn’t already genetically predisposed, but there’s actually evidence that specific cannabinoids in isolation can alleviate symptoms! Wow, another source betrays you

Your third study https://www.sciencedirect.com/science/article/abs/pii/S014976341100073X

And more direct quotes that clearly illustrate how stupid you are: “…cannabis use is clearly not an essential or sufficient risk factor as not all schizophrenic patients have used cannabis and the majority of cannabis users do not develop schizophrenia.”

I don’t doubt for a moment that you could post a dozen more studies, and I’m just as certain that they’d all also do nothing to support your inane claims. You lose! If you had any dignity at all you’d admit it, but I think we both know you don’t.

I truly appreciate the time you took to read the studies. I respect that, however, the personal attacks are unwarranted, and you’re more than welcome to debate the experts who’ve compiled the data, if you like.

Let’s take things one at a time, but it should also be noted that much of the research cited are medicinal users of cannabis (including those prescribed by doctors), not recreational, which is what the actual OP is about. You avoided touching on any of those from the long list by the Canadian Centre on Substance Use and Addiction.

Your first study, linked directly because it’s actually really easy to do https://pmc.ncbi.nlm.nih.gov/articles/PMC8229290/

From the conclusion: “…data are not sufficiently strong to suggest that cannabis use adversely affects the progression of viral diseases…it is also evident that cannabis or its constituents, including THC and CBD, have some beneficial effects such as improving appetite and food intake in patients with HIV/AIDS and positive effects in patients with hepatic steatosis”

You conveniently left out the parts before that:

"Research suggests a link between cannabis, immune function, and viral infections. Cannabis use may be associated with adverse effects on immune function and, thereby, increase the risk of acquiring or transmitting infections such as HIV and HCV. "

The part you bring up has to do with viral progression, which is different. And the fact that more research is needed in this area (per the study), doesn’t clear cannabis from harm.

The benefits of increased appetite in someone who is dying is great! Too bad, that has no relevance to the general population, so the risks outweigh the benefits.

Your second study https://pmc.ncbi.nlm.nih.gov/articles/PMC7442038/

Again, direct quotes: “We have evidence suggesting that cannabis use, primarily THC in cannabis, in genetically predisposed or at-risk populations, leads to earlier diagnosis of psychosis/schizophrenia.”

That doesn’t appear to be the study I linked, but we agree, increased risks.

But why did you skip the most important parts of the conclusion?

"Neuroimaging studies show the detrimental effect of cannabis on brain morphology, especially adolescent brains. "

“…there is still more harm from cannabis than benefits, and adolescent cannabis usage should be discouraged at all costs.”

That’s pretty damning for something considered safe, wouldn’t you agree?

“Recent trials in therapeutic CBD use are showing its alleviating effect on positive symptoms of schizophrenia and its opposing effect on THC, which warrants further research.”

So not only is there no evidence of any risk of psychosis or schizophrenia for anyone who isn’t already genetically predisposed, but there’s actually evidence that specific cannabinoids in isolation can alleviate symptoms! Wow, another source betrays you

Trials… therapeutic CBD… that sounds considerably different from recreational use outside of a medical setting, no? Like the type of use they would like to see discouraged “at all costs”.

Anyway, the study I linked is: https://pmc.ncbi.nlm.nih.gov/articles/PMC5984096/

“In summary, a genetic approach—representing an alternative to assessing causality when a randomized controlled trial would be unethical—strongly supports the hypothesis that use of cannabis is causally related to risk of schizophrenia.”

Your third study https://www.sciencedirect.com/science/article/abs/pii/S014976341100073X

And more direct quotes that clearly illustrate how stupid you are: “…cannabis use is clearly not an essential or sufficient risk factor as not all schizophrenic patients have used cannabis and the majority of cannabis users do not develop schizophrenia.”

This was my oversight, and I apologize for that.

That review paper was quite outdated, and the same author has a much more recent study available: https://pmc.ncbi.nlm.nih.gov/articles/PMC7646282/

“In conclusion, our findings confirm previous evidence of the harmful effect on mental health of daily use of cannabis, especially of high-potency types. Importantly, they indicate for the first time how cannabis use affects the incidence of psychotic disorder. Therefore, it is of public health importance to acknowledge alongside the potential medicinal properties of some cannabis constituents the potential adverse effects that are associated with daily cannabis use, especially of high-potency varieties.”

I hope that covers it. There seems to be more than enough evidence to suggest that cannabis is not safe, even for being the “safest recreational drug”.

Edit: grammar/spelling.

As abuse. Like if somebody tokes on the weekend or has a single beer neither is a problem.

As I mentioned prior I know people that have abused it to point of psychosis hospitalization, and completely destroying their job/education. You just have to define the amounts for abuse, and those will be different per drug.

They’re not even close to the same

Idk what part of “you lost” is confusing you, you have been proven completely wrong and as predicted you refuse to admit it. The personal attacks are entirely warranted, you’re a lying sack of shit.

I’m sorry that your mental health is in such a bad state.

I read in your other comment that you’ve been a daily cannabis user for decades, and now I can understand your aggressive defense of the drug, and your unhinged behaviour.

I wish you said that sooner. Your agenda is to defend your addiction, so there was never an honest discussion here.

It was fun. Get some help.

You are being down voted but this exact thing happened to somebody I know. The repeal of criminalization, without a better education plan, gave them the idea that “Oh its fine now”. They became addicted to smoking it, spent all day every day just hitting a bong. Stopped working, had to repeat a year at uni to get courses on track. They’ve had to completely abstain, or they fall back into the spiral. Some people get addicted to alcohol, some its another drug entirely.

Have you had psychosis from a beer every day? Notice I’m not saying they are the same, but all drugs can do damage if overused. Heroine has no side affects after it wears off, but will end you with slightly too much. If I over drink caffeine my blood pressure skyrockets and I’m a candidate for something bursting and dying of an internal bleed. For me coffee is dangerous.

You’re not sorry for shit, you’re just upset that you got caught deliberately misrepresenting the contents of those studies, and now you’re looking to do the same thing about me personally because you don’t have to a leg to stand on and you know it. Nobody ever calls daily coffee drinkers addicts, it’s psychoactive and far easier to die from. Your bullshit is painfully obvious and nobody is buying it. Get a job.

Nobody who isn’t already hereditarily predisposed to psychosis has ever developed psychosis from cannabis consumption. Nobody has ever required an organ transplant due to cannabis consumption either. Heroine absolutely does have long-term negative effects, marijuana has none outside of respiratory effects which can be completely avoided with any other method of ingestion. Quit lying.

I’m being downvoted because addicts have to defend and justify their addiction, unfortunately.

I had a family member who also went through the same. They developed psychosis (Cannabis-induced depersonalization-derealization disorder) through daily use of cannabis, and ended up needing to get treatment after their life went downhill.

Stopped once the weed stopped, but it was an alarming transition, and not an easy addiction to break.

They only became hooked once legalization came into effect, since it was accessible from anywhere.

Some bold claims. The life style around heroine addiction has negative affects, but per experts it is a connector that is done when it pops off. Out of the entire world drinking responsibly how many organ transplants are there? Its those who overuse that are an issue. The drunk driver is no different than my high neighbour that smashed through a gate, that gate could have easily been a person. I don’t claim marijuana is horrible but the best argument people who use marijuana come up with is " well it’s not alcohol, alcohol is worse". That whataboutism is dangerous when people think that equates to over indulgence is without risk.

you’re just upset that you got caught deliberately misrepresenting the contents of those studies

I’m not upset about anything. The studies speak for themselves.

and now you’re looking to do the same thing about me personally because you don’t have to a leg to stand on and you know it.

No, that extra bit of information gives me context for understanding where you’re coming from.

You were never going to be receptive of the facts, because they’d contradict the story you’ve been telling yourself about the “safest” harmful recreational drug.

I just never realized that was your motivation until just now.

Nobody ever calls daily coffee drinkers addicts

Who’s arguing about coffee, anyway?

I’m being downvoted because addicts have to defend and justify their addiction, unfortunately.

I had a family member who also went through the same. They developed psychosis (Cannabis-induced depersonalization-derealization disorder) through daily use of cannabis, and ended up needing to get treatment after their life went downhill.

Stopped once the weed stopped, but it was an alarming transition, and not an easy addiction to break.

They only became hooked once legalization came into effect, since it was accessible from anywhere.

As cannabis use among youth rises in Canada — and THC potency reaches record highs — emergency departments are seeing a surge in cases of a once-rare condition: cannabis hyperemesis syndrome (CHS).

Characterized by relentless vomiting, abdominal pain and temporary relief through compulsive hot showers or baths, CHS is increasingly affecting adolescents and young adults. Yet few people — including many clinicians — know it exists.

Canada ranks among the highest globally for youth cannabis use, with 43 per cent of 16-19-year-olds reporting use in the past year. Usage peaks among those 20–24 years, with nearly half (48 per cent) reporting past-year use.

This rise in regular, heavy use coincides with a 400 per cent increase in THC potency since the 1980s. Strains with THC levels above 25 per cent are now common. As cannabis becomes more potent and accessible, clinicians are seeing more cases of CHS, a condition virtually unheard of before 2004.

CHS unfolds in three phases:

1. Prodromal phase: Nausea and early morning discomfort begin. Users increase cannabis consumption, thinking it will relieve symptoms.

2. Hyperemetic phase: Intense vomiting, dehydration and abdominal pain follow. Hot showers or baths provide temporary relief — a hallmark of CHS.

3. Recovery phase: Symptoms resolve after stopping cannabis entirely.

Diagnosis is often delayed. One reason is because CHS mimics conditions like gastroenteritis or eating disorders, leading to costly CT scans, MRIs and gastric emptying tests. One telltale sign — compulsive hot bathing — is frequently overlooked, despite its strong diagnostic value.

Youth face unique risks. The brain continues to develop until about age 25, and THC exposure during this critical window can impair cognitive functions like memory, learning and emotional regulation. Heavy cannabis use is associated with heightened risks of anxiety, depression, psychosis and self-harm.

Edit, the link in the article goes to this study:

Just a moment...

(jamanetwork.com)

Results There were 12 866 ED visits for CHS from 8140 individuals during the study. Overall, the mean (SD) age was 27.4 (10.5) years, with 2834 individuals (34.8%) aged 19 to 24 years, 4163 (51.5%) females, and 1353 individuals (16.6%) with a mental health ED visit or hospitalization in the 2 years before their first CHS ED visit. Nearly 10% of visits (1135 visits [8.8%]) led to hospital admissions. Monthly rates of CHS ED visits increased 13-fold during the 7.5-year study period, from 0.26 visits per 100 000 population in January 2014 to 3.43 visits per 100 000 population in June 2021. Legalization was not associated with an immediate or gradual change in rates of ED visits for CHS; however, commercialization during the COVID-19 pandemic period was associated with an immediate increase in rates of CHS ED visits (incidence rate ratio [IRR], 1.49; 95% CI, 1.31-1.70). During commercialization, rates of CHS ED visits increased more in women (IRR, 1.49; 95% CI, 1.16-1.92) and individuals older than the legal age of cannabis purchase (eg, age 19-24 years: IRR, 1.60; 95% CI, 1.19-2.16) than men (IRR, 1.08; 95% CI, 0.85-1.37) and individuals younger than the legal age of purchase (IRR, 0.78; 95% CI, 0.42-1.45).

You’re being downvoted for pushing verifiably false drug war talking points, lying about the contents of the studies you linked, and accusing everyone who points any of that out/proves you wrong of being addicts. You’re a mess bud, seek professional help.

You lost, the only honest response from here is for you to admit it and move on like an adult

This feels like playing chess with a pigeon, TBH.

Ok, buddy. “You win.”