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Study: Cannabinoid Hyperemesis Syndrome (July 2021)

Updated: Nov 28, 2023

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Cannabinoid Hyperemesis Syndrome

In July 2021, a group of researchers released a research study entitled "Cannabinoid Hyperemesis Syndrome Survey and Genomic Investigation" that was published in the journal Cannabis and Cannabinoid Research.

The objective of the study was to "investigate genetic mutations underlying [Cannabinoid Hyperemesis Syndrome] (CHS). Patients with CHS diagnosis and ongoing symptoms were compared with current cannabis users lacking symptoms."

A woman takes a shower.
What is CHS?

Cannabinoid Hyperemesis Syndrome: Genetic Source?

"We have discovered the genetic basis for an unusual syndrome. This is one of the true, unusual side effects of cannabis usage," said one of the study's authors during a 2021 interview. "You may hear from people that cannabis doesn't have side effects. That's nonsense. It's a medicine. Everything has side effects," they added.

The study described the controversial syndrome as a "relatively rare condition that is increasingly identified. The reason is the availability of higher THC potency material in most areas, so this is something that people need to know about, both in the medical community as well as consumers."

Of those who had previously attempted to cease cannabis consumption, 75% reported withdrawal symptoms that included "anxiety, depression, insomnia, and irritability."

The research involved 205 subjects who seemed to suffer from CHS and 54 control subjects. However, only 28 of the subjects and 12 controls completed genomic (genetic) testing and the overall study. This was due to a variety of factors cited by the researchers, including a refusal on the part of some participants to accept that their condition might result from THC or another chemical component produced by the plant.

This relatively small sample size has been criticized as being too small to produce scientifically relevant data. Said Vincenzo Di Marzo, a biochemist who studies cannabinoids and molecular genetics at the Université Laval in Quebec, during an interview for an article that appeared in the MIT Technology Review, "You have to validate it with much larger cohorts. I would have used a thousand patients, not just 28."

"Somewhere along the way, [participants] got cold feet," reported the study's authors. "To be honest, we had a lot of pushback from the cannabinoid hyperemesis community. There were people who questioned our motives and actually dissuaded other people from [participating]." Despite these challenges, the researchers identified five statistically significant genes that may cause CHS in some heavy cannabis consumers (those who feature a genetic predisposition, according to this study).

Patients Paranoid from Pot?

Cannabinoid Hyperemesis Syndrome. "It's hard to explain this without sounding judgmental, but people with CHS are highly suspicious of the medical community," said one of the study's authors. "It's been documented in other studies. Compliance is not very good," he reported.

Howard Hughes wears tissue boxes on his feet.
CHS patients are suspiciouis.

The study's authors explained that general practitioner doctors commonly suggest to CHS patients that they cease consumption of cannabis, but that "almost nobody can who has this." They explained that a high degree of suspicion and even paranoia is "part of the diagnosis, we're afraid."

The researchers noted that the core source of this strange disease seems to be delta-9 THC rather than a different cannabinoid or perhaps a terpene produced by the herbal plant species. Although the most common consumption avenue among CHS patients is smoking, it can also result from other forms of use, including vaporization ("vaping") and ingestion (edibles).

"Overall, there are only several hundred reported cases [of CHS] in the literature."

Of those study participants who had previously attempted to cease cannabis consumption with the goal of reducing or eliminating their negative symptoms, 75 percent reported withdrawal symptoms that included "anxiety, depression, insomnia, and irritability."

Cannabinoid Hyperemesis Syndrome Study Conclusions

"Overall, there are only several hundred reported cases [of CHS] in the literature. Although, from talking to emergency departments and gastroneurologists, they're seeing this more often. They consider it established enough that they don't report it anymore," noted one of the study's authors in an interview.

The research explained how CHS is "an unusual constellation of symptoms" that affects people solely in the context of "heavy chronic use of high-THC cannabis material" who also feature a genetic predisposition to CHS and its symptoms.

View the original study.

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