On December 18th, 2025, President Trump signed Executive Order 14370 that would reschedule marijuana from a Schedule I drug to Schedule III. This change would reclassify marijuana as a drug that has an acceptable medical use with less potential for abuse than Schedule I drugs, where it is now. It would also make it easier to pursue research on marijuana use, whether that use would be for medical or recreational reasons. That research could help clarify the disturbing association of heavy marijuana use and issues such as CHS—cannabinoid hyperemesis syndrome—and psychosis.
CHS or scromiting is a relatively recent medical condition affecting cannabis users that combines severe nausea, vomiting and actual screaming from debilitating abdominal pain. It was first identified by Australian researchers in 2004: “Cannabinoid hyperemesis: cyclical hyperemesis in association with chronic cannabis use.” The Cleveland Clinic said the repeated vomiting from CHS can happen up to five times an hour. Hot baths and showers seem to help reduce the symptoms and many people with CHS compulsively shower or bathe to relieve CHS symptoms. “Scromiting” refers to the intense pain with CHS, which causes you to scream when you vomit.
Scientists don’t yet know the exact cause of CHS. But the main theory is that it may happen due to long-term overstimulation of receptors in your endocannabinoid system (ECS). This may lead to issues with your body’s natural control of nausea and vomiting.
People who use marijuana long-term—typically for 10 or 12 years—are at risk of developing CHS. However, not everyone who uses marijuana, even long-term use, will develop CHS. “It tends to affect people who use cannabis at least once a week and happens more often in adults who’ve been using cannabis since their adolescent years.” The only known treatment for CHS is to stop using marijuana completely. You could have symptoms and adverse effects of CHS for a few weeks after quitting cannabis. But over time, the symptoms will disappear. Researchers are studying several treatment options, but there are no current therapies approved by the FDA.
A Sharp Increase with CHS
The CDC reported the prevalence of CHS increased sharply in the US during 2016-2022, with the largest increase occurring during the COVID-19 pandemic, and the widespread state-level marijuana legalization in the US. It is likely an underrecognized problem with both adolescents and adults. “CHS can be misdiagnosed as other gastrointestinal conditions such as cyclical vomiting syndrome.” In order to improve clinical identification of CHS, a specific ICD-10-CM diagnosis code was introduced on October 1, 2025. The CDC report examined CHS-involved emergency department (ED) trends before and after the implementation of this code.
For ED visits before the introduction of the new code, CHS was identified by using a definition that combined diagnostic codes for cyclical vomiting or nonspecific emesis (forceful vomiting without any immediate, obvious cause or distinguishing symptoms) in tandem with a cannabis-related diagnosis. Before the introduction of the new diagnosis code, CHS-involved ED visits were 3.19 per 10,000 ED visits in January of 2023 and 3.35 in September 2025. “During October 2025–May 2026, the average monthly proportion of CHS-involved ED visits was 11.97, 3.7 times as high as the monthly average (3.19) during January 2023–September 2025.”
Proportions of CHS-involved ED visits were high in younger age groups, particularly those aged 15–24 years. CHS typically occurs among those with heavy, frequent, and long-term cannabis use; previous studies have characterized CHS as a condition associated with heavy cannabis use over extended periods. However, emerging evidence indicates that symptom onset can occur much sooner than was previously estimated, including within the first year of cannabis use. Some studies have reported delays of several years from symptom onset to diagnosis, suggesting that CHS might be underrecognized, particularly early in its course. Although data remain limited, high proportions of CHS-involved ED visits among younger age groups might reflect changing patterns of cannabis use behaviors, including earlier age at initiation, increased use of high-potency THC products, evolving methods of use (e.g., vaping or dabbing), changing perceptions of risk, or increased frequency of use among younger populations.
Introducing a specific diagnosis code for CHS in October 2025 improved the public health recognition of the new disorder. Before its implementations, many cases of CHS were likely not identified as a cannabis-specific problem, but misclassified as cyclical vomiting syndrome. The new code enables more consistent documentation and may facilitate clinical recognition, “improving the ability to monitor the public health impact of CHS, detect changes in incidence, and understand risk factors across populations.” Psychology Today noted that historically, there has been a controversy as to whether CHS was an actual condition. It was also thought to only affect heavy cannabis users, those who used daily over the course of years.
But, according to the CDC report, emerging evidence suggests symptoms can occur much sooner than previously estimated; potentially even within the first year of cannabis use. Moreover, younger people—especially those ages 15 to 24, and females—accounted for a disproportionate share of CHS-involved ER visits.
Scromiting episodes can occur within 24 hours of cannabis use. Medical complications can include erosion of tooth enamel, acute kidney injury, electrolyte imbalances, dehydration, weight loss, seizures and kidney failure. The form of marijuana consumed may influence how quickly symptoms appear. Vaping or dapping appears to increase the risk of CHS. A study published in Cannabis & Cannabinoid Research found that individuals who used cannabis by vaping developed chronic vomiting faster than through smoking or edibles.
The CDC’s findings shine a bright light on the risks, prevalence, and serious health effects of cannabis hyperemesis syndrome/scromiting, especially for young people. As the adverse consequences of expanding cannabis use become more clear, severe, and prevalent, the need to strengthen awareness and education efforts and resources becomes an increasingly essential public health priority.
Vaping and CHS
In March of 2026 researchers published “Cannabinoid Hyperemesis Syndrome-A Survey-Based Approach to Understanding Symptoms and Cannabis Use Patterns” in the journal Cannabis & Cannabinoid Research. The authors sought to improve our understanding of CHS by examining patterns of cannabis use and identifying symptom profiles of individuals suspected or diagnosed with CHS. A total of 1,134 participants were included in the final analysis. Most respondents reported either smoking cannabis flower or using vape cartridges.
The overwhelming majority of respondents (96.5%) used cannabis products at least daily, with approximately half (45%) using them six or more times per day around the time they developed CHS symptoms. Most of the respondents (61.9%) sourced cannabis from licensed dispensaries. The duration of cannabis use prior to symptom onset varied widely among participants, with nearly two-thirds (65.4%) reportedly used for more than 3 years before symptom development. During the prodromal (early) phase, symptoms clustered in the morning (63.1%) and the predominant complaints were nausea and stomach pain. Women reported more frequent and prolonged symptoms than men.
SFGATE said the researchers found that people using vape cartridges developed CHS much faster than those who smoked marijuana or used edibles. One of the study’s authors thought their findings were a public health concern. “According to our recent study findings, those who utilize vapes alone are hitting it more often throughout the day and developing CHS symptoms sooner than those who smoke—by YEARS.” Yet, the study’s lead author cautioned their results do not prove vaping cannabis is more dangerous than smoking.
“This is just an association that we saw. We certainly can’t say anything definitive. . . It’s just something we noticed that people who exclusively vaped developed CHS in a shorter timeline.” However, the strong association between heavy daily cannabis use, including THC-rich vape cartridges, provided strong evidence that THC was causing CHS. The lead author of the study suggested CHS was likely caused by changes to the body’s endocannabinoid system, resulting in someone developing CHS even after safely consuming cannabis for years.
SFGATE said many cannabis users deny that THC could be the cause of nausea, and blame vomiting on cannabis that was contaminated with pesticides or other toxins. Complicating this issue is that some cannabis products have been shown to help treat nausea. Trump’s Executive Order 14370 mentioned there was scientific support for using cannabis to treat nausea and vomiting. But the study here included people who bought their cannabis from a variety of sources, including legal stores and unlicensed sources. This variety of sources refutes the idea that CHS is caused by contaminated cannabis.
Unfavorable Mental Health Outcomes
Not surprisingly, in addition to CHS, research indicates there is an increased risk of unfavorable mental health outcomes, particularly for psychosis or schizophrenia and high-THC cannabis. As the US has progressively moved towards legalizing recreational marijuana since the time of the Cheech and Chong movie, Up in Smoke in 1978, we’ve seen the THC content of cannabis flower increase from an average of 3% to around 15% today. Axios reported the average potency of cannabis seized by the DEA rose from 5% in the 1990s to 16.1% in 2022. Some strains may test above 20%. Concentrates like wax, shatter or vape oils can be between 60% and 90% THC.
Robin Murray, a Professor of Psychiatric Research at King’s College, London, has remarked, “Cannabis is not as safe as was once thought.” In an editorial for the BMJ, he said: “The USA and Canada have embarked on a major pharmaceutical experiment with the brains of their youth, and we should wait and see the outcome of the experiment.” Murray is a leading expert on cannabis and psychosis and supervised the research illustrated in a video of a reporter who participated in an “Intravenous THC & CBD Experiment.” For more information on cannabis and mental health, particularly psychosis, see “Marijuana and Psychiatric Illness.”
So, if marijuana is eventually reclassified as a Schedule III drug, there could be a surge of research into its supposed medical and mental health benefits. But I’m willing to bet concurrent research illuminating the adverse medical and psychiatric effects of cannabis will over shadow it. However, it may be too late to stop the movement towards national legalization of recreational marijuana.
