Doctors in Colorado say their Canadian colleagues should expect an increase in emergency room visits after cannabis becomes legal for recreational use on Oct. 17.

“Many people have demonstrated that emergency department visits have increased in areas where cannabis policy has been liberalized,” Dr. Andrew Monte, an associate professor of emergency medicine at the University of Colorado Hospital, told CTV News.

In Jan. 2014, Colorado became the first U.S. state to sell recreational marijuana. In the nearly five years since then, researchers have reported an uptick in cannabis-related hospital visits, often because inexperienced users consume too much, too quickly.

“We absolutely had a rapid increase and a pretty sharp spike,” Monte, who has been tracking the health effects of legalized cannabis in Colorado, explained.


The spike, Monte says, has largely been psychiatric, with the state’s hospitals seeing a fivefold increase in cannabis-triggered mental health issues such as anxiety, depression and even acute psychosis.

“That surprised me because many patients actually believe that cannabis use is actually helping their depression and anxiety,” Monte said. “The medical literature does not support that at this juncture… Now, (cannabis) may make people feel better on the short term right after they smoke, but the problem is it’s like a stair step (and) they end up actually at a higher level of anxiety overall.”

Doctors in Colorado have also seen nearly double the number of cases of severe vomiting amongst heavy cannabis users. This poorly understood condition, which is known as Cannabinoid Hyperemesis Syndrome, is best treated by abstaining from cannabis use.

“That is a cyclic vomiting syndrome,” Monte explained. “So multiple times a day, every single day.”

An increased number of children have been hospitalized because of cannabis too, often due to consuming edible products such as cannabis-infused cookies and candies. Symptoms can range from simple sleepiness to being comatose in the most extreme cases.

“The typically age for the accidental or unintentional exposures are typically the young toddler age, so one, two years of age,” Dr. Sam Wang, an emergency physician and assistant professor of pediatrics at the Children's Hospital Colorado, told CTV News. “Obviously, a young child is going to be attracted to these (edible) products and they can have high amounts of THC and get these kids into trouble.”

Edibles, moreover, are the main cause of cannabis-related emergency room visits by adults, researchers say, with inexperienced users often consuming too much because they do not realize that it can take hours before effects are felt. Doctors call this “stacking.”

“So they'll take one, they don't get the effect they’re hoping for, they take another one,” Monte said. “They still haven’t had the effect of the first dose so they take another, and then all the sudden they’ve got three times the dose that they should of, which ultimately ends up an adverse drug event and them coming to the emergency department.”

Colorado has also experiences an increase in tourists visiting its emergency rooms after travelling to the state to sample cannabis. The state has launched a safe-use campaign to avert these types of emergency cases, but even with such public campaigns, emergency room visits continue to rise.


Because health care is privatized in the U.S., hospitals have been able to cope (and profit from) an increase in cannabis-related visits. But in Canada, where our publicly-funded hospitals are already operating at near 100 per cent capacity, the effects on the health-care system could be more profound.

“As emergency physicians, we’re in the worst-case scenario business,” Dr. Atul Kapur, an Ottawa-based emergency physician who also co-chairs the Canadian Association of Emergency Physicians’ (CAEP) public affairs committee, told CTV News.

“So, we’re hoping for the best but we’re planning for whatever happens,” Kapur added. “It is a real concern in the emergency departments and in the hospitals overall.”

Based on experiences in the U.S., doctors in Canada are expecting a 67-per-cent rise in cannabis-related emergency room visits -- from six per 1,000 to 10 per 1,000 -- after legalization goes into effect on Oct. 17. Although that is by no means a huge increase, it could be problematic at a time of year when the flu season puts a strain on our already busy emergency rooms.

Kapur notes that Canada has already “seen increases in marijuana-related emergency problems over the last few years.”

“We’ve heard promises that any increase (in) revenue is going to be directed towards helping those who have got problems because of increased marijuana use,” Kapur added. “Unfortunately we haven’t seen anything concrete yet. We’re still waiting.”


Because cannabis-infused edible products have been the biggest source of toxicity for both adults and children in Colorado, some emergency room doctors there believe that they should not be sold for recreational use.

“When we actually standardized for product sales, we actually saw 269 times the rate of (emergency room) visits associated with cannabis edibles when compared to inhaled products,” Monte said. “The three deaths that are attributable to cannabis here in the state have all involved edible products and that’s scary to me and that’s why I think edibles in the recreational marketplace don’t belong.”

Such products will not be available in Canada on Oct. 17, though the federal government has suggested that they could be sold in about a year’s time.

“We’re waiting to see what happens,” Kapur said. “The federal government hasn’t released regulation on edibles yet, but that is a great source of the problem down in the States, especially with children getting into it and we’re very concerned about that.”

With a report from CTV Medical Correspondent Avis Favaro and producer Elizabeth St. Philip