This week, 33 people in Brooklyn, New York who used synthetic marijuana were hospitalized after staggering and collapsing on the street.
The scene, which was live-streamed by bystander Brian Arthur on Facebook, is described as comparable to those seen in zombie movies.
"As I was walking up a block, I see anybody laying out on the floor, and everybody's just stumbling all over the place," Arthur said. "It looked like a scene out of a zombie movie."
Now a new report published in the U.S. Centers for Disease Control and Prevention's (CDC) Morbidity and Mortality Weekly Report on July 15 provides evidence that the U.S. is indeed facing a growing problem with synthetic pot abuse.
Anne Riederer, from the American College of Medical Toxicology in Arizona, and colleagues looked at data from the Toxicology Investigators Consortium (ToxIC) and found that between 2010 and 2015, toxicologists treated almost 500 cases of synthetic marijuana intoxication.
Of these patients, 61 percent said that the substance was the only drug that they had used.
Three of these died, one of whom only used synthetic pot while the other two used the substance along with other drugs.
The researchers reported that between 2010 and 2015, the annual percentage of synthetic pot cases among ToxIC sites increased in all four U.S. Census regions with the largest overall increases seen in the Northeast, which is primarily blamed on the increases at the New York City sites.
"In 2015, reported cases of synthetic cannabinoid intoxication increased at several ToxIC sites, corroborating reported upward trends in the numbers of such cases and underscoring the need for prevention," Riederer and colleagues wrote in their report.
The report said that the identified increase in synthetic pot poisoning reflects recent trends, which include a 330 percent rise in synthetic cannabinoid-related calls to poison centers during the first four months of 2015, among others.
The researchers said that the observed increase could be the result of increased use of synthetic marijuana, the emergence of more toxic and potent synthetic cannabinoid compounds and people's improved ability in detecting symptoms of synthetic pot poisoning.
Synthetic pot, which also goes by the name K2 and Spice, is meant to mimic marijuana, but it does not have the same effects as those of weed, experts said.
The compounds that are present in Spice, for instance, can be between two to 100 times more potent compared with THC, the main psychoactive ingredient present in marijuana.
Because the compounds found in these drugs constantly change, the effects on the users can be unpredictable. Synthetic pot overdoses have been linked to delirium, heart and kidney damage, coma and even death.