New research from the Colorado School of Medicine highlights the dangers of using synthetic marijuana, marketed under such brands as “Spice” or “K2.” The study, published in the New England Journal of Medicine, reports that in the late summer of 2013, the Colorado Department of Public Health and Environment was informed of an exceptionally sizable increase in the number of ER visits related to synthetic pot in the Denver metropolitan area.

Specifically, between August 21 and September 19 of last year, 263 individuals who had consumed synthetic weed were admitted to emergency rooms, all suffering from similar symptoms including altered mental states, irregular heartbeats and seizures. Roughly ten percent of those cases were sent to intensive care for ventilator-assisted breathing.

The paper’s lead author, Andrew Monte MD, confirmed, “These substances are not benign … People may not realize how dangerous these drugs can be – up to 1,000 times stronger binding to cannabis receptors when compared to traditional marijuana.”

Synthetic pot can also affect serotonin and other receptors in the brain that can trigger delirium, seizures and strokes. Despite the clinical studies and reports in the media on the dangers of synthetic cannabis, Dr. Monte said there has been a significant rise in the use of such drugs in the past five years.

Dr. Monte predicted such outbreaks are likely to continue. “Synthetic marijuana is illegal under DEA law, but companies that make it are a step ahead with new chemicals and packaging on standby all the time.”