A widely cited claim that about 2.8 million Americans suffer cannabis hyperemesis syndrome each year traces to a debunked 2018 study, not solid national evidence.
That estimate spread through major outlets including The Washington Post and The New York Times, which used it to frame CHS as a large-scale consequence of heavy marijuana use.
The critique says the paper relied on a poorly sampled study group and an overly broad definition of CHS, turning a rarely diagnosed condition into an implausibly common one.
The dispute matters because the figure has shaped coverage and arguments for tighter marijuana regulation, despite weak evidence behind the headline number.