SEATTLE — Before reaching for the weed on 4/20, there’s a recent study on cannabis use to consider. 

Since recreational marijuana became legal in the state of Washington in 2012, health care providers have been increasingly noticing adverse effects of taking the drug, according to a new study from the University of Washington. 

Dr. Bia Carlini is a professor at UW Medicine’s psychiatry department, where she directs the Cannabis Education and Research Program.

“We basically are trying to give a face to in Washington State to what the consequences of having cannabis so much more available and so much stronger,” Carlini said. “It seems like some people will claim they are having way more fun, which nobody’s here to dispute, but we also want to see what is happening in terms of burden.”

She’s referring to the burden on health care providers who are noticing something concerning. Her findings on the health consequences of cannabis use were recently published in the Substance Use and Addiction Journal, which found some eye-opening results.

In a survey of 388 doctors and clinicians in Washington state:

• 35% reported seeing patients about cannabis-related problems, at least two to three times a month
• 70% of the clinicians reported treating patients who experienced severe vomiting and nausea related to cannabis use
• 53% said they saw patients with psychoses and hallucinations linked to cannabis, with many observing this as the most serious adverse effect

“Interesting that the three things they are seeing the most are exactly the things they weren’t commonly seen before legalization. Ten years ago, nobody was talking that much about terrible cycles of vomiting and nausea and pain,” Carlini said.

In Washington, recreational pot became legal in 2012 and retail sales began in 2014. Since then, Carlini notes, the risks associated with cannabis use are increasing due to higher potency and more frequent use.

“Cannabis has changed so much. From a plant that was used as a joint, you have now these very powerful concentrates where you went to, you know, 70 percent of THC,” Carlini said.

Dr. Carlini hopes her research leads to more awareness and training for health care providers to treat cannabis-related health issues, and hopes it advocates for more research into medication to treat such conditions.

“We didn’t do any wrong in legalizing cannabis, but we did not perceive some of the effects that would come down the road of what happened,” Carlini said.