This is part three in a five-part series. Click here to read the other four parts.
San Diego has long been a favorite spot for tourists who come for its surfing, beaches and parks. But for the past couple of years, tourists have also been coming for something else.
And that has contributed to a bump in emergency room visits, said Dr. Richard Clark, an emergency physician and director of medical toxicology at UC San Diego.
"It's much easier for people to get in general, and so tourists or visitors to California will often want to try it," he said. "And they won't have the experience that many local users have and may accidentally use too much."
That's particularly true with edible marijuana like gummies or brownies that take longer to have an effect, which leads some people to eat too much. Of course, Clark said, it’s not just tourists who make this mistake—he sees plenty of locals too.
"They'll develop what looks like a bit of an anxiety reaction, and their heart rate will be high, they'll say I don't feel right, they may be dizzy and in a lot of distress," he said.
Two of the biggest concerns, when voters legalized recreational marijuana in 2016, were that overdoses would crowd emergency rooms and young people—who are particularly vulnerable to cannabis addiction—would use more. In the first two years of recreational sales, data shows emergency room visits and youth addiction are increasing, but medical experts say it's too early to draw any hard conclusions about legalization's impact on public health.
Clark's experience that emergency room visits have increased for marijuana overdoses is born out in data from the California Office of Statewide Health Planning and Development. It shows since marijuana was legalized, visits for cannabis poisoning have gone up by 35 percent in San Diego County, from 606 in 2016 to 820 last year. Across California, visits have gone up by almost 49 percent, to just under 8,000 last year.
However, Clark and other doctors don’t see this as a public health crisis. People who come into the ER after having smoked or eaten too much pot don't usually need medical treatment.
"A lot of times if we just watch them in a nice, calm environment, they're better in an hour or two," he said.
Yet, while the risk of long-lasting effects from a pot overdose might be overstated, the risk of becoming addicted is understated, said Dr. Kai MacDonald, the medical director at Lasting Recovery, a San Diego addiction treatment center.
"The myth in the world is there's no such thing as cannabis withdrawal, you can just stop smoking," he said. "But when you take people who use cannabis daily and lock them in a hotel and ask them how they feel, they have withdrawal symptoms."
Not only is cannabis use disorder — also called cannabis addiction — a real condition, but one research study showed that in states where marijuana is legal, addiction rose 25 percent among 12- to 17-year olds, the group most vulnerable to long-term cannabis addiction.
Also, there is a growing body of research showing a link between marijuana and psychiatric disorders in teenagers, according to a review of studies by the National Institute on Drug Abuse. For example, one study earlier this year found smoking marijuana every day could increase the chances of developing psychosis by nearly five times.
"After recreational marijuana use is legalized, addiction goes up in a very vulnerable subgroup," MacDonald said. "Cannabis legalization means there is more out there."
Data from San Diego County's Health and Human Services Agency shows marijuana was the drug of choice for 82 percent of young people who were treated for addictions last year in county-funded programs. Before legalization, that number was also very high, at 80 percent.
The numbers are significantly different among adults seeking county-funded treatment. Marijuana is low on the list of the most popular drug of choice, at 16 percent, behind alcohol, heroin and meth.
Those other drugs—including alcohol—are far more harmful to the body, said Dallin Young, the political director for the Association of Cannabis Professionals. As for the rising ER visits, Young said they could be going up because people feel safe to call the hospital when they're not feeling well.
"I do want to highlight the fact that in any of those increased ER visits, there have been zero fatalities, and this is true throughout the entire country," he said.
The law should allow for places where people can go to safely ingest marijuana--where they can get guidance so they don't take too much, Young said.
That matches advice from Clark, the ER doctor.
"If you're going to try an edible, you need to start at a lower dose, so you know what your reaction is going to be, or how it makes you feel," Clark said.
And then wait before trying more, he said. But as long as San Diego continues to be a top tourist destination, Clark expects some people could spend part of their vacation in the ER, and not just for surfing injuries.