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Proponents, opponents offer different takes on marijuana and health

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In Leili Fatehi’s view, outlawing marijuana hasn’t worked.

“Prohibition has been a massive failure in every regard,” said Fatehi, representing a group called Minnesotans for Responsible Marijuana Regulation. “It has not accomplished any of its intended goals. It hasn’t protected public safety. It hasn’t protected the public health. It hasn’t kept it out of the hands of adolescents.”

But legalizing recreational marijuana in Minnesota would make the situation worse, not better, said Kim Bemis, chairman of the Minnesota chapter of Smart Approaches to Minnesota, which argues that current science doesn’t support legalization.

“Nobody is doing this right yet,” Bemis said. “Yes, it may come to pass over the course of time that marijuana is legalized but … let’s let some other states figure it out first.”

Gov. Tim WalzAlthough Bemis disagrees when this is suggested, the tide may be running against him. Ten states have legalized recreational marijuana, as has Canada. Almost all of the Democratic presidential candidates, including Sen. Amy Klobuchar of Minnesota, have come out in favor of legalization. So has Minnesota Gov. Tim Walz. State Sens. Melisa Franzen, DFL-Edina, and Scott Jensen, R-Chaska, — who is a medical doctor — along with Rep. Mike Freiberg, DFL-Golden Valley, are co-sponsors of a bill that would legalize recreational marijuana in the state by 2020, although Senate Majority Leader Paul Gazelka, R-Nisswa, has said it won’t pass.

Bemis noted that eight states — most recently Hawaii — have turned down legalization.

Nonetheless, it’s easy to see where momentum comes from. Successive polls last October showed 62 percent (Pew Research Center) and 67 percent (Gallup) of Americans favoring legalization.

But could there be unintended consequences when it comes to public health?

It depends on how legalization is handled, Walz said during a stop in Duluth last week.

“I don’t make light of this, that this is harmless, that nothing can come out of this,” he said. “What I simply think, like many things, whether it be alcohol, whether it be gambling, that it can be done in a controlled envionment, you can educate people on it, you can have adults make choices. Are some going to make bad choices? Yes, they are. And then I think you have things in place to try to mitigate the damage that causes.”

But in the case of recreational marijuana, what damage can it cause?

The evidence is contradictory to a frustrating degree. Even where there’s agreement, there are different views on whether legalization would lessen or exacerbate the problem. What follows is a summary of views on three issues: mental health, brain development in adolescents and impaired driving.


A “meaningful portion” of the population can use cannabis occasionally and have positive experiences with no major medical or psychotic consequences, said Dr. David Baldes, a psychiatrist for St. Luke’s Psychiatry Associates.

David BaldesBut some people risk such consequences, Baldes added. “The people who I see at the highest risk are people (for whom) schizophrenia runs in their family, or bipolar illness runs in their family.”

Marijuana use plays a role in about half of the patients he sees, Baldes said.

A 2015 study printed in the British medical journal Lancet by researchers from Kings College in London concluded that individuals who had used high-potency cannabis were about three times more likely to develop psychotic disorders as those who had used no cannabis.

But Fatehi suggested that other substances — such as lead in water, chemicals in plastic and alcoholic beverages — are much more likely to have psychotic repercussions.

“There is no compelling scientific evidence that marijuana causes any mental disorders in otherwise healthy individuals,” she said.   


There’s widespread agreement that cannabis use has a detrimental effect on development of the adolescent brain.

“There’s good evidence that … cannabis use in adolescence clearly, reliably, predictably causes brain damage,” Baldes said.

The area of the brain that’s affected is responsible for reasoning, judgment, self-control, discernment, higher-level cognitive function, he said.

Melisa FranzenThat’s why recreational marijuana would be legal only for those 21 and older, Franzen said. That has proven relatively effective elsewhere, she said.

“The research I’m reading shows … once you legalized cannabis in Colorado the use has declined (among adolescents), partly because now you’re policing it more, you’re regulating it more and people have the information in front of them,” Franzen said.

Bemis is skeptical.

“How did that work with alcohol and tobacco?” he said. “It just doesn’t work with alcohol and tobacco. I could find all the cigarettes I wanted when I was 13, 14. Increased availability does equal increased consumption.”

Although he realizes it’s unlikely, Baldes said he’d prefer an age limit of 25 or below. The brain isn’t fully developed — particularly in males — until age 28 or 29, he said.

“If you were looking purely from a biological standpoint of when is the brain best equipped to maybe be able to tolerate cannabis, you’d have a legalization age of 28 or something,” he said. “Which of course is not something that’s practical.”


As with so many things about legalized marijuana, there’s contradictory evidence.

Bemis cites a doubling of traffic fatalities in which marijuana was present following legalization in Colorado. “Yes, there may be other drugs or alcohol involved, but it’s showing the presence of it there.”

Fatehi looks at the data differently.  

“I would say that the scales have tipped in the direction of showing that there has not been an increase in vehicle crashes and injury as a result of marijuana legalization,” she said.

Colorado, where recreational marijuana was legalized in 2014, provides the most data for the rest of the nation. Since legalization, traffic fatalities have spiked by about 30 percent, said Sam Cole, traffic safety communications manager for the Colorado Department of Transportation. But traffic fatalities are up everywhere, in states where marijuana is legal and in states where it’s not, he said.

“We see no indications that the rise in traffic fatalities is due to legalization of marijuana,” Cole said. “We’re seeing a lot of spikes in other things, such as distracted driving, texting … alcohol.’

But state Sen. Erik Simonson, DFL-Duluth, wants more information.

“I am concerned about the impact on driving, how law enforcement would measure levels of influence, and how that would interact with our current motor vehicle operation laws,” he wrote in an email.

Walz is sympathetic with that concern, he said.

“People say, ‘Well what about driving and doing this?’,” Walz related. “Of course, that’s dangerous … just like drinking and driving is. I simply am not advocating for another vice, I’m arguing for adults to make an informed decision, with parameters put in place.”  


Erik SimonsonSimonson is among those who’s waiting for more evidence to come in before reaching a conclusion.

“I am not there yet — in terms of supporting full legalization,” he wrote. “I was here in the Legislature for the debate and discussion on medical marijuana, and that took some pretty deep dives and research to get to a point where I ultimately supported that.”

In addition to questions about traffic safety, Simonson wrote that he’s concerned about marijuana being a “gateway” to more harmful drugs.

“I know advocates will say otherwise, but I have seen it too many times to believe any argument that it is, in fact, harmless,” Simonson wrote.

Though opposed to legalization, Bemis said he could support decriminalization.

“In Minnesota, because of passing of a law in 1976 making it a petty misdemeanor, we don’t have many of the same issues that other states do have,” he said. “Yet it is a cause for frisking and searching and stopping and other things. Let’s figure out a way to not let that happen.”

Fatehi, Franzen and Walz all cited discriminatory enforcement of current marijuana laws as among their concerns.

“There are some serious racial disparities in the criminal justice system that are caused by it,” the governor said.

Franzen said the legislation is a work in progress as input from concerned groups is sought.

“We’ll get better data,” she said. “This bill is not intended to be effective until 2020, so I think by then we would probably have better data to figure out how to best regulate it.”

Too fast, too soon?

“I’m not sure that I would say it would be moving too fast,” Baldes said. “That ultimately would be a political thing. If the culture supports it, then our job on the front lines of medicine is to take care of individuals however they’re impacted.”