DENVER – Tucker Max tried to drown his childhood sadness in booze and sex. That didn’t work, although it netted him a best-selling book and a movie based on his story. As he got older, he tried working out, and got fit but still felt lousy. He also tried business, co-founding publishing house Scribe Media, but his mind still struggled.

It wasn’t until he turned to MDMA and psilocybin – “magic mushrooms” – that he finally found something he believes altered his brain chemistry for the better. After taking a large dose of mushrooms at a spiritual retreat in South America, Max had what he describes as a life-changing mental journey akin to a near-death experience. Like many other mushroom users, Max, 43, claims the substance opened his mind to a new way of seeing the world, allowing him to make permanent changes to his brain.

“Dude, I went to the other side, man. I went to another universe. I had a whole re-evolution. It was crazy. It was a true ego death,” said Max, the Austin-based author of the infamous sex-and-booze romp book “I Hope They Serve Beer In Hell.” “You realize you are a speck of energy in this massive system. You realize you’re completely inconsequential and that means you can look at yourself objectively.”

Psychedelics first gained widespread popularity in the 1960s and 1970s, but went underground after being classified a Schedule 1 controlled substance by the federal government in 1970. Today, their potential for use as a mental-health treatment for PTSD, anxiety and depression is gaining new attention after Denver and Oakland, California, decriminalized their possession and voters in Oregon and California in 2020 may be asked to approve statewide measures. Mushroom advocates see many parallels between their efforts and medical marijuana legalization that has passed in 33 states and the District of Columbia.

Medical experts say mushrooms can pose a danger to a small number of people with serious mental health issues, especially in large doses, but note they aren't considered physically dangerous or addictive. Mushroom enthusiasts say any dangers they might pose are far outweighed by the benefits, especially when compared to mainstream medicines like opiates. Among their supporters is Joe Rogan, the influential comedian and podcaster who urged Denver voters to support decriminalization in May.

“Modern medicine has been wholly effective in advancing the health of the population because it took a very structured, data-driven approach. And that’s a great approach. But it is also limited,” said Ronan Levy, founder of Canada-based Field Trip Ventures, a venture-capital group that hopes to open medical clinics offering psychedelic treatment. “Medical cannabis has really opened people’s minds to this.”

Denver voters passed their first-in-the-nation initiative during May's municipal elections, and Oakland's City Council adopted a similar measure in June. Mushrooms remain illegal under the federal government.

Users say mushrooms, most often eaten dried or steeped into a tea, help them see themselves and the world around them differently, allowing them to re-wire their brains in healthier ways.

"We really have a national emergency with mental health and addiction," said Kevin Matthews, founder of the Denver-based Society for Psychedelic Outreach, Reform and Education (SPORE). "It's clear we need effective alternatives that don't come with all these crazy side effects."

Best-selling author Michael Pollan helped bring psychedelics back into the nation's collective consciousness with his 2018 book, "How To Change Your Mind: What The New Science Of Psychedelics Teaches Us About Consciousness, Dying, Addiction, Depression, And Transcendence." Pollan, who is known for writing about food and agriculture, experimented with both LSD and psilocybin during his research. His book was selected as one of The New York Times Book Review’s 10 Best Books of 2018, and Pollan called the substances "astonishing gifts of nature." He also urged caution, however, and called for more research instead of widespread legalization.

Many mushroom advocates echo Pollan's sentiments: Psychedelics should be more available, but the public and authorities ought to proceed with caution by funding more research.

Matthews, 33, said he first used mushrooms with friends several years after crippling depression forced his medical discharge from the Army, where he was studying Arabic and non-traditional warfare at the United States Military Academy in West Point, New York.

"I was primed to be a special forces operator. In many ways, that's kind of what I'm doing now: dropping behind enemy lines to spread freedom," he said. "Our campaign made it very clear there's a political foundation, a political constituency, for a psychedelic renaissance."

Denver led the nation with first mushroom decriminalization approval

Matthews helped lead Denver's successful first-in-the-nation decriminalization effort, which ordered city police to make enforcement of mushroom possession laws their lowest priority. Denver police had averaged about 52 arrests a year for mushroom possession, usually in conjunction with another crime. Denver's decriminalization measure also called for the mayor to assemble a panel of law enforcement, advocates and other community leaders to examine the issues over the next several years.

"Psilocybin wasn’t a big issue before the initiative and it hasn’t been a big one after it," said Denver District Attorney Beth McCann, who sits on the panel. "We have more problems with scooters.”

McCann said she and police are primarily concerned about potential crime increases that could be associated with mushroom use, although they've not yet seen any evidence of it, and also the possible negative mental health impacts associated with potentially broader use. Mushroom advocates say the intense impacts associated with psychedelics use tend to limit their consumption.

Max, for instance, has only taken them three times, and always with guidance from experienced users. Denver's measure doesn't specify exactly how many mushrooms a person can possess before being targeted for prosecution, which police officials said may require clarification. The measure took effect upon its passage.

“What is the definition of personal use? A day? A year? A lifetime? We’re trying to find the best balance," said Denver police Commander James Henning. “If we have indication that you are selling it, then all bets are off and this law does not apply."

Experts consulted by USA TODAY said a typical individual dose of psilocybin mushrooms ranges from 1-4 grams. A single dried mushroom can weigh up to an gram, but there's no medical consensus on the appropriate amount to take. Max, who once documented exactly how drunk he was getting by carrying around a breathalyzer, took 8.5 grams his first time, and lower doses the next two. Some psychedelic enthusiasts also continuously consume low doses, known as microdoses, in an effort to reduce anxiety and improve creativity.

“There’s just not good data because quite literally it’s been illegal to do research on this," Max said. “It becomes very, very clear that these medicines – these are not drugs – are medicines that are pathways to healing the immense emotional and psychological pain that humans are in. I came out of this, I don’t want to say a different person, but with a slightly different brain.”

Doctors urge caution, but say psychedelics hold promise

Dr. Yili Huang, director of the Pain Management Center at Northwell Phelps Hospital in Sleepy Hollow, New York, said he's carefully watching how decriminalization unfolds. Huang said he's been intrigued by several small-scale studies that appeared to show terminally-ill patients can benefit from treating their anxiety and depression with mushrooms combined with therapy.

The federal government in June acknowledged that ongoing research indicates psychedelics hold promise for treating anxiety. Huang, who specializes in treating pain in cancer patients, said psychedelics like magic mushrooms work on the same brain receptors as prescription anti-depressants. He said the nation should be "very cautious" in opening the door to increased psychedelic use, but said more research could reveal opportunities to help sick people.

“Ultimately at the end of life, what’s important is not how many more days you can live, but how fulfilling they are," he said. "There’s a lot we don’t know. But there’s a potential therapeutic use of this medication in a population that we should be doing everything to help."

As with medical marijuana, psychedelic advocates have used the lack of formal studies to press their case, especially in Oakland, where they argued native people have safely used plants like these for generations. While Denver's decriminalization effort focused solely on magic mushrooms, Oakland's measure also covers substances like peyote and Ayahuasca.

Carlos Plazola, co-founder of Decriminalize Nature Oakland, said he first took mushrooms a few years ago after finding that exercise and meditation weren't enough to help change what he called negative patterns of behavior stemming from childhood trauma: “It blew my mind that something so healing could be illegal."

Oakland City Councilman Noel Gallo, who sponsored the measure, said he grew up hearing stories of his grandmother's herb garden in Mexico, a tradition his mother continued in California, albeit of the non-psychedelic kind.

"They didn't have Walgreens to go to. They used the native plants. That's how they provided healing. I grew up knowing that," Gallo said. "These are healing plants natives have used for thousands of years."

Max, the author, said he hopes to use his platform to bring psychedelics more into the mainstream after decades of prohibition. He said native cultures used them to help build community and increase self-awareness, something our modern society desperately needs. He said his use of mushrooms helped him address a childhood in which he felt abandoned and unloved, with the added benefit of reducing his anxiety about traffic, something that had long angered him.

“Three days after, we were driving and we hit traffic, and my wife tensed up and was expecting this explosion for me, but I wasn’t angry," he said. "It wasn’t like I changed my mind about traffic. It was an emotional reaction, and the energy behind it was gone. It was like the neural pathways that connected anger to traffic had melted.”