CNN- Daniel Carcillo wanted two things in life: to play hockey and to be a father.

The Canadian started ice skating aged three and got his start in professional ice hockey as soon as he graduated high school.

By 20 he’d broken into the NHL and over the next decade would play for the Philadelphia Flyers, New York Rangers and Los Angeles Kings.

By 30, he was a two-time Stanley Cup winner with the Chicago Blackhawks and, in 2015, had retired from the sport, poised to enjoy retirement with his wife and three children, he says.

By age 31, he was suicidal.

After seven diagnosed concussions, Carcillo tells CNN that he was suffering from “dementia-like” symptoms, along with depression, anxiety and headaches, so much so that even a day out with his kids felt torturous.

“If they want to go outside on a very sunny day, and I can’t find my dark glasses to block the sun out … I would try to go outside and tough it … that would trigger a headache, and that would trigger head pressure,” Carcillo tells CNN Sport.

“Your impulse control is off,” he explained. “It would be miserable … Eventually, I would just go inside.”

Carcillo says he also suffered from insomnia and disrupted sleep and would go to bed at 4 or 5 a.m., trying to sleep as much as he could during the day so that he wasn’t around anybody or in the sun.

“It’s a very lonely place to be,” he says.

He spent over $500,000 on prescription medications and treatments at stroke rehabilitation centers, brain centers, and concussion centers, as well as holistic therapies, and worried that he was a “burden in people’s lives.”

Then in a “last-ditch effort” to try and alleviate his symptoms, he says he took a dose of psilocybin – the main psychoactive ingredient in magic mushrooms – in Denver, which became the first US city to decriminalize hallucinogenic mushrooms.

“And I woke up the next day and I describe it as feeling the way I should,” said Carcillo. “I felt like, for the first time in a very, very long time, I had a zest for life. All I wanted to do was get on FaceTime and call my wife and call my kids and get back home.”

Sporting potential

Carcillo isn’t the only athlete – former or current – openly talking about using psychedelics to treat various conditions.

Psychedelics, described by Harvard Health as a “loosely grouped class of drugs that are able to induce altered thoughts and sensory perceptions” – including acid (LSD), mushrooms (psilocybin), ecstasy (MDMA), ayahuasca, DMT (dimethyltryptamine) and ketamine – have a checkered legal history.

In 2022, residents in Colorado joined Oregon in voting to legalize psilocybin.

Small clinical trials have shown that one or two doses of psilocybin, given in a therapeutic setting, can make dramatic and long-lasting changes in people suffering from treatment-resistant major depressive disorder, though scientists are still exploring the how and the why behind the connection between psychedelics and improved mental health.

Last year, Australia became the first country in the world to legalize clinical prescribing of MDMA, more commonly known as ecstasy, and psilocybin for certain mental health disorders.

But experts also warn that taking psilocybin and other hallucinogens comes with potential health risks, such as psychosis or other longer-term mental health issues in some, as well as physical effects such as raised blood pressure and heart rate abnormalities.

NFL quarterback Aaron Rodgers has continued to advocate for the legalization of some psychedelics, claiming last year that ayahuasca – a drink made from Amazonian plants that contain a psychoactive ingredient – helped to improve his performance on the football field.

“Is it not ironic that the things that actually expand your mind are illegal and the things that keep you in the lower chakras [energy points in the body] and dumb you down have been legal for centuries?” Rodgers said last year at a psychedelics conference in Denver.

Former pro boxer Mike Tyson has said that magic mushrooms changed his life, and UFC President Dana White in 2021 said the organization was “diving in” to research on psychedelic drugs as a therapy for fighters’ brain health.

Elite athletes experience mental health disorder symptoms and psychological distress at similar, if not higher, rates to the general population, researchers pointed out in a study published in the Journal of Applied Sport Psychology.

Courtney Walton, an academic fellow in psychology at Melbourne School of Psychological Sciences, told CNN that many athletes fear seeking mental health support, believing “they may be perceived as somehow less competent or resilient than their peers and competitors, which can be made worse by upcoming team or coaching selection pressures.

He added that “athletes might overlook or normalize symptoms of mental ill-health, as rationalized within a highly pressurized environment.”

Walton explained it is “likely that psychedelic-assisted psychotherapy has particular appeal to athletes given the more time-constrained nature of treatment.”

He added that “psychedelics do not typically appear to have significant physical side effects” which could appeal to athletes who have experienced or heard of negative experiences with psychiatric medicine affecting performance.

UFC Senior Vice President of Athlete Health and Performance Jeff Novitzky said in May 2021 that White gave him a “directive” to explore psychedelic research to see if it helps with addiction and mental-health problems, as well as traumatic brain injury.

Novitzky told CNN the UFC is interested in any therapies that have the potential to improve brain health, and that the organization has had discussions with experts from institutions like Johns Hopkins and the University of Miami about the potential application of psychedelics, though nothing has progressed past preliminary conversations at this stage.

“All the scientists that we’ve talked to said, ‘Hey, there’s a potential real benefit here to treat brain injuries and for brain health,’” said Novitzky, adding there is still negative stigma associated with some drugs, citing cannabis.

Three years ago, the UFC changed its anti-doping policy so that ”positive tests over the threshold and decision limit for carboxy-THC, the psychoactive ingredient in cannabis, will no longer be considered a violation of the UFC Anti-Doping Policy, unless additional evidence exists that an athlete used it intentionally for performance-enhancing purposes,” according to a news release posted on their site in 2021.

Researchers in the field say that psychedelics are shown to work when treating some mental health conditions.

“The case is compelling when you look at this as a psychological treatment, where you might be treating depression or more or less any other psychiatric disorder with a couple of exceptions,” Robin Carhart-Harris, Ralph Metzner Distinguished Professor of Neurology and Psychiatry at University of California San Francisco, told CNN Sport.

However, when it comes to treating brain injuries with psychedelics, “the truth of the matter is that there’s a lot that’s not known,” Carhart-Harris, former head of the Centre for Psychedelic Research at Imperial College London, added.

“There is an increasing amount of evidence to suggest that psychedelics promote aspects of brain growth,” he says, adding: “We need that smoking gun: a clear demonstration of this in an injured brain where we see regeneration afterwards. And at the moment, we’re close, but no cigar,” he said.

Carhart-Harris warned that psychedelics are “potent” and have the power to make people “psychologically agitated” when they are already psychologically vulnerable.

“People think they can just turn on, tune in and cure themselves. And it’s not that simple,” he added, explaining that if psychedelics aren’t paired with psychological support or psychotherapy they can be “harmful.”

James Rucker, a consultant psychiatrist and a senior clinical lecturer at King’s College London, said that evidence has shown that psilocybin can be used to manage treatment-resistant depression but warns that psychedelics are “very hyped,” with people having “huge expectations” as to their impacts.

“With great expectation comes great capacity for disappointment,” Rucker said, adding that while this can often be dealt with positively in a medical setting, “if you’re on your own, if you’re in a crappy situation, that can make things worse.”

Carcillo’s story

Following the head injuries sustained during his hockey career, the now 39-year-old Carcillo began struggling with depression and anxiety and was self-medicating with alcohol, painkillers, muscle relaxers and sleep aids.

Suffering from slurred speech, weight loss and memory issues, he became “very disinterested in life” after the birth of his first child.

“I just didn’t care, which was very weird that I felt that disconnected because I’ve always wanted to be a dad. It was kind of scary,” he said.

Carcillo was one of several hundred players who accused the NHL of failing to prevent hockey-related head trauma and hiding the dangers. The lawsuit was settled in 2018, with the league not accepting liability for the claims.

In 2019, by now a father of three, Carcillo found himself in a “very, very dark, dark place. I didn’t think I had a way out.”

He began reading medical papers and found a psilocybin study from the Imperial College of London, where researchers found “the psychedelic compound may effectively reset the activity of key brain circuits known to play a role in depression.”

That’s when Carcillo traveled to a decriminalized city and “partook in a really large dose ceremony,” taking the psilocybin recreationally and not part of a clinical study.

Later, he founded Wesana Health, a biotechnology company which focuses on developing psychedelic medicine for mental health, the most recent being a CBD and psilocybin-based drug.

The company met with the US Food and Drug Administration in March 2022 and has been working through the early drug development process, and recently sold the program to NASDAQ-listed Lucy Scientific Discovery. He is no longer involved in the company.

He told CNN that he regularly microdoses psilocybin, as well as partaking in larger doses from time to time.

“I continue to monitor my health with regular brain scans and blood work, and adjust my dosing schedule of medicinal mushrooms accordingly,” he added.

Carcillo is clear that his current well-being isn’t solely due to psilocybin, saying he exercises regularly, is careful to manage his sleep as well as sugar and alcohol intake, and makes sure to get out and about in the sunshine.

Ceremonies with mushrooms, LSD, ayahuasca and toad

Former US rugby player Anna Symonds says she was diagnosed with TBI about 10 years ago and has to take several different hormones that her body – notably her pituitary gland –  is not making as a result of the head injuries.

Now retired from rugby, Symonds tells CNN Sport she has started to feel the effects of injuries to her body and head from years of participating in contact sports like rugby, soccer and mixed martial arts as well as being involved in two car crashes.

“I was physically not feeling well. In addition to my pituitary issues, I have an autoimmune issue with my thyroid,” she explains, adding that she also experiences headaches, memory issues, depression and anxiety.

She began using psychedelics to help with this, taking part in “macrodose-level journeys or ceremonies with mushrooms, LSD, ayahuasca and Toad.”

Also known as the Colorado River toad or the Sonoran Desert toad, the amphibian releases a venom called 5-MeO-DMT, which is known to have hallucinogenic effects, according to the Addiction Center website, which also warns of its dangers.

Since her retirement as a professional athlete, Symonds explains that she uses psychedelic drugs for clarity, though not under the direction of a doctor.

She adds that using cannabis for pain relief or using psilocybin does not necessarily elicit dramatic changes compared with other plant-based psychedelics.

“It’s this groove, it’s the spiral that you can’t seem to get out of, and it just almost reinforces itself. The experience of plant medicines is for me, like psychedelics, is that it lifts you out of the groove.”

Caution urged

Guidance from the US National Institutes of Health (NIH) states that the effects of psychedelic and dissociative drugs may be difficult to predict and depend on many factors.

Short-term side effects from the drugs can include headaches, abdominal pain, nausea or vomiting, high blood pressure, rapid heartbeat, trembling and diarrhea, the NIH notes, though it adds that reported cases of side-effects likely represent only a very small number of users.

Rucker tells CNN: “I feel I need to draw a clear line between what we do in our clinical trials – which is safe and contained – and recreational use, which can be therapeutic, but can be dangerous, and is, by definition, experimental.”

Rucker added that it’s important not to overhype the effects of substances like psilocybin for mental health conditions, as other treatments including antidepressants, lithium, cognitive behavior therapy, meditation and electroconvulsive therapy (ECT) can have similar effects.

“They’re special, they’re unique, but they’re not that special,” says Rucker. “They’re just drugs. And we need to work out where they sit and not be too gung-ho with them.”

Education needed

Rucker says that more education is needed around psychedelics, as regardless of a country’s laws, people will continue to take these substances.

“We need to make sure that people are doing their homework and not treating this as a recreational drug like any other but actually treating it with the respect it deserves,” he tells CNN.

Carhart-Harris explains “all aspects of mental illness can fall on anyone, whether they be a sportsperson or not.”

Still, he adds that psychedelics could be harnessed to enhance sporting performance, through enhancing discipline or helping people to process pressure or failure.

“Then you have the sort of positive psychology side, where you could use, for example, low doses of psychedelics to enhance some of the training, say, getting more into one’s body, more easily entering flow states, intense focus, not being too heady and cerebral. I think there is real potential for using psychedelics in a sort of skillful way,” Carhart-Harris says.

Symonds adds: “Medicines don’t just have to be a treatment for when you’re sick or ill or broken, they can be something that you take to keep you well or to enhance your wellness, your wellbeing, your spirituality.”

Editor’s Note: If you or someone you know might be at risk of suicide, here are ways to help.

If you live in the US and are having suicidal thoughts, call the National Suicide Prevention Lifeline at 800-273-8255 (800-273-TALK) for free and confidential support. It’s open 24 hours a day, seven days a week.

For crisis support in Spanish, call 888-628-9454.

TrevorLifeline, a suicide prevention counseling service for the LGBTQ community, can be reached at 866-488-7386.

Befrienders Worldwide connects users to the nearest emotional support center for the part of the world they live in.

CNN’s George Ramsay contributed reporting.