For decades, hallucinogens have been associated with technicolour dance floors, sitar-driven Beatles tunes and the controversial evangelism of Timothy Leary.

But today, drugs like LSD and MDMA are undergoing a radical transformation — from party drug to potentially revolutionary treatment tool.

Around the world, clinical trials are examining psychedelic drug therapy as a possible treatment for everything from PTSD to cigarette addiction.

Listen to our special, hour-long radio edition of The Big Trip, a special Day 6 program about the latest in psychedelic drug research.

Researchers believe psychedelic drug therapy could help treat everything from PTSD to cigarette addiction. We explore hallucinogens' transformation from party drugs to potentially revolutionary treatment tools. 54:00

To date, many of the studies have been preliminary, with small sample sizes.

But experts say MDMA and psilocybin — better known as ecstasy and the key ingredient in magic mushrooms — could be available for prescription use within the next five years.

Earlier this year, Day 6 spoke with the researchers behind the studies — and the patients who say psychedelic therapy has changed their lives.

Here are some of their stories.

The army veteran

Sergeant Jon Lubecky says MDMA-assisted psychotherapy saved his life. (Submitted by Jonathan Lubecky)

On Christmas Eve in 2006, Sergeant Jon Lubecky put a gun to his temple and pulled the trigger.

He was at peace with the decision to end his life. But the bullet never came.

Earlier that year, Lubecky had suffered a traumatic brain injury during a mortar strike on the base where he'd served in Iraq. When he returned to the United States, he was diagnosed with severe post-traumatic stress disorder.

"I'd wake up hearing explosions that weren't there," he recalled.

For eight years, Lubecky struggled with traumatic flashbacks and severe depression. None of the treatments he tried made a meaningful difference.

Then, in 2014, a medical intern handed him a cryptic note that said: "Google MDMA PTSD."

Later that year, with a trained therapist at his side, Lubecky took ecstasy for the first time.

A gloved hand holds three tablets of MDMA, more commonly known as Ecstasy. (Ross Land/Getty Images)

He was one of 24 participants in a small study in Charleston, South Carolina using MDMA-assisted psychotherapy to treat severe, treatment-resistant PTSD.

Years later, he says his PTSD symptoms are largely gone.

"It was a miracle that changed my life."

Lubecky says MDMA-assisted psychotherapy empowered him to work through his trauma. 1:00

He wasn't alone: 67 per cent of the study's participants were still PTSD-free one year after their treatment.

In 2018, researchers launched a Phase 3 clinical trial looking at MDMA-assisted psychotherapy in collaboration with Health Canada and the FDA.

If their findings line up with earlier studies, they say MDMA could be a legal prescription drug by 2021.

Other psychedelic compounds could be on a similar path — and mental health advocates aren't the only ones taking note.

George Goldsmith first became aware of the renaissance in psychedelic drug research when his son, who suffered from treatment-resistant depression, was treated with ketamine.

In 2016, Goldsmith became the co-founder of Compass Pathways, one of the first for-profit companies seeking capitalize on psychedelic drug research.

He believes psilocybin, the key ingredient in magic mushrooms, could be a legal prescription drug as early as 2022.

Lubecky believes psychedelic therapy has the potential to eradicate PTSD.

"I have really high hopes."

For more about Jon's story and the burgeoning psychedelic drug industry, check out Part One of The Big Trip.

The medical student

Octavian Mihai says psychedelic therapy helped alleviate his severe anxiety after a cancer diagnosis. (Submitted by Octavian Mihai)

Octavian Mihai was officially declared cancer-free in 2013, but his mental health was steadily getting worse.

At 21, the NYU student was terrified that the cancer might come back. After his treatment ended, those worries spiralled out of control.

"It was just crippling anxiety," he said.

Deeply concerned for his mental health, his doctor put Mihai in touch with a team of researchers at NYU who were studying psychedelic therapy as a possible treatment for anxiety in cancer patients.

Later that year, after weeks of careful preparation, Mihai put on a pair of noise-cancelling headphones and ingested a little white capsule of psilocybin.

One gram of psilocybin, the psychoactive ingredient in hallucinogenic mushrooms, is seen on a scale at New York University. (Seth Wenig/Associated Press)

He spent the next eight hours on an intense psychedelic journey — one that lifted him outside himself, and ultimately helped him overcome his fear of dying.

"I lost complete sensation of my body, and I just lifted myself to a different plane," he said.

During his eight-hour psychedelic trip, Octavian says he felt his anxiety fall away. 1:17

Researchers are still working to determine exactly how psychedelic drugs affect the mind.

According to psychologist Alison Gopnik, psilocybin decreases activity in the brain's "default mode network," which is responsible for generating our sense of self.

Gopnik believes the disruption of that network could increase our flexibility in thought, paving the way for new perspectives.

"What psilocybin seems to do is to push an adult brain back more to that state of exploration and learning," she said.

Five years later, Mihai's cancer-related anxiety has never returned.

"I've lived every day not worried about it."

For more about Octavian's story and the science behind psychedelic drug therapy, check out Part Two of The Big Trip.

The lifelong smoker

Alice O'Donnell underwent psilocybin therapy in 2012 as part of a smoking cessation trial. She never smoked again. (Submitted by Alice O'Donnell)

For nearly 40 years, cigarettes were Alice O'Donnell's constant companion.

"Cigarettes were the crutch," she said. "I finally reached the point that I could not go to sleep at night unless I knew I had at least a half a pack of cigarettes available for morning."

Over the years, she tried unsuccessfully to quit many times. But after a Pilates class left her on the verge of collapse, she decided to ditch the habit for good.

Shortly thereafter, in 2012, she enrolled in a Johns Hopkins University study using psilocybin as a tool for smoking cessation.

The drug induced powerful hallucinations, including a disturbing vision of her own damaged lungs.

According to Johns Hopkins University, 80 per cent of participants in the smoking cessation trial that Alice joined still hadn't touched a cigarette six months after their psychedelic experience. (Sebastien Bozon/Getty Images)

Alice never smoked again, but she says the drugs had other benefits as well: "Just the whole expansion of my thought processes; realizing how great the universe is out there," she said.

Researcher Matthew Johnson, who helped facilitate Alice's psychedelic therapy, likened the experience to a "crash course in meditation."

During her psychedelic therapy session, O'Donnell says she felt as though she travelled inside her own body. 0:49

Those apparent benefits lead some academics, including Jules Evans, a philosopher who studies "ecstatic experiences," to speculate that psychedelic drug therapy could eventually become a mainstream wellness practice.

Evans believes many people could benefit from access to the drugs. But he also warns that experiences like Alice's are far from inevitable.

Rather, they tend to be shaped by the expectations of researchers and therapists who serve as guides.

"The music that they play is going to affect your trip; the instructions that you get on the trip are going to guide it," Evans said. "The way that your therapist helps you to make sense of your experience will shape it as well."

Moreover, for people who are predisposed to conditions like schizophrenia, the drugs can have negative long-term consequences.

Nonetheless, O'Donnell hopes clinical psychedelic therapy will become more widely available in the future.

"I definitely think more people could benefit from it."

To learn why some researchers believe psychedelic therapy could become a mainstream wellness tool, check out Part Three of The Big Trip.

For more from Jon, Octavian, Alice and many others whose lives have been changed by psychedelic drug research, follow this link for our special, hour-long radio edition of The Big Trip.

The Big Trip was written, reported and produced by Day 6 producer Annie Bender.