When her best friend announced she planned to fly to the Amazon to cure her lifelong anxiety with ayahuasca, a vile-tasting brew renowned for inducing titanic hallucinations, Rosalind Watts begged her not to go. As a clinical psychologist, she knew that conventional psychiatric medications were by no means a panacea. But the idea of her friend disappearing into the jungle to swallow a reality-warping concoction under the supervision of indigenous shamans didn’t just terrify her: It threatened to demolish the bedrock of assumptions that underpinned her career.

“I remember putting the phone down and just being really, really worried about her,” says Watts, 36, speaking on her houseboat on a London canal. Then a by-the-book talk therapist working for Britain’s National Health Service, Watts is now one of the pioneers in a new generation of clinicians, neuroscientists and psychiatrists fomenting a revolution in mental health care. Their goal: To create safe settings where people trapped in depression, trauma and addiction can gain legal access to the healing power of psychedelic drugs.

She was fascinated by the sense of cosmic connectedness — with people, nature or themselves — that stayed with many of the subjects long after their trips.

Watts will take center stage in this psychedelic renaissance in August, when she will be the clinical lead for a year-and-a-half-long study to test whether psilocybin — the active ingredient in magic mushrooms — could be more effective than a standard anti-depressant. It could be a landmark in her comrades’ broader struggle to transform mainstream psychiatry, which has developed an arsenal of pills to numb the symptoms of mental disorders, but needs new tools to tackle their causes.

“The thing about psychedelics is what they get you hooked on is your deep, true self,” Watts says, surrounded by research papers spread amid potted wisteria, honeysuckle and geraniums on the roof of her houseboat — her open-air office when the sun shines. “People are so caught in the prisons of their minds, and there’s just something so beautiful about this because it can really just take people into their heart.”

Watts’ curiosity about psychedelics was piqued five years ago when her friend, Carys Vaughan, returned from Peru unscathed. While there are plenty of reports of spiritual seekers suffering soul-searing damage at badly run ayahuasca retreats, Vaughan stepped off the plane clear-eyed and radiant. Freed from anxiety, she quit her sales job to work for a charity, fell in love and had two children — blessings she attributes to the visceral, priority-shifting experience of the plant medicine.

As Watts watched her friend’s life change, her relief was tempered by perplexity: Nothing in her training could explain such a dramatic shift, nor was she familiar with psychedelic research. She seemed an unlikely recruit for the revival. Growing up in the quiet town of Stamford, Lincolnshire, Watts had once imagined a future as a barrister. Her mother and older sister were psychologists, but the law seemed a way to be both sensible and different. Watts had planned to start legal training after graduating with a degree in English literature.

She realized she was on the wrong path while working in a prosecutor’s office that was charging a suspect who had turned to heroin to blot out childhood memories of being raped by her father and brothers. When Watts asked the prosecutor what sort of life the defendant could look forward to in jail, he snapped that if she wanted to ask such questions, she would be better off as a psychologist, not a lawyer.

Watts went on to assist with group therapy in a prison before studying psychology at University College London and joining a team working with families in gritty inner-city neighborhoods. It was only when her daughter was born that she found the time to start reckoning with Vaughan’s transformation, spending long nights of her maternity leave devouring literature on psychedelics.

Her big break came when she was taken on as a volunteer “guide” on a pilot study at Imperial College London on the impact of synthetic psilocybin on long-term depression, led by the neuroscientist Robin Carhart-Harris. Convinced that she would only be able to provide the best possible support if she underwent a high-dose psychedelic session herself, Watts booked a place on a legal psilocybin retreat in the Netherlands. The experience left her in no doubt as to the substance’s potential as a catalyst for profound inner work. As the study unfolded, Watts’ job was to sit with participants as they rode the psychic roller coaster unleashed by the drug and conduct follow-up interviews. She was fascinated by the sense of cosmic connectedness — with people, nature or themselves — that stayed with many of the subjects long after their trips.

Hearing about these experiences reminded Watts of poems she had studied by Gerard Manley Hopkins: “As Kingfishers Catch Fire,” on bliss, and “No Worst, There Is None,” on suicidal despair. Her epiphany only deepened her conviction that reconciling the worlds of art, science, clinical research and sacred ceremony was her new calling.

“She’s very much a connector; she brings people together,” says Michelle Baker Jones, a therapist who worked alongside Watts as a guide. “She brings a warmth into the team. She’s very open to people, and I think that’s really key in this type of work.”

The study showed that most of the 20 participants had obtained at least five weeks of relief from their symptoms, and some were still depression-free at six months. Despite the hurdles to working with psilocybin — which U.K. law classifies alongside heroin, crystal meth and cocaine — Watts is now working full-time to prepare for the more ambitious study pitting the drug against a commonly prescribed anti-depressant called escitalopram, which belongs to the same family as Prozac.

Even within the psychedelic science community there are skeptics. Katherine MacLean, a research scientist who worked on a psilocybin trial at Johns Hopkins, says the substance is only likely to help lift entrenched depression if people undertake the painstaking work of changing the way they live once the afterglow has faded. She also questions how safe it is to give the drug to very depressed patients. “I don’t think the clinical model anyone is working with right now is going to somehow miraculously cure depression,” MacLean says. “Unless you’re really willing to make those core changes, then psilocybin is not going to change your life for you.”

Watts is mindful of such concerns. In August, she and Baker Jones co-founded a monthly Psychedelic Integration Group to help people process ego-shattering trips and translate their insights into action. Her ultimate goal is to open a clinic to offer psychedelic-assisted therapy to anybody who needs it — assuming drug laws relax. “You could imagine a futuristic, incredible health center where we’re really exploring consciousness,” Watts says, no longer the rigid clinician she once was. “Because it’s still the great mystery.”