Dinah Bazer, seen at her home in Brooklyn, said participating in the NYU psilocybin trial was a “life-changing” experience. (Sasha Arutyunova/For The Washington Post)

A single dose of psilocybin, the long-banned active compound in “magic mushrooms,” significantly reduced anxiety, depression and the fear of death among cancer patients for months at a time, according to two studies published Thursday.

Eighty people in separate clinical trials at Johns Hopkins University School of Medicine and New York University Langone Medical Center were given psilocybin under close supervision. The vast majority experienced an increase in optimism, a feeling of connection with other people, and mystical and spiritual experiences. The effects persisted through the six-month follow-up period.

The research, published in the Journal of Psychopharmacology, is the latest to suggest that psilocybin and other hallucinogenic drugs might be beneficial for people with depression, post-traumatic stress disorder, and drug, alcohol or tobacco addictions.

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Craig Blinderman, a palliative care expert at New York-Presbyterian/Columbia University Medical Center who was not involved in the research, called the results “groundbreaking.” If they are confirmed, he said, psilocybin could become a powerful tool in easing “existential distress” in people with life-threatening cancer and other diseases.

Researchers at NYU's Langone Medical Center explain their research giving cancer patients suffering from anxiety or depression a dose of psilocybin, the drug found in "magic mushrooms." (New York University Langone Medical Center)

Other scientists cautioned that psilocybin and other hallucinogens can be unpredictable.

For Dinah Bazer, a 69-year-old Brooklyn resident, the NYU trial was a “life-changing” experience. Diagnosed with ovarian cancer in May 2010, she was treated successfully but “really went nuts” worrying that the cancer would return, she said.

In the fall of 2012, she was given psilocybin — though at the time she was not told whether she was getting the drug or a placebo — and stretched out on a couch listening to music under the watchful eye of two therapists. Soon, she said, she saw a black mass, like a giant lump of coal under her rib — her fear. Erupting in anger, she shouted, “Get the f---out! I won’t be eaten alive!”

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Later during the experience, Bazer, an atheist, said she felt “bathed in God’s love.” She said she has not worried about a return of the cancer since.

The Hopkins and NYU studies had some differences but produced almost identical results. Roland Griffiths, a psychopharmacologist who led the Hopkins study, said the key finding — that a single dose of psilocybin produced “enduring” relief — represented a possible new model for treating other psychiatric ailments. Psychiatrist Stephen Ross, who led the NYU study, said it is critical to find new treatments for anguished cancer patients because such distress is linked to increased rates of suicide and decreased survival.

In both studies, about 80 percent of participants said the psilocybin’s effects lasted for at least several months; more than 70 percent said the experiences were among the most meaningful of their lives. They reported no serious side effects.

In almost a dozen opinion pieces accompanying the studies, other researchers called for stepped-up research on hallucinogens. “It’s time to take psychedelic treatments in psychiatric and oncology seriously as we did in the 1950s and 1960s, which means we need to go back to the future,” wrote David Nutt, a psychiatrist at Imperial College London.

Joshua Gordon, director of the National Institute of Mental Health, called the research “fascinating.” He added that “anything that has that dramatic effect is worth looking at carefully.” But he also said that it was important to proceed cautiously because “sometimes people will try things on their own to see if it works, and that’s something you want to avoid.”

Others expressed additional concerns. Glen Hanson, a pharmacologist who is the director of the Utah Addiction Center at the University of Utah, warned that the drug is unpredictable and could cause extreme anxiety, even psychosis. Psychobiologist Bertha Madras of Harvard Medical School worried about “medicalizing” the drug.

“We are already seeing a national epidemic of opioid overdose deaths,” she said. “And if we medicalize another group of drugs, one has to weigh the cost-benefit equation to society. Will people think this is a safe drug . . . but will it, in fact, be a plague on society?”

Griffiths and Ross, the study leaders, said psilocybin is not addictive but agreed that it should not be used outside clinical trials, where participants are carefully screened.

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Both trials — NYU had 29 participants, and Hopkins had 51 — used synthetic psilocybin. The studies were randomized, and neither the patients nor their monitors knew who was receiving the drug and who was getting the placebo. Several weeks after the first dosing, participants received whatever treatment they had not received the first time.

Griffiths said he tried to minimize the placebo effect — in which patients perceive an improvement from an inactive treatment — by using a low dose of psilocybin as the placebo and a high dose as the treatment medication. The patients knew they would get psilocybin both times, but didn’t know the doses. He said there was such a large difference in the results that he didn’t think the placebo effect was a problem. NYU used niacin, a B vitamin known to produce a “rush,” as the placebo.

Psilocybin attracted intense interest from researchers in the 1950s and 1960s, but the work was shut down when the drug was banned under the 1970 Controlled Substances Act. Today, it is classified as a Schedule I drug, meaning it is deemed to have a high potential for abuse and no legitimate medical purpose.

In the past decade or so, research has slowly resumed, funded mostly by nonprofits and advocates who believe in psilocybin’s therapeutic value. The Hopkins and NYU studies, for example, were largely paid for by the Heffter Research Institute, a New Mexico nonprofit. George Greer, Heffter’s medical director, said the group was working with a nonprofit institute in Wisconsin to try to move the drug into larger, Phase 3 trials that would be required to receive Food and Drug Administration approval.

Petra, a 63-year-old Seattle resident who spoke on the condition that her last name not be used for privacy, was treated for ovarian cancer and, like Bazer, was worried it would recur. But during her treatment with psilocybin, she said, she calmed down.

“I felt an acceptance of the world as it is and myself as I am,” she said. She learned new ways to handle stress, such as meditation. Two years later, when doctors saw a suspicious lesion and suggested surgery, she urged them to wait, saying it was unlikely to be cancer — which turned out to be correct. “The psilocybin had knocked back my anxiety almost completely,” she said.