The psychedelic effects of magic mushrooms may help relieve depression, anxiety, and "existential distress" in ways unlike any traditional anti-depressants or anti-anxiety medications, according to new research.

The drug is being studied in limited trials in the US and abroad, where scientists are trying to understand through brain imaging tests on cancer patients and those with mental disorders like obsessive-compulsive disorder how the active chemical in mushrooms — psilocybin — actually affects the brain when it is taken.

Scientists at King's College, London, released research in late October in which they studied the brain images of 15 healthy volunteers who took psilocybin. They found that their brains showed significantly increased connectivity, in which regions of the brain that typically do not communicate with one another do communicate under the influence of mushrooms. The effect could help explain "synaesthesia" or the sensation of associating numbers with colors or sounds, they wrote.

"We find that the psychedelic state is associated with a less constrained and more intercommunicative mode of brain function, which is consistent with descriptions of the nature of consciousness in the psychedelic state," they wrote.

The authors of that study were not available for comment for VICE News today, but another researcher working in the United States said that brain imaging is one of a handful of studies to better understand psilocybin right now.

Stephen Ross, a professor of psychiatry at NYU, said that although psychedelic mushrooms are a class one illegal drug, over 400 doses have been administered in special medical research trials in the US at universities including NYU, Johns Hopkins, UCLA, and the University of New Mexico.

Ross has been leading one of those studies, examining the psychological effects of psilocybin on cancer patients. Though his research has not been fully analyzed or published yet, he said that preliminary findings show that the psilocybin doses his patients received helped boost their outlook toward cancer.

Thirty patients were part of Ross's randomized clinical study in New York, in which they came to him with serious anxiety and depression over their cancer diagnoses. Some were given psilocybin, while others were given a placebo; Ross said that those with psilocybin treatment saw effects from one dose lasting up to six weeks.

"They came to us with cancer, they were dying, they were terrified of dying of cancer, they had terrible anxiety and depression, and they were really made much better after getting the drug," Ross said. "The patients had big levels of reductions in distress… Their orientation toward cancer was profoundly altered."

Significantly, Ross reported that there have been no "bad trips" associated with psilocybin research. In his study, individuals were screened for major mental health issues and addiction, and then those deemed stable enough to receive the drug were given the doses in a safe setting.

The individual received the drug in pill form in a living-room like setting with two therapists in the room, who performed a ritual of holding hands while it was taken and discussing the patient's intention towards cancer. The patient was then given a shade mask and could lie down on the couch while under the therapist's supervision for about eight hours. For the first three or four hours they would seem to be sleeping, but would then wake up and discuss what they had experienced, he said.

"What they described was interesting encounters with transcendent forces and journeying to other parts of their lives," he said. "They would tell you stories of where they've been, and since the intention going into experiences was to deal with cancer, it's no wonder they would come back saying they've had these consequential encounters with cancer, seeing cancer inside of them like a black cloud, or having family members enter and hold them, and seeing the black cloud going away."

Ross explained that all psychedelic drugs, including psilocybin, LSD, and peyote, activate a serotonin receptor in the brain, though scientists don't understand quite what happens next to cause a psychedelic effect.

"We're getting more evidence from neuron-imaging about what's happening, about how they profoundly alter consciousness," he said. "It looks like it puts people in touch with the unconscious mind. Normally the brain constrains reality, it gives us a smaller picture of the world, and these drugs give you greater access to perceptive stimuli."

Ross's is one of a number of studies that could lead to psilocybin being used as a prescription treatment for mental disorders. UCLA and Johns Hopkins are also studying psilocybin's effects on cancer patients facing depression and anxiety. Other studies, including one from the University of Arizona and one from the University of New Mexico, have looked at the effects of psilocybin on obsessive-compulsive disorder (it was found to reduce symptoms) and alcoholism (ongoing).

The drug will have to undergo phase two and phase three trials before it goes to the FDA for approval as a medication, Ross said, but that could happen in 3-5 years.

"There's no medicine we have that deals with existential stress, with fear of death, he said. "Typical anti-anxiety drugs don't deal with that in any way. Psilocybin does, and we're still trying to figure out in what way it helps people deal with their death and mortality."

Francisco Moreno, MD, professor of psychiatry at the University of Arizona and a researcher on the Obsessive Compulsive Disorder-psilocybin study, told VICE News that psilocybin shows a rapid decrease in symptom severity for OCD in people who had failed to improve with standard care.

"I think psilocybin is safe in the context of medically supervised environment," Moreno said. "Our small pilot study suggested efficacy on a single dose cross sectional measure, though it has not been tested in a real life clinical setting."

Moreno said that he is not optimistic about legalization anytime soon.

"I don't anticipate approval soon, but I hope for more studies that support safety and efficacy," he added.

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