London-based psychiatrist Ben Sessa sometimes feels like a doctor at a nursing home.

"Psychiatry is a desperate place to live sometimes; it feels like a palliative care industry," Sessa said at a conference in London this July on the science of psychedelics. "We've almost given up hope that we can actually cure [many of our patients] and turn it around."

That's why he and several other scientists have turned a hopeful eye in recent years toward psychedelics, drugs that have been around for decades but have never been explored — at least legally — for medical use.

One of those drugs is MDMA, or ecstasy. The group leading the charge to get MDMA approved for medical use passed a major hurdle after the US Food and Drug Administration granted it a special designation that could fast-track its approval to treat PTSD.

Breakthrough therapy

The group behind the new research is the Multidisciplinary Association for Psychedelic Studies (MAPS), a nonprofit organization that is leading much of the research into psychedelics and mental illness in the US. MAPS' founder, Rick Doblin, said at the London conference that he believed MDMA was the "most likely" psychedelic to be adopted by psychiatric and psychotherapy professionals.

"MDMA is the most gentle of all the psychedelics," Doblin said.

Part of the premise of granting a treatment "breakthrough therapy" designation involves recognizing that it could have a meaningful advantage over existing treatments. As of August 27, MDMA has been granted this designation, meaning that it moves toward the final phase of medical trials that could one day lead to possible prescription use of the drug to treat PTSD.

A resurgence in interest surrounding psychedelics

The past year has seen a blossoming interest in exploring the use of psychedelics like ayahuasca and magic mushrooms for their potential to treat mental illnesses including depression and anxiety. Early studies suggest that the drugs reduce symptoms of both disorders by increasing the brain's connectivity in novel ways.

Psychedelic-based treatments "offer an opportunity to dig down and get to the heart of the problems that drive long term mental illness in a much more effective way than our current model, which is take daily medications to mask the symptoms and stay just-about level without digging down," Sessa said.

It's a source of hope to many people struck by conditions like anxiety and depression — especially those who haven't responded to traditional treatments like talk therapy and antidepressants.

Clark Martin, a cancer patient who participated in a medical trial of psilocybin (the active ingredient in magic mushrooms) for depression, said his experience was overwhelmingly positive. "With the psilocybin, you get an appreciation — it's out of time — of well-being, of simply being alive and a witness to life and to everything and to the mystery itself," Martin told Business Insider in January.

MDMA is different from magic mushrooms in many ways.

Known as ecstasy or "Molly," MDMA was created by pharmaceutical company Merck in 1912 and is currently considered an illegal substance with no medical benefit and a high potential for abuse. The drug is both a stimulant and a psychedelic, meaning it has both energy-raising and hallucinogenic properties, and it's been known to be dangerous when used without medical supervision because it raises body temperature and blood pressure. In the brain, MDMA amps up the activity of chemical messengers involved in mood regulation.

Yet researchers who study it say that these same characteristics could make it an ideal treatment for some types of mental illness. One arm of Doblin's research involves studying MDMA in veterans with PTSD in a setting which combines the drug with traditional talk therapy. In three of the sessions, patients are given the drug or a placebo and talk therapy; in another 12 sessions, they are given talk therapy alone.

Together, the two treatments could help produce faster and more measurable results, according to people involved in the research.

"Psychotherapy is painful, it's slow, it's fits and starts, you start to get to something important and then the patient disappears for a month at a time; they're very defended about getting down to it," said New York-based psychiatrist Julie Holland at the London conference. Holland is also the medical monitor for the MAPS study of MDMA for PTSD in veterans.

"MDMA-assisted psychotherapy allows the patient to be more sort of open to the process. It is a less painful process; MDMA can act as a catalyst to make the therapy go faster, be more efficient, be deeper, get to that malignant thing that needs to be taken out and examined in a more sort of peaceful environment with more acceptance," Holland said.

Researchers are hopeful that the new FDA designation will help them in their quest to provide relief to people who haven't benefited from traditional approaches.

"We need some new tools," said Sessa. "What psychedelic psychotherapy offers is really something quite unique."