New analysis of the most recent clinical trials on psychedelics is adding weight to the argument that once-shunned drugs may be the mental health field’s new secret weapon.

The paper, published in the Canadian Medical Association Journal (CMAJ) on Tuesday, sifts through the small, randomized trials of both classical psychedelics (LSD, magic mushrooms) and enactogens (MDMA). Both types of hallucinogens have shown promise in treating mental health conditions, many of them with little to no side effects. The authors note potentially dangerous interactions with the drugs, but suggest that controlled, scientific studies be increased—both in number and scale.

Psychedelics, many of which were first used in cultural gatherings for worship and healing, have long fascinated the scientific world. One of the first to delve into the medical effects of hallucinogens was Albert Hoffman, who synthesized lysergic acid diethylamide (LSD) in 1938. After accidentally ingesting it in 1943, he became fascinated with its therapeutic benefits, deeming it the “medicine of the soul.”

By the 1950s, U.S. scientists had begun testing the drugs rigorously—in part fueled by the Central Intelligence Agency, which was looking for forms of mind control. As the drug got wrapped up in the counterculture of the 1960 and ’70s, it ushered in a period of fear and paranoia that led to its prohibition and classification as highly addictive and lacking medical value.

For more than three decades, the drugs remained largely untested by the medical world, but as scientists have slowly begun to perform small-scale studies, questions about its potential benefits are resurfacing—particularly in three areas: anxiety, addiction, and post-traumatic stress disorder.

Anxiety is the first relationship to psychedelics that the CMAJ authors explore, specifically the connection to LSD and psilocybin. In 2014, Swiss researchers studied the therapeutic benefits of LSD-assisted therapy in reducing anxiety in 12 patients who had been diagnoses with life-threatening illnesses. One year later, nearly all of the 12 patients showed sustained reductions in anxiety with no adverse reactions.

In another study, 12 participants diagnosed with late-stage cancer—and corresponding anxiety—were put in a randomized trial in which half received psilocybin-assisted therapy (the active ingredient in “magic mushrooms”) and half received a placebo. Those that were given psilocybin showed a “significant reduction” in anxiety as well as an improved mood. Nearly all reported zero negative side effects.

Addiction is perhaps the most studied condition in relation to psychedelics, dating back to studies on treating alcohol dependence with psilocybin in the 1960s. In 2008, two scientists from the Norwegian University of Science and Technology published a retrospective analysis of the long-buried research and found that alcoholics who were given psychedelics (vs. a placebo) had a significantly better chance of curbing alcohol use.

One of the few recent studies on psychedelics as a potential antidote to addiction involved 10 participants in New Mexico who reduced their percentage of heavy drinking days by more than half after undergoing psilocybin-assisted therapy. A preliminary evaluation has been done on the potential for the drug to help curb tobacco dependence, as well as cocaine and heroin. Canadian researchers are investigating the use of ayahuasca, a psychedelic brew made from plants in the Amazon, at addiction clinics in Latin America.

The final ailment analyzed by the authors is post-traumatic stress disorder, which researchers have found may be treatable with the help of MDMA. One pilot study on 19 participants with drug-resistant PTSD showed a “significant and sustained-reduction in PTSD,” in 83 percent of those given MDMA-assisted therapy—compared to just 25 percent in the placebo group. The therapy proved so effective that, after it, some no longer fit the diagnosis of PTSD.

While many of the participants in the studies reported zero side effects from the treatment, the authors are quick to point out that psychedelics do not come without risks. The National Institute on Drug Abuse highlights four specific hallucinogens all of which they say can be extremely dangerous and potentially addictive. The side effects for LSD are listed as ranging from increased heart rate to tremors; those for magic mushrooms, muscle weakness to vomiting—or risk of consuming poisonous mushrooms.

Others outside of NIDA are similarly wary of the media glamorizing a class of drugs that remains vastly understudied. The authors note that there have been reports of psychosis resulting from unmonitored use of psychedelics, as well as “flashbacks,” (technically called Hallucinogen Persisting Perception Disorder (HPPD)). In a February piece for Scientific American, John Hogan, author of the 2003 book Rational Mysticism, expressed concern about downplaying bad trips.

While he agrees that psychedelics may be beneficial, he cites specific examples of medical studies gone wrong—specifically one on DMT by Hoffman in 1999, which left at least 25 participants suffering from “terrifying hallucinations of ‘aliens’ that took the shape of robots, insects or reptiles.” During an interview in 1999, Hoffman told Hogan that LSD “can hurt you, it can disturb you, it can make you crazy.”

One of the most prominent researchers on the topic, Dr. Matthew Johnson, spoke with CMAJ about the analysis on a podcast this week. Associate Professor of Psychiatry and Behavioral Sciences at Johns Hopkins University School of Medicine, Johnson deems the effects of psychedelics on addiction “remarkable” and potentially game-changing. “Across the board we’re seeing impressive results that are certainly worthy of very careful and thorough follow-up,” he says.

In the conclusion, the authors suggest that those outside of the medical field—like elected officials and civil servants—become acquainted with research of psychedelics, as it may prove vital to improved health care. “Continued medical research and scientific inquiry into psychedelic drugs may offer new ways to treat mental illness and addiction in patients who do not benefit from currently available treatments,” they write. “The re-emerging paradigm of psychedelic medicine may open clinical and therapeutic doors long closed.”