A new scientific review published in this month’s Journal of Psychiatric Practice reported that psychedelics have successfully been used to reduce symptoms linked to at least eight different psychiatric disorders. And since today is National Psilocybin Mushroom Day, we figured there was no better time to break down this news for you.

Researchers from the University of Texas Health Science Center at San Antonio reviewed sixteen previously-published studies exploring whether psychedelic drugs could help treat a variety of disorders. These original studies, published between 1946 and 2017, examined the effects of ibogaine, ketamine, LSD, MDMA, psilocybin, ayahuasca, and other drugs on patients suffering from conditions like depression, substance use disorders, and PTSD.

“The conditions treated ranged from depression to autism, with the largest volume of research dedicated to substance use disorders,” the researchers wrote. “The majority of studies that were reviewed demonstrated significant associations with improvement in the conditions investigated.” 

Out of the 16 studies reviewed, 15 found that hallucinogen-based therapy “produced clinically significant reduction in” symptoms of psychiatric disorders.

Specifically, the review noted two studies that found that ayahuasca helped reduce the symptoms of treatment resistant depression, and another study which found that MDMA-assisted therapy helped patients deal with PTSD associated with sexual trauma. Several other studies found that ibogaine, ketamine, LSD, and dipropyltryptamine (a synthetic hallucinogen known as DPT or “The Light”) all showed evidence of helping patients struggling with substance use disorder remain sober.

The researchers explained that many of these studies were flawed, due to small subject size or lack of control groups, making it “difficult to draw definite conclusions” about the research. However, the study concluded that “this body of pilot literature suggests the possibility of therapeutic benefit that could outweigh adverse events and warrants more rigorous, definitive investigation.”

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“Despite promising findings in therapeutic hallucinogen trials, current factors, including funding, laws, and stigma, continue to impose limitations on further research,” the review concluded. “Schedule I classification makes study development difficult, costly, and prolonged. Funding by both government and pharmaceutical companies is nonexistent.”

Despite the ongoing federal prohibition of these drugs, research into their therapeutic potential has been booming in recent years. Both MDMA and psilocybin have been granted “breakthrough therapy” status by the Food and Drug Administration (FDA), allowing researchers to conduct federally-approved research on these drugs. Based on the success of these trials, both of these psychedelics could gain federal approval to be used under medical supervision within years. Ketamine, once known as party drug “Special K,” has already been approved by the FDA to help treat serious depression.

The University of Texas review notes that around 40 million Americans, or 15.3 percent of the country’s population, have used psychedelics, according to the 2015 National Survey on Drug Use and Health. That number may well be growing, as Denver and Oakland have both decriminalized psilocybin and other psychedelics, and other cities and states are working to do the same.