The psychedelic drug LSD is poised to become the next big thing in treating generalized anxiety disorder.

On Wednesday morning, Definium Therapeutics announced the primary findings from a Phase III trial testing its proprietary version of LSD, named DT120. Compared to people taking a placebo, those on DT120 saw a noticeable decline in their anxiety symptoms, the trial showed. It’s the second large-scale trial success for Definium and DT120 in recent months, both of which should pave the way for LSD to become an approved psychiatric treatment in the near future.

LSD as medicine

LSD (short for lysergic acid diethylamide) is a semisynthetic drug derived from the ergot fungus and is well known for its psychedelic and hallucinogenic effects. Itâs usually taken as an oral dissolving tablet, with its effects typically lasting between 6 and 12 hours, depending on the dosage. In recent years, LSD has received (renewed) attention from scientists as a potential medication for various mental health conditions.

Definium, previously known as MindMed, has been developing DT120 as a treatment for major depressive disorder and generalized anxiety disorder (GAD). In late June, the company released the results of its randomized double-blinded, placebo-controlled Emerge trial, which showed that people taking a single dose of DT120 experienced a significantly greater reduction in their depression symptoms than those taking a placebo.

This latest similarly designed trial, codenamed Voyage, tested LSD for anxiety. It involved 214 participants, ages 18 to 74 years, with diagnosed GAD. People were randomized to receive either a placebo or a single 100-microgram dose of DT120; then they were monitored for 12 weeks.

By the 12-week mark, the trial met its primary goal: people on DT120 experienced a noticeable and clinically significant reduction in anxiety relative to the placebo group, based on a commonly used scale. More people in the treatment group also saw a 50% or more reduction in their symptom severity, a sign of treatment response (43% versus 16% in the placebo group); more met the criteria for mild anxiety (51% versus 23%); and more saw their symptoms decline so much that they were considered in remission (14% versus 4%).

A likely approval?

The company’s findings should ideally be vetted through peer review. And generally, the Food and Drug Administration expects to see two positive trials before it will approve a drug for a given condition. So it’s not a guarantee right now that DT120 will clear the review process without issues. To that end, Definium is currently carrying out further Phase III studies for both depression and anxiety.

Still, the company’s findings are undoubtedly the most promising data seen yet for LSD’s possible future as psychedelic medicine. DT120 has already received a breakthrough therapy designation from the FDA for GAD, a label intended to speed up the approval review process. And we may have not even hit the therapeutic ceiling of the drug. Definium and other research teams are also investigating LSD as a treatment for posttraumatic stress disorder, with the company’s Phase III trial expected to start next year.