Promising early results from largest-ever trial testing LSD for anxiety

Biopharmaceutical company MindMed has announced the first topline data from a novel Phase 2 trial testing high doses of LSD as a treatment for anxiety. The results indicate one to two LSD sessions can generate rapid and sustained reductions to anxiety, however, significantly larger trials will be needed to validate these findings.

A small but landmark study published in 2014 is the only modern research to date investigating the potential use of LSD as a treatment for anxiety. That pilot trial looked at the safety and efficacy of LSD-assisted psychotherapy in 12 patients experiencing anxiety associated with life-threatening diseases.

The results from that earlier study were promising, and a 12-month follow-up investigation suggested the benefits of treatment may be long-lasting. But until now there hasn’t been any further robust research looking at the impact of LSD on anxiety.

This new trial was conducted at University Hospital Basel in Switzerland. The trial was randomized, and placebo-controlled with a crossover design enrolling 46 participants.

The participants completed two high-dose (200-microgram) LSD sessions, six weeks apart. The primary endpoint was a reduction in anxiety 16 weeks after the second LSD session, as measured on a scale called STAI (State-Trait Anxiety Inventory), a common test used to quantify anxiety.

The data revealed by MindMed indicates 65 percent (13 out of 20) patients in the LSD group demonstrated a clinically significant reduction in STAI scores of more than 30 percent. Only nine percent of the placebo group (two out of 22) showed similar clinical improvements.

The results indicate the treatment was generally safe with only mild adverse effects reported by most subjects. The announcement did report one serious adverse treatment event during an LSD session described as “acute transient anxiety and delusions.” This subject required sedatives but no long-term adverse effects were noted.

It is important to stress these results have only been revealed so far by press release and in a presentation at the recent PSYCH Symposium in London. So they are limited in their detail and it is hoped a more complete picture of the trial will be published soon in a peer-reviewed journal.

An interesting feature of this trial is the absence of any comprehensive psychotherapy protocol accompanying the psychedelic sessions. Most modern psychedelic medicine is being investigated as an adjunct to rigorous psychotherapy sessions both before and after a drug treatment, to integrate the experience.

This particular trial seemed to focus solely on the pharmacological action of an LSD experience with no accompanying psychotherapy. In that regard it is certainly compelling to see clinical benefits from LSD without supporting psychotherapy.

“… we designed a robust, randomized, placebo-controlled clinical trial with a long follow-up period to extend the promising findings of previously conducted smaller, open-label trials,” said co-primary investigator on the trial Matthias Liechti, in a press release from MindMed. “We are extremely encouraged by the results presented today, demonstrating the long-lasting and strong reduction in patients suffering from anxiety. We look forward to reporting additional analyses and further investigating the therapeutic potential of LSD for patients suffering from anxiety disorders."

MindMed is now beginning a Phase 2b trial to expand on these findings and further explore LSD as a treatment for anxiety disorders.

Source: MindMed