CATEGORY: BRAIN & MENTAL HEALTH
Can one carefully supervised dose of LSD quiet an anxious mind, and for how long? Researchers at 22 US clinics put that question to a proper test in 198 adults with moderate-to-severe generalized anxiety disorder, the condition in which worry becomes constant, exhausting and hard to switch off. Four weeks after a single dose of MM120, a pharmaceutical form of LSD, the two higher doses had lowered anxiety scores by 5 to 6 points more than placebo on a 56-point clinical scale, where a change of about 2.5 points is the smallest a person would notice.1 The two lower doses did no better than placebo.
No Therapy Sessions, Just the Drug
Every participant swallowed their dose at a clinic and stayed under supervision until its effects wore off. A randomization schedule, not any doctor’s judgment, sorted them into five groups: 25, 50, 100 or 200 micrograms of MM120, or a placebo. What sets this trial apart from most psychedelic research is what it left out. There was no accompanying psychotherapy. The researchers wanted to know whether the drug itself moves anxiety, and their stated hypothesis was that relief would grow with the dose. It did, up to a point. The 100-microgram dose worked about as well as 200 while causing less nausea, which is why the company chose it for the larger trials now running.
The Benefit Outlasted the Trip, but Blinding Didn’t Survive It
The drug’s visible effects lasted a day. The measured benefit lasted longer: at eight weeks, people on the two higher doses still scored meaningfully lower on the anxiety interview than the placebo group. Two cautions belong beside that result. First, everyone improved, including people on placebo, whose scores fell 14 points from the study’s start. The drug’s added benefit sits on top of that, and it’s more modest than headlines about psychedelics tend to suggest. Second, nearly everyone on the higher doses experienced visual distortions, so most participants could guess what they’d taken. That guessing can inflate a result, and no anxiety trial of a psychedelic has fully solved it.
Side effects clustered on dosing day. Visual changes affected 92% of the 100-microgram group, nausea 40%, headache about a third. One serious adverse event occurred across the four drug groups, and few people quit the study over side effects. MM120 isn’t an approved medicine. This was a mid-stage trial, run and funded by the drug’s maker, and phase 3 results will decide whether regulators ever review it. For people whose anxiety hasn’t yielded to antidepressants or talk therapy, that’s the trial worth watching.
Key Takeaways
- A single supervised dose of MM120, a pharmaceutical form of LSD, lowered generalized-anxiety scores 5 to 6 points more than placebo at four weeks, a difference roughly twice the smallest change a person would notice.
- Relief rose with dose up to 100 micrograms; the lower doses added nothing over placebo, and 200 micrograms added mostly side effects.
- Placebo recipients improved substantially too, and near-universal visual effects meant most participants could guess their assignment, which can flatter the results.
- The drug remains experimental: this was a 198-adult mid-stage trial funded by its maker, with larger trials still under way.
References
- Robison R, et al. Single Treatment With MM120 (Lysergide) in Generalized Anxiety Disorder: A Randomized Clinical Trial. JAMA. 2025;334(15):1358–1372. link