Microdosed LSD did no better than placebo for adult ADHD in a six week randomised trial
53 adults with ADHD took 20 micrograms of LSD or a placebo twice a week for six weeks. Symptoms fell 7.1 points on LSD and 8.9 on placebo, with no difference between groups. LSD was well tolerated.
Reasonable evidence with real limitations. how we score evidence
Caveat on this rating: One small phase 2A trial at a single dose; a null result cannot rule out benefit at other doses or durations. Industry-sponsored (Mind Medicine), and the sponsor reported a null result.
The first randomised trial of microdosing for a psychiatric diagnosis, and its result was null.
Significant findings
Mueller and colleagues (JAMA Psychiatry, 2025) ran a six week, double-blind, placebo-controlled phase 2A trial at two centres, University Hospital Basel and Maastricht University, between December 2021 and December 2023. Adults aged 18 to 65 with a prior ADHD diagnosis and moderate to severe symptoms received either 20 micrograms of LSD or a placebo twice weekly, twelve doses in all. The primary outcome was the change in the observer-rated Adult Investigator Symptom Rating Scale (AISRS) from baseline to week 6.
53 people were randomised, 27 to LSD and 26 to placebo; mean age 37, 42 percent female. "The LSD group presented a mean AISRS improvement of -7.1 points (95% CI, -10.1 to -4.0). The placebo group presented a mean AISRS improvement of -8.9 points (95% CI, -12.0 to -5.8), with no difference between groups." The authors concluded that repeated low-dose LSD "was safe in an outpatient setting, but it was not more efficacious than placebo in reducing ADHD symptoms."
The other direction
This is one small phase 2A trial at one dose and one schedule, so it cannot rule out a benefit at other doses, in other people, or over longer periods. Both groups improved by a similar amount, which says the placebo response in ADHD trials is large. On the safety side the result is reassuring for a supervised six week course and says nothing about years of use. The study was financed by Mind Medicine, which was the legal sponsor, supervised the study and provided data; the paper says the company had no role in analysis or writing. A sponsor with a commercial interest in a positive result reported a null one.
What this does not show
It does not show that microdosing is harmless outside a trial, where doses are not measured and products are not tested. LSD is not approved for ADHD or any other use. It is not a reason to start, stop or change any ADHD treatment.
Worth asking
If someone tells me microdosing helps ADHD, which controlled trial are they pointing to?
Source
Safety and Efficacy of Repeated Low-Dose LSD for ADHD Treatment in Adults: A Randomized Clinical Trial — Mueller L, Santos de Jesus J, Schmid Y, Müller F, Becker A, Klaiber A, Straumann I, Luethi D, Haijen ECHM, Hurks PPM, Kuypers KPC, Liechti ME (2025)
Top-tier peer-reviewed journal
Read the source: https://doi.org/10.1001/jamapsychiatry.2025.0044
DOI: 10.1001/jamapsychiatry.2025.0044
How this was scored
- Study design
- Randomised controlled trial
- Funding
- Industry funded
- Published in
- Top-tier peer-reviewed journal
- Sample size
- 53
- Preregistered
- Yes
- Conflicts disclosed
- Yes
- Independent of proponent
- not recorded
- Retracted
- No
Read the full scoring rubric, including what it can't tell you.
Published October 21, 2026.
Questions
How strong is the evidence behind this?
veisund rates this source "moderate evidence". Reasonable evidence with real limitations. It scores 62 out of 100 on our published rubric. One caveat travels with that badge: One small phase 2A trial at a single dose; a null result cannot rule out benefit at other doses or durations. Industry-sponsored (Mind Medicine), and the sponsor reported a null result. The score is calculated from recorded facts about the source — study design, funding, publication venue, sample size, preregistration — not typed in by an editor.
What is the source for this?
Safety and Efficacy of Repeated Low-Dose LSD for ADHD Treatment in Adults: A Randomized Clinical Trial — Mueller L, Santos de Jesus J, Schmid Y, Müller F, Becker A, Klaiber A, Straumann I, Luethi D, Haijen ECHM, Hurks PPM, Kuypers KPC, Liechti ME (2025). Published in: Top-tier peer-reviewed journal. DOI: 10.1001/jamapsychiatry.2025.0044. The full source is linked on this page so you can read it yourself.
Who paid for this research, and does that matter?
Study design: Randomised controlled trial. Funding: Industry funded. Independence from the proponent is not recorded. Industry sponsorship is one of the most reliably measured biases in medicine, which is why funding carries real weight in the score rather than sitting in a footnote.
Is this medical advice?
This is information to bring to your prescriber, not medical advice and not a reason to change anything on your own. Nothing here is an instruction to stop or reduce a medication. If you are in crisis, call or text 988.
This is information to bring to your prescriber, not medical advice and not a reason to change anything on your own. Nothing here is an instruction to stop or reduce a medication. If you are in crisis, call or text 988.