In brief
- A team from Wroclaw Medical University (Poland) has published the most comprehensive systematic review to date on psychedelics and adult ADHD.
- Of all available literature, five studies met the review’s inclusion criteria, and the only randomized, double-blind trial using LSD microdoses showed no difference compared to a placebo.
- The authors call for larger, more rigorous trials and warn that psychedelics should not replace evidence-based treatments for ADHD.
A systematic review published in the International Journal of Molecular Sciences concludes that, based on data available today, it cannot be claimed that microdosing LSD or other psychedelics is effective for treating attention-deficit/hyperactivity disorder (ADHD) in adults. The study, authored by James Chmiel, Agnieszka Malinowska, and Professor Donata Kurpas, puts into perspective the growing interest in self-medicating with microdoses often discussed in online forums and social media.
Five included studies, with related cohorts and differing designs
The Polish team tracked available literature on classic psychedelics (LSD, psilocybin, ayahuasca) and ADHD symptoms in adults. Of all published work, five studies met its inclusion criteria: three observational studies on microdosing (involving individuals who were already self-medicating and responding to questionnaires), one randomized, double-blind clinical trial with low doses of LSD, and a pilot study on the ritual use of ayahuasca. This body of evidence, according to the authors themselves, is too small to draw firm conclusions in any direction.
The only controlled trial found no difference from placebo
The most relevant data comes from that randomized trial, previously published in JAMA Psychiatry: 53 adults with ADHD received either low doses of LSD or a placebo twice a week for six weeks (twelve administrations in total). Symptoms improved in both groups—7.1 points in the LSD group versus 8.9 in the placebo group—with no statistically significant difference between them and no serious adverse effects. While observational microdosing studies have reported subjective improvements in concentration and mood, these open-label, uncontrolled designs are highly vulnerable to the placebo effect and expectation bias.
Why there is a lack of biological fit
The review also examines biological plausibility: classic psychedelics act primarily on 5-HT2A serotonin receptors, whereas ADHD is explained mainly by alterations in dopaminergic and noradrenergic circuits, which are the targets of standard treatments. Kurpas notes that this mechanistic mismatch suggests caution before extrapolating the enthusiasm psychedelics have generated for depression or PTSD. Furthermore, there are limitations common to almost all studies: small sample sizes, heterogeneous substances and doses, short follow-ups, and a lack of safety data for people with comorbid psychiatric disorders, which are common in adult ADHD.
What this implies
The authors do not rule out the possibility that future, better-designed trials with larger samples might find specific benefits, and they explicitly call for such research to be funded. For now, however, the conclusion is one of caution: current evidence does not support using psychedelics, including microdoses, as an alternative to validated ADHD treatments, and experiences shared online should not replace medical judgment.
Source
- Wroclaw Medical University. “Psychedelics and ADHD” (review: Chmiel J, Malinowska A, Kurpas D. “The Use of Psychedelics in the Treatment of Adult ADHD: A Systematic and Mechanistic Review”, International Journal of Molecular Sciences, 2026, 27(8):3453). Wroclaw Medical University, June 26, 2026.
Educational content written from a harm reduction perspective and with respect for individual freedom. It is not a substitute for advice from a healthcare professional and is not intended to encourage or condemn any drug use.
