Review finds only six human studies on psychedelics and ADHD, and weak evidence overall

The question

Is there any human evidence that psychedelics or ketamine help with attention deficit and hyperactivity disorder (ADHD), and is further clinical research justified?

What they did

The authors searched two research databases, APA PsychInfo and MEDLINE, on 20 August 2025 for human studies linking ADHD with LSD, psilocybin, DMT, mescaline, phencyclidine, MDMA or ketamine. They included only primary research articles in English that reported effects of these drugs on ADHD. The search returned 1,023 records.

What they found

Six studies met the inclusion criteria. One was a randomized controlled trial, which found no statistically important difference compared with placebo. Three were cross-sectional studies in which respondents reported positive effects of psychedelics, and one measured a statistically important improvement using the Child Bipolar Questionnaire. There was also a single case report in which both depressive symptoms and day-to-day functioning improved with ketamine.

The fine print

Only six studies were found, and most were cross-sectional surveys or a single case report, which cannot show cause and effect. The one randomized trial found no benefit over placebo. The abstract does not report how many people were included in total, what doses were used, or how long participants were followed. The authors also note it is unclear whether the ketamine case involved ADHD at all, and no research examined different underlying causes of ADHD symptoms. This summary is based on the abstract only.

What it means

At present there is not enough evidence to say whether psychedelics or ketamine help ADHD, and the single randomized trial identified showed no benefit over placebo. The authors argue the existing studies point to questions worth testing in future clinical research.

Evidence grade: Low. A systematic review that found only six eligible human studies, mostly cross-sectional surveys and a case report, with just one randomized trial.

This summary is based on the study’s published abstract.