The effects of psychedelics on attention deficit and hyperactivity disorder - a systematic review

OBJECTIVES: Attention deficit and hyperactivity disorder (ADHD) is a prevalent neuropsychiatric disorder (Drechsler et al., 2020). Recently, psychedelics have become of interest regarding developing treatment options for ADHD. The aim of this systematic review is to find all studies from the APA PsychInfo and MEDLINE databases, where psychedelics have been used for ADHD and assess whether further clinical studies are warranted. METHODS: APA PsychInfo and MEDLINE were searched on the 20th of August 2025 for studies discussing ADHD and lysergic acid diethylamide (LSD) or psilocybin or dimethyltryptamine (DMT) or mescaline or phencyclidine or 3,4-methylenedioxymethamphetamine (MDMA) or ketamine. Primary research articles in English where the effects of the psychedelics mentioned on ADHD in humans were included. RESULTS: = 1023 results were identified. Six studies were included - one randomised controlled trial (RCT) finding no statistically important difference compared to placebo, 3 cross sectional studies where respondents reported positive effect of psychedelics and one where the statistically important improvement was measured by the Child Bipolar Questionnaire. In addition, one case study, where both, depressive symptoms and functioning improved with ketamine. CONCLUSIONS: There is not sufficient evidence to give recommendations on psychedelic use for ADHD. In addition, it is not known whether patients, whose depressive symptoms have responded positively to ketamine, have also had ADHD. Also, no research was found on how psychedelics affect patient subgroups with different etiopathology causing their symptoms. Although only six studies filled the inclusion criteria, they bring out valuable implications for further research.