Effects of LSD, DMT and psilocybin on cognitive and psychological functions: A systematic review of the literature
Marten Kase, Karl Kristjan Kaup, Jaan Aru
Journal of Psychopharmacology February 16, 2026 DOI: 10.1177/02698811251412012 via OpenAlex
Summary
AI-generated from the abstractA systematic review of 32 placebo-controlled studies from 1990 to 2025 examined the acute and post-acute effects of LSD, DMT, and psilocybin on cognitive and psychological functions. Psychedelics tended to enhance emotional empathy but had no effect on cognitive empathy. Effects on memory varied by task and timing, with some impairments, enhancements, or no change. Dose-dependent impairments occurred in reaction time, attention, and inhibition tasks, though some studies found no effects. Recognition of negative stimuli was impaired under acute effects. Findings on cognitive flexibility were mixed. Many studies had small samples, and finding a reliable placebo is challenging due to psychedelics' unique subjective effects.
Study at a glance
| Characteristics | Systematic review Placebo-controlled Longitudinal Peer reviewed |
|---|---|
| Sample size | 32 |
| Population | Healthy volunteers and patient populations |
| Topics | Psilocybin |
| Keywords | Cognition Hallucinogen Empathy Dissociative |
| Citations | 1 |
| Key finding | Psychedelics tended to enhance emotional empathy but had no effect on cognitive empathy, and effects on memory, reaction time, attention, inhibition, and cognitive flexibility varied widely across tasks and studies. |
Abstract
We carried out a systematic review of modern-era (1990-2025) placebo-controlled studies assessing the acute and post-acute effects of lysergic acid diethylamide, dimethyltryptamine and psilocybin on cognitive and psychological functions. From February 28 to March 19, 2025, PubMed and APA PsychINFO were systematically searched for placebo-controlled studies examining the influence of psychedelics on empathy, reaction time, attention, inhibition, emotional processing, memory, cognitive flexibility, and related cognitive functions using experimental methods. Additional searches were done in Google Scholar. The systematic review included 32 studies. Psychedelics tended to enhance emotional empathy but had no effect on cognitive empathy. Psychedelics impaired, enhanced or had no effect on memory depending on the task and timing of the assessment. Dose-dependent impairments were seen in many of the reaction time, attention, and inhibition tasks, although some studies found no effects. Some studies found impaired recognition of negative stimuli under the acute effects of psychedelics. The findings regarding cognitive flexibility were mixed. Many studies had small samples, and it is hard to find a reliable placebo due to psychedelics' unique subjective effects. Future studies should use bigger samples and also study more longitudinal effects of psychedelics on cognitive and psychological functions.