Cognitive functioning associated with acute and subacute effects of classic psychedelics and MDMA - a systematic review and meta-analysis

Abstract

Classic psychedelics and MDMA have a colorful history of recreational use, and both have recently been re-evaluated as tools for the treatment of psychiatric disorders. Several studies have been carried out to assess potential long-term effects of a regular use on cognition, delivering distinct results for psychedelics and MDMA. However, to date knowledge is scarce on cognitive performance during acute effects of those substances. In this systematic review and meta-analysis, we investigate how cognitive functioning is affected by psychedelics and MDMA during the acute drug effects and the sub-acute (“afterglow”) window. Our quantitative analyses suggest that acute cognitive performance is differentially affected by psychedelics when compared to MDMA: psychedelics impair attention and executive function, whereas MDMA primarily affects memory, leaving executive functions and attention unaffected. Our qualitative analyses reveal that executive functioning and creativity may be increased during a window of at least 24 h after the acute effects of psychedelics have subsided, whereas no such results have been observed for MDMA. Our findings may contribute to inform recommendations on harm reduction for recreational settings and to help fostering differential approaches for the use of psychedelics and MDMA within a therapeutic framework.

Effects of Psychedelic Drug Use on Neurocognitive Function and Psychological and Social Quality of Life Domains: An International Online Study

“…However, analyses focusing on individual substances—LSD, psilocybin, alcohol, and THC—consistently found that higher doses were associated with impairments across all three cognitive domains. This is in line with previous research suggesting that high doses impair cognitive functioning, while lower doses may facilitate enhancement (Basedow et al, 2024; Bonnieux et al, 2023). Nevertheless, longitudinal and more consistent study designs are needed before conclusions can be drawn beyond acute effects only (Bălăeţ, 2022).…”

“…With regard to selective attention, our findings of (sub)acute impairment in recent users and increased accuracy in lifetime users are in line with previous research, though data on attentional bias are scarce (Basedow et al, 2024). Most notably, 39.66% (n=301) of the participants, all of whom belonged to the lifetime or recent user groups, stated that they were under the influence of a psychedelic drug while taking part in the study, preventing us from differentiating between acute and subacute effects.…”

Effects of Psychedelic Drug Use on Neurocognitive Function and Psychological and Social Quality of Life Domains: An International Online Study

“…However, analyses focusing on individual substances—LSD, psilocybin, alcohol, and THC—consistently found that higher doses were associated with impairments across all three cognitive domains. This is in line with previous research suggesting that high doses impair cognitive functioning, while lower doses may facilitate enhancement (Basedow et al, 2024; Bonnieux et al, 2023). Nevertheless, longitudinal and more consistent study designs are needed before conclusions can be drawn beyond acute effects only (Bălăeţ, 2022).…”

“…With regard to selective attention, our findings of (sub)acute impairment in recent users and increased accuracy in lifetime users are in line with previous research, though data on attentional bias are scarce (Basedow et al, 2024). Most notably, 39.66% (n=301) of the participants, all of whom belonged to the lifetime or recent user groups, stated that they were under the influence of a psychedelic drug while taking part in the study, preventing us from differentiating between acute and subacute effects.…”

Creativity under LSD: A reanalysis of Oscar Janiger’s LSD studies among professional artists.

“…Specifically, reducing transitions from incubation to illumination and decreasing engagement with validation stages during real-time artistic creation. These acute impairments during the psychedelic state align with broader patterns observed in literature, where macrodoses reliably impair creativity acutely but show tentative postacute improvements (Basedow et al, 2024; Bonnieux et al, 2023), although sustained enhancements beyond 1 week remain poorly supported (Evens et al, 2023; Murphy et al, 2025). Although the present study focused on creative products and could not possibly explore the underlying processes, this hypothesis merits further exploration.…”

Effects of LSD, DMT and psilocybin on cognitive and psychological functions: A systematic review of the literature

“…The aim of this review is to systematically explore these processes and their measurement in the context of psychedelic research. This review extends previous work (Basedow et al, 2024;Cardoso and de Barros Viana, 2023;Meshkat et al, 2024;Pouyan et al, 2022Pouyan et al, , 2023;;Ramos et al, 2024;Velit-Salazar et al, 2024) by specifically examining the effects of classic psychedelics on cognitive and psychological functions using experimental methods in placebo-controlled studies.…”

Effects of Psychedelic Drug Use on Neurocognitive Function and Psychological and Social Quality of Life Domains: An International Online Study

“…However, analyses focusing on individual substances—LSD, psilocybin, alcohol, and THC—consistently found that higher doses were associated with impairments across all three cognitive domains. This is in line with previous research suggesting that high doses impair cognitive functioning, while lower doses may facilitate enhancement (Basedow et al, 2024; Bonnieux et al, 2023). Nevertheless, longitudinal and more consistent study designs are needed before conclusions can be drawn beyond acute effects only (Bălăeţ, 2022).…”

“…With regard to selective attention, our findings of (sub)acute impairment in recent users and increased accuracy in lifetime users are in line with previous research, though data on attentional bias are scarce (Basedow et al, 2024). Most notably, 39.66% (n=301) of the participants, all of whom belonged to the lifetime or recent user groups, stated that they were under the influence of a psychedelic drug while taking part in the study, preventing us from differentiating between acute and subacute effects.…”

Creativity under LSD: A reanalysis of Oscar Janiger’s LSD studies among professional artists.

“…Specifically, reducing transitions from incubation to illumination and decreasing engagement with validation stages during real-time artistic creation. These acute impairments during the psychedelic state align with broader patterns observed in literature, where macrodoses reliably impair creativity acutely but show tentative postacute improvements (Basedow et al, 2024; Bonnieux et al, 2023), although sustained enhancements beyond 1 week remain poorly supported (Evens et al, 2023; Murphy et al, 2025). Although the present study focused on creative products and could not possibly explore the underlying processes, this hypothesis merits further exploration.…”

Effects of LSD, DMT and psilocybin on cognitive and psychological functions: A systematic review of the literature

“…The aim of this review is to systematically explore these processes and their measurement in the context of psychedelic research. This review extends previous work (Basedow et al, 2024;Cardoso and de Barros Viana, 2023;Meshkat et al, 2024;Pouyan et al, 2022Pouyan et al, , 2023;;Ramos et al, 2024;Velit-Salazar et al, 2024) by specifically examining the effects of classic psychedelics on cognitive and psychological functions using experimental methods in placebo-controlled studies.…”

Effects of Psychedelic Drug Use on Neurocognitive Function and Psychological and Social Quality of Life Domains: An International Online Study

“…However, analyses focusing on individual substances—LSD, psilocybin, alcohol, and THC—consistently found that higher doses were associated with impairments across all three cognitive domains. This is in line with previous research suggesting that high doses impair cognitive functioning, while lower doses may facilitate enhancement (Basedow et al, 2024; Bonnieux et al, 2023). Nevertheless, longitudinal and more consistent study designs are needed before conclusions can be drawn beyond acute effects only (Bălăeţ, 2022).…”

“…With regard to selective attention, our findings of (sub)acute impairment in recent users and increased accuracy in lifetime users are in line with previous research, though data on attentional bias are scarce (Basedow et al, 2024). Most notably, 39.66% (n=301) of the participants, all of whom belonged to the lifetime or recent user groups, stated that they were under the influence of a psychedelic drug while taking part in the study, preventing us from differentiating between acute and subacute effects.…”

Creativity under LSD: A reanalysis of Oscar Janiger’s LSD studies among professional artists.

“…Specifically, reducing transitions from incubation to illumination and decreasing engagement with validation stages during real-time artistic creation. These acute impairments during the psychedelic state align with broader patterns observed in literature, where macrodoses reliably impair creativity acutely but show tentative postacute improvements (Basedow et al, 2024; Bonnieux et al, 2023), although sustained enhancements beyond 1 week remain poorly supported (Evens et al, 2023; Murphy et al, 2025). Although the present study focused on creative products and could not possibly explore the underlying processes, this hypothesis merits further exploration.…”

Effects of LSD, DMT and psilocybin on cognitive and psychological functions: A systematic review of the literature

“…The aim of this review is to systematically explore these processes and their measurement in the context of psychedelic research. This review extends previous work (Basedow et al, 2024;Cardoso and de Barros Viana, 2023;Meshkat et al, 2024;Pouyan et al, 2022Pouyan et al, , 2023;;Ramos et al, 2024;Velit-Salazar et al, 2024) by specifically examining the effects of classic psychedelics on cognitive and psychological functions using experimental methods in placebo-controlled studies.…”