A groundbreaking study published in Scientific reports offers the most comprehensive analysis to date of how classic psychedelics such as LSD and psilocybin, as well as the drug MDMA (commonly known as ecstasy), affect cognitive function during and after use. As PsyPost reported, research shows that these substances affect the brain in different ways, with psychedelics impairing attention and executive functions, while MDMA primarily disrupts memory.

Interestingly, the study also suggests that psychedelics may increase creativity and executive function after their immediate effects wear off—an effect not seen with MDMA. This finding is particularly relevant as use of these substances is increasing in both recreational and therapeutic settings, raising concerns about their cognitive risks and benefits.

Key findings of the study

The researchers conducted a meta-analysis combining data from 122 studies to examine the cognitive effects of psychedelics and MDMA, focusing on three cognitive areas: memory, executive function and attention.

• Psychedelics: During the acute phase, psychedelics impaired attention and executive functions, making it difficult for users to concentrate or make complex decisions. However, memory was less affected and some studies even reported no effect on memory performance. Notably, after the acute effects of psychedelics wore off, some cognitive functions, particularly executive functions and creativity, appeared to improve – an afterglow effect that could last up to 24 hours.
• MDMA: In contrast, MDMA primarily impaired memory in the acute phase and had little to no effect on attention and executive functions. The study found no evidence of an afterglow effect with MDMA, suggesting that cognitive functions returned to baseline after the effects of the drug wore off, without any lasting cognitive benefits.

Impact on recreational and therapeutic use

The different cognitive profiles of psychedelics and MDMA have important implications for both recreational use and therapeutic purposes. Recreational users can use understanding of these cognitive effects to promote safer consumption practices, such as avoiding activities that require concentration or decision-making while under the influence of psychedelics.

In therapeutic settings, the potential afterglow effect of psychedelics could be used to increase the effectiveness of therapy sessions following the psychedelic experience. At the same time, MDMA’s effects on memory could be useful in therapies for conditions such as PTSD, where interrupting traumatic memories is an important goal.

Research challenges and variability of effects

The study’s results also highlight the complexity of the effects of these substances on cognitive abilities. The researchers found considerable variability among the studies included in the meta-analysis, highlighting the challenges in drawing definitive conclusions.

“The most surprising result was the heterogeneity of the results,” said study author Lukas A. Basedow“Some people may retain cognitive abilities while under the influence of psychedelics, suggesting that the effects of these substances are not clear-cut or predictable.”

Future directions for psychedelics and MDMA research

Future research needs to address this variability by conducting more standardized neuropsychological tests and directly comparing the effects of different psychedelics and MDMA under the same conditions.

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