Lukas A. Basedow, PhD candidate

TU Dresden

Neuropsychological Functioning after Chronic Use of Serotonergic Psychedelics – A Systematic Review and Meta-Analysis


Serotonergic psychedelics induce altered states of consciousness, and there is converging evidence that they acutely reduce neuropsychological performance. Unfortunately, little is known about the relationship between the chronic use of these substances and persistent neuropsychological changes. Research with MDMA and cannabis suggests that substances, which alter acute neuropsychological functioning, might also induce impairments after chronic use. Based on this line of research, and studies detailing acute reduction of performance induced by serotonergic psychedelics, we hypothesized that chronic use of these substances is associated with impaired neuropsychological functioning. To test this hypothesis, we conducted a systematic review and meta-analysis, including studies that reported at least one neuropsychological measurement in chronic users of serotonergic psychedelics. I will discuss the detailed results of the studies we included, the overall pattern of neuropsychological functioning we could detect, the results of our meta-analytic calculations, and the conclusions we can draw about persistent neuropsychological changes after chronic use of serotonergic psychedelics. Finally, I will point out which open questions remain, and suggest ways of dealing with methodological hurdles that are common in this type of research. The results of this project are valuable for practitioners, scientists, and everyone else who works with, is interested in, or regularly uses serotonergic psychedelics.


Lukas is a PhD student and psychologist, mainly working in the field of adolescent substance abuse at the medical faculty of the TU Dresden, in Dresden, Germany. Previously he was involved in psychedelic research projects under the supervision of Dr. Kim Kuypers at the University of Maastricht and Dr. Tomislav Majić at the research group “Psychotropic Substances” in Berlin. He has also been a volunteer staff member in the science committee of MIND – the European Foundation for Psychedelic Science, since November 2017. Additionally, Lukas volunteers in harm reduction services offering support during difficult, drug-induced experiences in the context of parties and festivals.



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