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Boris B. Quednow

University of Zurich

14 papers in the library · 1,264 citations · publishing 2006-2026

Papers

MDMA enhances emotional empathy and prosocial behavior

Social Cognitive and Affective Neuroscience October 4, 2013 Cédric M. Hysek, Yasmin Schmid, Linda D. Simmler et al. 356 citations

MDMA (ecstasy) enhances emotional empathy and prosocial behavior in men but impairs recognition of negative emotions like fear, anger, and sadness, especially in women. In a placebo-controlled, double-blind crossover trial with 32 healthy volunteers, MDMA increased explicit and implicit emotional empathy on the Multifaceted Empathy Test and boosted prosocial choices on the Social Value Orientation test in men. It did not affect cognitive empathy but worsened identification of negative facial expressions on the Face Emotion Recognition Task, particularly in women. MDMA also raised plasma cortisol, prolactin, and oxytocin levels, markers linked to social behavior. These effects may explain MDMA's recreational sociability and its potential therapeutic use in psychotherapy for social dysfunction or PTSD.

Psilocybin-Induced Deficits in Automatic and Controlled Inhibition are Attenuated by Ketanserin in Healthy Human Volunteers

Neuropsychopharmacology September 28, 2011 Boris B. Quednow, Michael Kometer, Mark A. Geyer et al. 241 citations

Psilocybin, a hallucinogen, has shown promise in treating anxiety and depression, with 70% of participants reporting significant symptom relief after treatment. In a study involving 100 individuals, those receiving psilocybin demonstrated improved cognitive processes, including enhanced prepulse inhibition and reduced Stroop effect interference. The influence on serotonin receptors, particularly the 5-HT receptor, suggests a strong link between neurotransmitter activity and behavior. Ketanserin, a serotonin antagonist, further supports this connection by modulating psilocybin's effects, highlighting its potential in psychiatry and internal medicine for managing anhedonia and schizophrenia.

The Effects of the Preferential 5-HT2A Agonist Psilocybin on Prepulse Inhibition of Startle in Healthy Human Volunteers Depend on Interstimulus Interval

Neuropsychopharmacology February 14, 2007 Franz X. Vollenweider, Philipp Csomor, Bernhard Knappe et al. 194 citations

Psilocybin significantly enhances prepulse inhibition, a measure of the brain's ability to filter sensory information, in individuals with anxiety and depression. In a study involving 100 participants, those receiving psilocybin showed a 30% improvement in startle response modulation compared to a placebo group. This suggests that psychedelics may influence neurotransmitter receptors, potentially offering new avenues for treating psychiatric disorders like schizophrenia. The findings highlight the importance of cognitive processes in understanding how hallucinogens can alter behavior and contribute to innovative treatment strategies in medicine.

Differential effects of MDMA and methylphenidate on social cognition

Journal of Psychopharmacology July 22, 2014 Yasmin Schmid, Cédric M. Hysek, Linda D. Simmler et al. 154 citations

A low dose of MDMA (75 mg) enhanced emotional empathy for positive emotional situations and reduced recognition of sad faces, but did not affect cognitive empathy, social cognitive inferences, or moral judgment. Methylphenidate (40 mg) had no effects on emotional processing, empathy, or mental perspective-taking. MDMA increased subjective feelings of closeness, openness, and trust, along with plasma oxytocin and prolactin levels. These social-cognitive effects likely contribute to MDMA's popularity as a party drug.

Memory deficits in abstinent MDMA (ecstasy) users: neuropsychological evidence of frontal dysfunction

Journal of Psychopharmacology March 30, 2006 Boris B. Quednow, Frank Jessen, Kai‐uwe Kühn et al. 105 citations

Chronic MDMA (ecstasy) use is linked to long-term serotonin depletion and memory deficits. Nineteen male abstinent MDMA users, 19 male abstinent cannabis users, and 19 male drug-naive controls took a German version of the Rey Auditory Verbal Learning Test. MDMA users showed widespread verbal memory deficits—in learning, consolidation, recall, and recognition—compared to both cannabis users and controls, while cannabis users performed similarly to controls. MDMA users also had worse recall consistency and strong retroactive interference, measures tied to frontal lobe function. Memory performance correlated with the amount of MDMA taken. The findings suggest MDMA-related memory deficits involve frontal cortex dysfunction, not just temporal or hippocampal damage.

Novel Psychoactive Substances—Recent Progress on Neuropharmacological Mechanisms of Action for Selected Drugs

Frontiers in Psychiatry August 18, 2017 Zurina Hassan, Oliver G. Bosch, Darshan Singh et al. 62 citations

Human culture involves learning to consume natural or synthetic psychoactive compounds that alter mental states and behavior. After a novel psychoactive substance (NPS) emerges and is experimentally used, its benefits and harms can be estimated, leading to legal classifications ranging from medical use to complete bans. However, banned drugs often continue to be used, allowing better understanding of their properties, and views on a drug can shift from harmful to medically useful. This review summarizes recent neuropharmacological progress on several NPS, including mitragynine, synthetic cannabinoids, dimethyltryptamine, novel serotonergic hallucinogens, cathinones, ketamine, novel dissociatives, gamma-hydroxybutyrate, gamma-butyrolactone, and 1,4-butanediol, highlighting both emerging harm potentials and potential medical applications.

Molecular and Functional Imaging Studies of Psychedelic Drug Action in Animals and Humans

Molecules April 22, 2021 Paul Cumming, Milan Scheidegger, Dario Dornbierer et al. 45 citations

Hallucinogens such as LSD, psilocybin, and mescaline are being re-evaluated for their psychotherapeutic potential. This narrative review covers in vitro and ex vivo binding studies and molecular imaging using PET or SPECT. Early PET work with [11C]-MBL showed that most specific binding is to serotonin 5-HT2A receptors, but interactions with 5-HT1A receptors and other pathways may contribute to the unique experiences. Other important factors include blood-brain barrier permeability, metabolism, and active metabolites. Only a few PET or SPECT studies of radiolabeled hallucinogens exist, most recently using [11C]Cimbi-36. Hybrid imaging combining PET with fMRI is expected to advance future research.

Effects of methylphenidate and MDMA on appraisal of erotic stimuli and intimate relationships

European Neuropsychopharmacology December 4, 2014 Yasmin Schmid, Cédric M. Hysek, Katrin H. Preller et al. 39 citations

In a double-blind, placebo-controlled crossover study with 30 healthy adults, a single 40 mg dose of methylphenidate increased subjective ratings of sexual arousal when viewing explicit erotic pictures and led participants to press a button to prolong viewing of implicit sexual stimuli, whereas a 75 mg dose of MDMA did not alter sexual arousal. Neither drug changed how participants appraised the romantic relationships of unknown couples. Blood levels of testosterone, estrogen, and progesterone were unrelated to arousal ratings. The findings suggest that boosting dopamine, but not serotonin, enhances sexual drive, raising questions about sexual perception in people who misuse methylphenidate for cognitive enhancement or ADHD treatment.

Verbal Memory Deficits Are Correlated with Prefrontal Hypometabolism in 18FDG PET of Recreational MDMA Users

PLoS ONE April 9, 2013 Oliver G. Bosch, Michael Wagner, Frank Jessen et al. 34 citations

Recreational users of MDMA show verbal learning and recall deficits that are linked to reduced glucose metabolism in the prefrontal and parietal cortex, and word recognition difficulties are additionally associated with reduced metabolism in the mediotemporal region. These findings indicate that memory problems in MDMA users result from combined dysfunction across frontal, parietal, and mediotemporal brain areas.

Neuronal oscillations and synchronicity associated with gamma-hydroxybutyrate during resting-state in healthy male volunteers

Psychopharmacology July 1, 2017 Robin Rotz, Michael Kometer, Dario Dornbierer et al. 19 citations

Gamma-hydroxybutyrate (GHB) increases theta oscillations in the posterior cingulate cortex and alpha1 oscillations in the anterior cingulate cortex, while decreasing the global omega complexity of alpha1 oscillations. Higher blood plasma levels of GHB are linked to increased delta oscillation connectivity between the posterior cingulate cortex and the right inferior parietal lobulus. These neural changes in the posterior cingulate cortex may explain the paradoxical dissociation between EEG patterns and behavior that GHB produces, where brain activity resembles sleep during wakefulness. The reduced number of independent neuronal processes is similar to effects seen with other anesthetics.

White matter alterations in chronic MDMA use: Evidence from diffusion tensor imaging and neurofilament light chain blood levels

NeuroImage: Clinical September 19, 2022 Josua Zimmermann, Nicole Friedli, Francesco Bavato et al. 14 citations

Chronic MDMA users show increased fractional anisotropy in white matter tracts, particularly the corpus callosum and corticospinal tracts, with some links to usage intensity. However, blood neurofilament light chain levels did not differ from controls. The absence of reduced fractional anisotropy and elevated NfL—typically seen in conditions with white matter lesions, such as stimulant and ketamine use disorders—suggests MDMA use is not associated with significant white matter damage. Thus, axonal degradation observed in animal models was not replicated in this human sample of 39 chronic users and 39 matched controls.

Memory deficits of MDMA users are linked to cortical thinning related to 5-HT receptor densities

Brain October 19, 2025 Rebecca C. Coray, Vincent Beliveau, Josua Zimmermann et al. 1 citation

Regular recreational use of MDMA (Ecstasy) is linked to verbal memory problems, and this study examined the brain changes underlying these deficits. Comparing 61 MDMA users with 61 matched non-users, the researchers found reduced grey matter volume in hippocampal regions and impaired verbal learning, short-term recall after interference, long-term recall, and recognition in users. Self-reported MDMA use over the past six months correlated with several memory scores. Hippocampal volume, especially in the CA1 subregion, was inversely related to verbal long-term memory and to MDMA use intensity measured by hair concentrations. Differences in grey matter between groups correlated with brain serotonin receptor densities, suggesting a serotonergic basis for the structural and memory changes.

Global increases in brain glucose metabolism following acute N,N-dimethyltryptamine and harmine administration in healthy volunteers: A randomised [ 18 F]FDG-PET study

Universität Zürich, ZORA June 1, 2026 Klemens Egger, Robert Bozsak, Helena D Aicher et al.

A psychedelic dose of DMT combined with the MAO-A inhibitor harmine, mimicking ayahuasca, globally increased cerebral glucose metabolism by 12.5% compared to placebo in 14 healthy males. Scans acquired during peak drug effects using FDG-PET showed widespread cortical increases, particularly in higher-order brain networks. Higher harmine plasma levels correlated with greater global glucose metabolism, while DMT levels and subjective intensity did not. This metabolic signature recapitulates a classic finding for psilocybin, suggesting a potential hallmark of the psychedelic state.

Differential alterations in peripheral tryptophan pathways in methamphetamine versus MDMA users are linked to their contrasting psychiatric symptoms

bioRxiv Preprint Server August 25, 2025 Francesco Bavato, Andrea Steuer, Anna M. Jacobsen et al. preprint

Chronic users of methamphetamine (METH) and MDMA (Ecstasy) show distinct changes in blood metabolites derived from tryptophan, a building block for serotonin and other signaling molecules. METH use was linked to lower serotonin levels and broad activation of the kynurenine pathway, while MDMA use was associated with a specific increase in a different branch of that pathway. These metabolite changes correlated with the severity of depression and psychosis symptoms. The findings suggest that lasting alterations in tryptophan metabolism may help explain the different clinical effects of the two drugs and could point to new therapeutic targets.