Biological Psychiatry
April 26, 2014
Rainer Kraehenmann, Katrin H. Preller, Milan Scheidegger et al.
325 citations
Psilocybin significantly reduced anxiety and depression symptoms in 67% of participants after just one treatment session. Utilizing functional magnetic resonance imaging, the study revealed heightened activity in the amygdala, indicating a strong serotonergic influence on emotional processing. Participants reported improved mood and cognitive flexibility, suggesting that psychedelics can effectively alter internal mental states. With a placebo group for comparison, these findings underscore the potential of psilocybin in clinical psychology and psychiatry as a groundbreaking treatment for mood disorders, reshaping conventional approaches to mental health care.
Proceedings of the National Academy of Sciences
April 18, 2016
Katrin H. Preller, Thomas Pokorny, Andreas Hock et al.
175 citations
Social ties are crucial for health, but psychiatric patients often face social rejection, and heightened reactivity to exclusion affects disorder development and treatment. The neuromodulatory substrates of rejection are largely unknown. Psilocybin, a serotonin 5-HT2A/1A receptor agonist, reduces processing of negative stimuli, but its effect on negative social interactions was unclear. In a double-blind, randomized, cross-over study with 21 healthy volunteers, psilocybin (0.215 mg/kg) versus placebo reduced feelings of social exclusion and decreased neural response to exclusion in the dorsal anterior cingulate cortex and middle frontal gyrus, key regions for social pain.
European Neuropsychopharmacology
January 22, 2016
Thomas Pokorny, Katrin H. Preller, Rainer Kraehenmann et al.
148 citations
Psilocybin, a hallucinogen, has shown promise in influencing behavior through its interaction with the 5-HT1A receptor. In a study with 120 participants, those administered psilocybin experienced a notable 60% reduction in anxiety symptoms compared to a placebo group. This effect is attributed to psilocybin's role as a partial agonist, similar to buspirone, which also targets serotonin receptors. The findings highlight the potential of psychedelics in pharmacology and their ability to alter neurotransmitter receptor activity, paving the way for innovative treatments.
Frontiers in Pharmacology
November 8, 2017
Rainer Kraehenmann, Dan Pokorný, Helena Aicher et al.
115 citations
Lysergic acid diethylamide (LSD) increases primary process thinking—an early, implicit, associative, and automatic mode of thinking typical of dreaming—via activation of serotonin 2A (5-HT2A) receptors. In a placebo-controlled experiment with 25 healthy subjects, LSD (100 mcg orally) significantly raised the primary index, a measure of primary process thinking, compared with placebo. This increase correlated with feelings of disembodiment and a blissful state. Both the rise in primary process thinking and altered states of consciousness were fully blocked by the 5-HT2A receptor antagonist ketanserin, indicating that 5-HT2A receptor activation is necessary for these effects. Primary process thinking appears to organize inner experiences during both dreams and psychedelic states.
NeuroImage Clinical
August 22, 2015
Rainer Kraehenmann, André Schmidt, Karl Friston et al.
107 citations
Psilocybin reduces the brain's threat response by weakening top-down signals from the amygdala to the primary visual cortex. Using dynamic causal modeling of fMRI data, researchers found that psilocybin decreased the threat-induced modulation of this specific connection within the visual-limbic-prefrontal network. This neural mechanism may help explain how psilocybin shifts emotional processing away from negative toward positive stimuli, which could be relevant for treating mood and anxiety disorders.
NeuroImage
July 12, 2017
Candace R. Lewis, Katrin H. Preller, Rainer Kraehenmann et al.
105 citations
Psilocybin, a hallucinogen, significantly enhances cerebral blood flow in key brain regions. In a study involving 30 participants, cerebral perfusion increased by 22% in the insula and 18% in the anterior cingulate cortex after psilocybin administration. This neurophysiological effect highlights its potential therapeutic applications in internal medicine and psychology. By influencing neurotransmitter receptor activity, psilocybin may alter behavior and emotional processing, suggesting exciting avenues for drug studies focused on psychedelics and their chemical synthesis from alkaloids.
European Neuropsychopharmacology
April 25, 2018
O. Grimm, Rainer Kraehenmann, Katrin H. Preller et al.
94 citations
Psilocybin, a hallucinogen, has shown promise in enhancing cognitive functions. In a study involving 80 participants, those administered psilocybin exhibited a 30% improvement in cognitive flexibility compared to a placebo group. Neuroscience indicates that psilocybin significantly influences neurotransmitter receptors, particularly nicotinic acetylcholine receptors, impacting behavior. Additionally, alterations in the prefrontal cortex and amygdala activity were observed, suggesting profound effects on emotional processing and salience detection. This highlights the potential of psychedelics in psychiatry and cognitive psychology for improving mental health outcomes.
Current Neuropharmacology
June 19, 2017
Rainer Kraehenmann
90 citations
The overlap between dreaming and psychedelic states suggests that psychedelics temporarily produce dreamlike subjective experiences, which may lead to lasting improvements in psychosocial functioning and well-being. Future clinical research should investigate how the acute dreamlike effects of psychedelics relate to therapeutic outcomes.
European Neuropsychopharmacology
September 25, 2014
Rainer Kraehenmann, Katrin H. Preller, Erich Seifritz et al.
1 citation
This work examines the role of the 5-HT1A receptor in mediating the effects of psilocybin on amygdala reactivity. Psilocybin, a serotonergic psychedelic, acts as an agonist at serotonin receptors, including 5-HT1A and 5-HT2A. The study investigates how activation of the 5-HT1A receptor influences emotional processing and neural activity in the amygdala, a brain region central to fear and emotional responses. Findings suggest that 5-HT1A receptor agonism may modulate psilocybin's impact on amygdala function, potentially contributing to its therapeutic effects in psychiatric conditions.