Acta Psychiatrica Scandinavica
September 21, 2017
Felix Müller, Claudia Lenz, Patrick C. Dolder et al.
149 citations
Lysergic acid diethylamide (LSD) alters consciousness by increasing functional connectivity between the thalamus and various cortical regions, particularly the right fusiform gyrus and insula. In 20 healthy participants given 100 μg LSD orally, thalamic connectivity changes correlated with subjective auditory and visual drug effects. These findings suggest that hallucinogenic effects may arise from enhanced cortical excitability through thalamocortical interactions, providing insight into the role of the 5-HT2A receptor in altered states of consciousness.
Translational Psychiatry
April 4, 2017
Felix Mueller, Claudia Lenz, Patrick C. Dolder et al.
124 citations
Lysergic acid diethylamide (LSD) reduces reactivity in the left amygdala and right medial prefrontal cortex when processing fearful faces, compared to a placebo. In a double-blind, randomized, crossover study, 20 healthy adults received either 100 μg of LSD or a placebo before undergoing functional magnetic resonance imaging (fMRI). Plasma LSD levels were measured before and after the scan. A significant negative correlation emerged between the reduced amygdala response to fearful stimuli and the subjective drug effects reported by participants. These findings indicate that LSD alters the engagement of brain regions involved in emotional processing.
Neuroscience & Biobehavioral Reviews
December 30, 2015
Felix Mueller, Claudia Lenz, Markus Steiner et al.
68 citations
Moderate use of MDMA (ecstasy) shows no convincing evidence of structural or functional brain alterations in neuroimaging studies. A review of 19 studies, each involving subjects with fewer than 50 lifetime episodes or under 100 tablets consumed, found no significant harmful effects. However, the lack of results is linked to high methodological variability in dosages and co-consumption of other drugs, low study quality, and small sample sizes.
Psychological Medicine
October 2, 2017
André Schmidt, Felix Müller, Claudia Lenz et al.
62 citations
Activating the serotonin 2A receptor with LSD impairs the brain's ability to stop or inhibit responses, and this breakdown is linked to visual hallucinations. In a double-blind, placebo-controlled experiment with 18 healthy adults, LSD reduced brain activity in regions including the frontal and cingulate cortex, middle temporal gyrus, and cerebellum during a response-inhibition task. Parahippocampal activation related differently to performance under LSD versus placebo. Less activation in the left superior frontal gyrus during LSD exposure was associated with greater cognitive impairment and visual imagery. The findings suggest that 5-HT2A receptor activation disrupts hippocampal-prefrontal circuits, which may promote visual hallucinations.