A prominent theory of psychedelics is that they increase brain entropy. Thirteen studies have evaluated psychedelic effects on fMRI brain entropy, each applying a distinct measure. Here we evaluated these metrics in an independent 28-participant healthy cohort with 121 pre- and post-psilocybin fMRI scans. We assessed relations between brain entropy and objec...
BACKGROUND: Patients with chronic cluster headache (CCH) suffer from poor sleep, which may impact their brain microstructure and parenchymal clearance of waste products. Psilocybin has shown promise for the treatment of CCH and has been linked to increased neuroplasticity with possible influences on brain microstructure. AIMS: To investigate the effects of p...
Psilocybin and other serotonergic drugs acutely alter human brain function and large-scale connectivity as measured with BOLD fMRI, but whether these effects are frequency-specific remains unknown. We applied multitaper spectral and cross-spectral analyses to resting-state fMRI data from 28 healthy volunteers scanned multiple times acutely following oral psi...
Background Recent studies have suggested that psychedelics such as lysergic acid diethylamide (LSD) and psilocybin might benefit patients with mental illness. This revival calls for revisiting the field’s past experiences with these agents. From 1960 to 1973, many patients were treated with LSD and/or psilocybin at the Department of Psychiatry at Frederiksbe...
In this study, we provide the first study to integrate molecular and functional neuroimaging during psychedelic drug effects in humans. Using simultaneous PET-MRI technology, we describe multiple brain actions of lysergic acid diethylamide (LSD) in healthy volunteers. We quantify the occupancy of LSD at cerebral serotonin 2A receptors and show that LSD incre...
Understanding neuromodulatory effects of serotonin 2A receptor (5-HT2A R) agonists with diverse pharmacological profiles is relevant to advancing psychedelic-related drug applications. We performed simultaneous positron emission tomography (PET) and pharmacological magnetic resonance imaging (phMRI) in anesthetized nonhuman primates (NHP; N = 3) to examine p...
Motivation: Acute effects of psychedelic drugs are under-reported in neuroimaging studies, warranting further investigation of their immediate pharmacology to explore the potential to monitor treatment response with imaging. Goal(s): Our goal was to assess acute impacts of serotonergic (psychedelic and non-psychedelic) agonists on hemodynamics in non-human p...
Psilocin, the active metabolite of psilocybin, is a psychedelic and agonist at the serotonin 2A receptor (5-HT2AR) that has shown positive therapeutic effects for brain disorders such as depression. To elucidate the brain effects of psilocybin, we directly compared the acute effects of 5-HT2AR agonist (psilocybin) and antagonist (ketanserin) on cerebral bloo...
Abstract Objective To evaluate the feasibility and prophylactic effect of psilocybin as well as its effects on hypothalamic functional connectivity (FC) in patients with chronic cluster headache (CCH). Background CCH is an excruciating and difficult-to-treat disorder with incompletely understood pathophysiology, although hypothalamic dysfunction has been imp...
The serotonergic psychedelic psilocybin acutely induces changes in emotional states. However, it remains unresolved whether psilocybin acutely modulates emotionally-relevant amygdala reactivity to emotions, a brain region critically involved in emotion processing. Using functional magnetic resonance imaging (fMRI), we examined in 26 healthy individuals wheth...
Functional magnetic resonance imaging (fMRI) is increasingly used to non-invasively study the acute impact of psychedelics on the human brain. While fMRI is a promising tool for measuring brain function in response to psychedelics, it also has known methodological challenges. We conducted a systematic review of fMRI studies examining acute responses to exper...
Psilocybin and other serotonergic psychedelics have re-emerged as therapeutics for neuropsychiatric disorders, including addiction. Psilocybin induces long-lasting effects on behavior, likely due to its profound ability to alter consciousness and augment neural connectivity and plasticity. Impaired synaptic plasticity in obesity contributes to 'addictive-lik...
Chronic cluster headache (CCH) is an excruciating disorder of unknown pathophysiology, but hypothalamic dysfunction has been implicated. CCH is difficult to treat but on a case-basis, the psychedelic compound psilocybin is said to have beneficial effects. In this first-ever clinical trial ( NCT04280055 ), we evaluate in a small open-label study of CCH patien...
BackgroundNew research has suggested the clinical use of lysergic acid diethylamide (LSD) and psilocybin in selected patient populations. However, concerns about the clinical use of LSD were advanced in a large Danish follow-up study that assessed 151 LSD-treated psychiatric patients approximately 25 years after their treatment in the 1960s.AimsThe purpose o...
