Human neuroimaging with functional Magnetic Resonance Imaging has been a key feature of the current wave of psychedelic research, in both healthy and clinical populations. The available data has suggested that classic psychedelics (psilocybin, LSD, DMT) have a characteristic effect of acutely and profoundly disrupting the normal pattern of resting-state conn...
Psilocybin is a psychedelic serotonergic compound that is renowned for its potent psychoactive effects. Over the past 15 years, an increasing number of controlled clinical trials showed that it has a fast-acting and sustainable efficacy in treating various psychiatric disorders. Neuroimaging studies have been conducted with the objective of elucidating the n...
This chapter reviews the effects of classic psychedelics on human oscillatory brain activity, as measured by resting-state electroencephalography (EEG) and magnetoencephalography (MEG). Across moderate to high doses of LSD, psilocybin, ayahuasca, and DMT, a consistent reduction in alpha power (8-13 Hz) emerges, particularly in occipital regions. Below 30 Hz,...
Psychiatric disorders are marked by habitual patterns of thought, emotion, and behavior, and many mental health disorders are resistant to standard treatments (1)(2)(3)(4). For example, symptoms of major depressive disorder include ruminative negative thoughts, pervasive sadness, and lack of goaldirected behavior (5)(6)(7). Similarly, many anxiety and trauma...
Psilocybin produces an altered state of consciousness in humans and is associated with complex spatiotemporal changes in cortical networks. Given the emphasis on rodent models for mechanistic studies, there is a need for characterization of the effect of psilocybin on cortex-wide network dynamics. Previous electroencephalographic studies of psychedelics in r...
Psychedelics can profoundly alter consciousness by reorganising brain connectivity; however, their effects are context-sensitive. To understand how this reorganisation depends on context, we collected and comprehensively analysed the largest psychedelic neuroimaging dataset to date. Sixty-two adults were scanned with functional MRI and EEG during rest and na...
Major Depressive Disorder (MDD) is typically characterized by altered linear functional connectivity (FC) across large-scale brain networks. Yet, it is unclear whether similar alterations are observed when nonlinear FC is examined. This study investigated how antidepressant treatment (i.e., psilocybin and escitalopram) modulates both linear FC and nonlinear ...
Psilocybin is a hallucinogen with complex neurobiological and behavioral effects. This is the first study to use MRI to follow functional changes in brain activity in response to different doses of psilocybin in fully awake, drug naive rats. Female and male rats were given IP injections of vehicle or psilocybin in doses of 0.03 mg/kg, 0.3 mg/kg, and 3.0 mg/k...
Repetitive mild head injuries incurred while playing organized sports, during car accidents and falls, or in active military service are a major health problem. These head injuries induce cognitive, motor, and behavioral deficits that can last for months and even years with an increased risk of dementia, Parkinson’s disease, and chronic traumatic encephalopa...
ABSTRACT BACKGROUND AND PURPOSE: There is surging interest in the therapeutic potential of psychedelic compounds like psilocybin in the treatment of psychiatric illnesses like major depressive disorder (MDD). Recent studies point to the rapid antidepressant effect of psilocybin; however, the biological mechanisms underlying these differences remain unknown. ...
Psychedelics, historically celebrated for their cultural and spiritual significance, have emerged as potential breakthrough therapeutic agents due to their profound effects on consciousness, emotional processing, mood, and neural plasticity. This review explores the mechanisms underlying psychedelics' effects, focusing on their ability to modulate brain conn...
Neural representation can extend beyond localised activity to encompass global patterns, where information is distributed across brain networks in a hierarchical manner. Recent research suggests that the hierarchy of causal influences shaping these patterns can serve as a signature of distinct brain states, with implications for neuropsychiatric disorders. H...
Serotonergic psychedelics induce altered states of consciousness and have shown potential for treating a variety of neuropsychiatric disorders, including depression and addiction. Yet their modes of action are not fully understood. Here, we provide a novel, synergistic understanding of psychedelics arising from systematic reviews and meta-analyses of three h...
This study aims to investigate the effects of oral psilocybin on OCD symptomatology and provide the first evidence of the neural mechanism that may mediate psilocybin's purported therapeutic effects on OCD. Aim 1: To investigate the effects of psilocybin on OCD symptomatology. OCD symptom severity will be assessed before treatment and 24 and 48 hours after t...
Psilocybin has been shown to induce fast and sustained improvements in mental well-being across various populations, yet its long-term mechanisms of action are not fully understood. Initial evidence suggests that longitudinal functional and structural brain changes implicate fronto-striatal-thalamic (FST) circuitry, a broad system involved in goal-directed b...
"Iracema comes with the pot full of the green liquor. The shaman decrees the dreams to each warrior and distributes the wine of jurema, which carries the brave Tabajara to heaven." José de Alencar, in his poetic novel “Iracema” (1865)1. IntroductionThe "wine of jurema", used in ancient Brazilian shamanic rituals, is rich in N,N-dimethyltryptamine (DMT), a na...
As psychedelic-assisted psychotherapy gains momentum, clinical investigation of next-generation psychedelics may lead to novel compounds tailored for specific populations. 2,5-dimethoxy-4-bromophenethylamine (2C-B) is a psychedelic phenethylamine reported to produce less dysphoria and subjective impairment than the psychedelic tryptamine psilocybin. Despite ...
Body dysmorphic disorder (BDD) is a severe psychiatric condition characterized by preoccupation with perceived flaws in one's appearance, which the individual views as defective or ugly. Psilocybin, a serotonin 2A receptor agonist with psychedelic properties, has emerged as a potential therapeutic agent for depression and other psychiatric disorders. This st...
