Serotonergic psychedelics show therapeutic potential across neuropsychiatric disorders despite transient acute effects. These compounds share serotonin 2 A receptor agonism but differ in broader pharmacology, motivating a systematic comparison of their neurobiological effects. Here, we use [18 F]FDG-PET in rats to assess acute and one-week effects of psilocybin, LSD, and 2C-B on brain metabolic...
Background and objective: Anxiety disorders are among the most prevalent psychiatric disorders worldwide and affect all age groups. Current pharmacological treatments, such as selective serotonergic reuptake inhibitors (SSRI’s) and benzodiazepines, have limitations in terms of adverse effects and efficacy, which highlights the need for alternative therapies. Serotonergic psychedelics have...
PsyArXivMay 14, 2026Jacob Cohen, Peter Parbo, Per Trads Ørskov et al.
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Background: Social anxiety disorder is a chronic and disabling condition with limited response to standard therapies. Low-dose psilocybin may enhance the effectiveness of exposure-based treatments by modulating neural circuits associated with fear and avoidance. Virtual reality exposure therapy offers a controlled and individualized platform for intervention. Objective: This phase 2b,...
Mammalian brain may contain an endogenous pool of the psychedelic substance N,N-dimethyltryptamine (DMT), which may act as a co-transmitter with serotonin (5-HT). We tested the joint hypotheses. We tested the joint hypotheses that endogenous DMT would accumulate in rat brain after inhibiting monoamine oxidase with pargyline, whereas its acidic metabolite 3-indoleacetic acid (3-IAA) would...
Mammalian brain may contain an endogenous pool of the psychedelic substance N,N-dimethyltryptamine (DMT), which may act as a co-transmitter with serotonin (5-HT). We tested the joint hypotheses. We tested the joint hypotheses that endogenous DMT would accumulate in rat brain after inhibiting monoamine oxidase with pargyline, whereas its acidic metabolite 3-indoleacetic acid (3-IAA) would...
Introduction: Cognitive flexibility is essential for behavioral adaptation in response to environmental changes and is impaired in various neuropsychiatric disorders. The serotonergic psychedelic psilocybin has shown potential in enhancing cognitive flexibility, although with mixed results. In this study, we investigated the effects of psilocybin on cognitive flexibility in rats using a...
Obsessive-Compulsive Disorder (OCD) can present significant challenges to individuals mental health, characterized by intrusive thoughts and repetitive maladaptive behaviors. Recent research into alternative treatments has highlighted psychedelics, notably psilocybin, for their potential therapeutic benefits in various psychiatric disorders, including OCD. This case study evaluated the impact...
IntroductionCognitive flexibility is essential for adapting behavior in response to environmental changes and is implicated in various neuropsychiatric disorders. Psilocybin, a serotonergic psychedelic, has shown potential in enhancing cognitive flexibility, though results are mixed. This study investigates the effects of psilocybin on cognitive flexibility using a three-choice visual reversal...
Background: Obsessive-Compulsive Disorder (OCD) presents significant challenges to individuals mental health, characterized by intrusive thoughts and repetitive maladaptive behaviours. Recent exploration into alternative treatments has spotlighted psychedelics, notably psilocybin, for their potential therapeutic benefits in different psychiatric disorders, including OCD. This case study delves...
Serotonergic psychedelic drugs have shown promising benefits in trials for various neuropsychiatric disorders. While the acute effects of these psychedelics last only a few hours, the positive therapeutic effects can persist long after a single administration. Serotonergic psychedelics produce their psychedelic effects by activating serotonin 2A receptors, but they differ in other...
Serotonergic psychedelics, such as psilocybin and LSD, have garnered significant attention in recent years for their potential therapeutic effects and unique mechanisms of action. These compounds exert their primary effects through activating serotonin 5-HT2A receptors, found predominantly in cortical regions. By interacting with these receptors, serotonergic psychedelics induce alterations in...
Psilocybin (a classic serotonergic psychedelic drug) has received appraisal for use in psychedelic-assisted therapy of several psychiatric disorders. A less explored topic concerns the use of repeated low doses of psychedelics, at a dose that is well below the psychedelic dose used in psychedelic-assisted therapy and often referred to as microdosing. Psilocybin microdose users frequently report...
RationaleThe psychedelic effects of the traditional Amazonian botanical decoction known as ayahuasca are attributed to the effects of N,N-dimethyltryptamine (DMT) at brain serotonin 5-HT2A receptors. To make oral DMT bioavailable, ayahuasca additionally contains reversible monoamine oxidase A (MAO-A) inhibitors, namely β-carboline alkaloids such as harmine. However, there is lacking biochemical...
Rationale: The psychedelic effects of the traditional Amazonian botanical decoction known as ayahuasca are often attributed to agonism at brain serotonin 5-HT2A receptors by N,N-dimethyltryptamine (DMT). To reduce first pass metabolism of oral DMT, ayahuasca preparations additionally contain reversible monoamine oxidase A (MAO-A) inhibitors, namely β-carboline alkaloids such as harmine....
Molecular PsychiatryJanuary 10, 2022Xiu-Li Zhao, Annika B. Ozols, K. Meyers et al.
Serotonin 2A receptors (5-HT2ARs) mediate the hallucinogenic effects of psychedelic drugs and are a key target of the leading class of medications used to treat psychotic disorders. These findings suggest that dysfunction of 5-HT2ARs may contribute to the symptoms of schizophrenia, a mental illness characterized by perceptual and cognitive disturbances. Indeed, numerous studies have found that...
Hallucinogens are a loosely defined group of compounds including LSD, N,N-dimethyltryptamines, mescaline, psilocybin/psilocin, and 2,5-dimethoxy-4-methamphetamine (DOM), which can evoke intense visual and emotional experiences. We are witnessing a renaissance of research interest in hallucinogens, driven by increasing awareness of their psychotherapeutic potential. As such, we now present a...
The remarkable effects exhibited by classical psychedelics in recent clinical trials have spawned considerable interest in 5-HT2A receptor (5-HT2AR) activation as a treatment strategy for several psychiatric/cognitive disorders. In this study we have continued our development of 25CN-NBOH, one of the most 5-HT2AR-selective agonists reported to date, as a pharmacological tool for exploration of...
bioRxiv Preprint ServerFebruary 23, 2020X. Zhao, K. T. Meyers, Andrew McBride et al.1 citation
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Serotonin 2A receptors (5-HT2ARs) mediate the effects of hallucinogenic drugs and antipsychotic medications, and are reduced in schizophrenia patients’ brains. However, the mechanisms that regulate 5-HT2AR expression remain poorly understood. We show that an environmental stimulus, sleep deprivation, upregulates 5-HT2ARs in the mouse frontal cortex (FC) in just 6-8 hours. This induction...
UNLABELLED: PET brain imaging of the serotonin 2A (5-hydroxytryptamine 2A, or 5-HT(2A)) receptor has been widely used in clinical studies, and currently, several well-validated radiolabeled antagonist tracers are used for in vivo imaging of the cerebral 5-HT(2A) receptor. Access to 5-HT(2A) receptor agonist PET tracers would, however, enable imaging of the active, high-affinity state of...