Affective biases are important neuropsychological mechanisms by which emotions modulate cognition, behaviour and the subjective experience of mood. Previous studies have shown that the rapid-acting antidepressant, ketamine, and serotonergic psychedelic, psilocybin, modulate affective biases in a translational rat model. Both treatments differ from convention...
The classic psychedelic psilocybin elicits long-lasting neural plasticity and behavioral effects, but prior studies largely examined stress-naive animals. Using longitudinal imaging, we show that psilocybin increases dendritic spine density in frontal cortical neurons and facilitates fear extinction after chronic restraint stress, demonstrating psilocybin’s ...
Serotonergic psychedelics such as N,N-dimethyltryptamine (DMT) and 4-phosphoryloxy-N,N-dimethyltryptamine (psilocybin) show therapeutic promise for psychiatric and neurodegenerative disorders but may be limited by liabilities from serotonin (5-HT)-2A mediated psychoactive effects and potential cardiotoxicity via 5-HT2B activation. To address these limitation...
In the past year, the medical regulation of psilocybin-assisted therapy has expanded across additional international jurisdictions, requiring an update to the original medico-legal synthesis. Newly established or clarified regulatory pathways in New Zealand, Germany, Switzerland, the Czech Republic, and at the United States federal level reflect continued ev...
Psychedelics show therapeutic potential for treating psychiatric disorders. While studies have emphasized the roles of cortical pyramidal cells, GABAergic neurons also express serotonin receptors and are therefore likely targets of psychedelics. In this study, we determine the effect of psilocybin on the activity dynamics of major GABAergic cell types in the...
Abstract Rationale Clinical interest in psilocybin-assisted rehabilitation for motor disorders is growing. However, psilocybin’s motor effects are under-researched, and quantifying them is essential for assessing treatment risks and outcomes. Objectives This study aims to clarify whether acute effects of psilocybin disrupts established patterns of manual dex...
Aging is associated with chronic, low-grade inflammation (“inflammaging”), which contributes to neuropsychiatric and neurodegenerative disorders such as depression, Alzheimer’s disease, and Parkinson’s disease. Conventional pharmacotherapies often provide limited benefit in older adults and are further complicated by polypharmacy and drug-drug interactions. ...
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...
It is unclear how serotonin 2A receptors (5-HT2A Rs) in cortical layer 5 pyramidal neurons (L5 PyrNs) differentially contribute to psilocybin-induced hallucinations versus neuroplasticity. Here we show that psilocybin promotes synapse formation and maturation while accelerating the elimination of pre-existing synapses. Cell type-specific manipulation further...
Altered states of consciousness (ASC) represent a universal human capacity for accessing and transforming the subconscious mind, employed across cultures and millennia through diverse contemplative, somatic, pharmacological, ritual, and technological modalities. This comprehensive review synthesizes evidence from over 25 distinct disciplines spanning five cl...
This commentary critically examines the interpretation and analytic choices in Goodwin et al.’s (2026) analysis of therapeutic alliance in psilocybin treatment for treatment-resistant depression. While the authors conclude that alliance did not meaningfully contribute to treatment efficacy, we argue that this interpretation is not supported by the reported r...
Psilocybin can produce sustained benefits in affective and trauma-related disorders, yet if and how it reshapes sensory representations of learned valence associations remains largely unclear. To address this, we used longitudinal two-photon calcium imaging in awake C57BL/6 mice to examine how psilocybin modulates layer 2/3 auditory cortex activity at single...
Background: Psilocybin-assisted therapy (PAT) has shown promise for alcohol use disorder (AUD) in randomized controlled trials (RCTs). However, the effects of open-label administration following blinded treatment are unclear. Here, we present safety and efficacy data from an open-label extension of a Phase II RCT (NCT02061293) examining PAT for AUD. Methods:...
Serotonergic psychedelics have attracted considerable interest as promising therapeutic agents. However, the molecular mechanisms linking their acute hallucinogenic-like effects to longer-lasting neuroplastic responses remain incompletely understood, partly because of the scarcity of native neural models suitable for mechanistic studies. Here, we developed a...
BACKGROUND: New legal frameworks for supervised psychedelic services are emerging, with Oregon and Colorado implementing programs to train and license psilocybin facilitators. This study describes Oregon's early psilocybin facilitator workforce and assesses state-approved training programs. METHODS: The Open Psychedelic Evaluation Nexus (OPEN) reviewed Orego...
Abstract Depression and anxiety affect one in five adults, with age affecting prevalence. While clinical trials suggest classic psychedelics (e.g., psilocybin, LSD) and non-classic psychedelics (e.g., MDMA, ketamine) may alleviate these symptoms, it remains unclear how these relationships function in naturalistic settings or how they vary across the lifespan...
Psilocybin has antidepressant effects, but its 5-HT2 AR-mediated perceptual effects limit tolerability. We combined psilocybin with a phosphodiesterase-9 inhibitor (PDE9i) and observed suppression of head-twitch response, but maintenance of antidepressant-like behavior. Proteomics showed that PDE9i-psilocybin reduced 5-HT2 AR-mediated pathways while enhancin...
Abstract Background: This case describes a substance-induced manic episode with psychotic features in which interaction with an AI (artificial intelligence) chatbot appeared to corroborate and reinforce the patient’s delusional thought content and to contradict medical advice. Excerpts from the patient’s interactions with the AI chatbot provide novel clinica...
Psilocybin, a serotonergic psychedelic, can produce rapid and enduring antidepressant effects in patients with major depressive disorder (MDD)[1, 2], yet the neural mechanisms underlying these effects remain unclear. Negative affective biases are an important neuropsychological mechanism central to the development and perpetuation of MDD[3]. Using a translat...
Rationale: Ego-dissolution represents a key therapeutic mechanism in psychedelic-assisted therapy, yet current measurement approaches may inadequately capture its multidimensional nature. Objective: To develop and validate the Multidimensional Ego-Dissolution Assessment (MEDA) and examine substance-specific patterns across classical psychedelics. Methods: It...
