Psychedelic Therapy, Positive Emotional Experiences, and the Central Role of Self-Compassion.

Psychedelics can acutely induce mystical experiences and elevated positive mood, which may contribute to the potential benefits of psychedelic therapy. However, there remains limited understanding of the occurrence and importance of specific positive emotional experiences within psychedelic therapy. Therefore, we examined the effects of psychedelics on positive emotional experiences and their association with improvements in mental health.

Improved mental health outcomes and normalised spontaneous EEG activity in veterans reporting a history of traumatic brain injuries following participation in a psilocybin retreat.

Introduction: Psilocybin, a serotonergic psychedelic, has shown therapeutic potential in treating mental health disorders by, amongst the many effects, promoting neuroplasticity and reorganising functional connectivity across cortical and subcortical networks involved in emotion and cognition. Veterans with traumatic brain injuries (TBI) often experience chronic neurological and psychological symptoms such as post-traumatic stress disorder (PTSD) and depression. This study investigates the effects of psilocybin administered in retreat settings on veterans with a history of TBI, focusing on mental health outcomes and changes in brain connectivity as measured by EEG.

Perturbing whole-brain models of brain hierarchy: An application for depression following pharmacological treatment.

Determining the scale of neural representations is a central challenge in neuroscience. While localized representations have traditionally dominated, evidence suggests information is also encoded in distributed, hierarchical networks. Recent research indicates that the hierarchy of causal influences shaping functional patterns serves as a signature of distinct brain states, with implications for neuropsychiatric disorders.

The role of GABA, glutamate, and Glx levels in treatment of major depressive disorder: A systematic review and meta-analysis.

This systematic review and meta-analysis aims to explore a possible role of gamma-aminobutyric acid (GABA) and glutamate, as measured by Magnetic Resonance Spectroscopy (MRS), in the treatment outcomes of people with Major Depressive Disorder (MDD). Despite the prevalence of MDD and various treatment modalities, the neurobiological mechanisms of each remain poorly understood. We synthesised data from 41 longitudinal studies comprising 918 individuals with MDD, spanning four primary treatment modalities: selective serotonin reuptake inhibitors (SSRIs), ketamine, repetitive transcranial magnetic stimulation (rTMS), and electroconvulsive therapy (ECT).

An investigation of acute physiological and psychological moderators of psychedelic-induced personality change among healthy volunteers.

This study investigated the effects of a single high-dose of psilocybin on personality traits in psychedelic-naïve healthy volunteers. These data originate from a larger within-subjects fixed-order design trial, where a single high dose of psilocybin (25 mg) was administered in a psychologically supportive setting and was compared against a (one-month) prior, 1 mg 'placebo' dose. Personality shifts were assessed by the Big Five Inventory and the Big Five Aspect Scale, while the Altered States of Consciousness questionnaire (5D-ASC) and the Psychological Insight Scale gauged the acute psychological effects of the substance.

Single-dose (10 mg) psilocybin reduces symptoms in adults with obsessive-compulsive disorder: A pharmacological challenge study.

Background: Obsessive-compulsive disorder (OCD) is a common and disabling condition. A large proportion of patients fail to respond to first-line treatment with serotonin reuptake inhibitors either selective serotonin reuptake inhibitors (SSRIs) or clomipramine. Preliminary evidence suggests psilocybin, a serotonin receptor agonist, might be efficacious.

The effects of psilocybin therapy versus escitalopram on cognitive bias: A secondary analysis of a randomized controlled trial.

Background: Patients with Major Depressive Disorder (MDD) have more dysfunctional attitudes than healthy individuals and these pessimistic biases are correlated with depression severity. Psilocybin has demonstrated sustained remission in depression.

Methods: Secondary analysis of a two-arm randomized controlled trial assessing the effect of psilocybin therapy versus escitalopram on 'maladaptive' cognitive biases relevant to the construct of depression.

Enhanced meaning in life following psychedelic use: converging evidence from controlled and naturalistic studies.

Introduction: Psychedelics, such as psilocybin, are increasingly recognized for their propensity to elicit powerful subjective experiences that carry personal meaning. While research has demonstrated the capacity for these compounds to promote psychological wellbeing, it has yet to be shown to what extent they modulate "meaning in life", a specific contributor to mental and physical health.

Methods: Using the Meaning in Life Questionnaire (MLQ), we examined changes in meaning in life occurring across three different contexts of psychedelic use, including a randomized clinical trial of psilocybin for depression, controlled administration of psilocybin in a single-arm healthy volunteer study, and a naturalistic observational study following participants in psychedelic retreats.

The Music for Subanesthetic Infusions of Ketamine randomised clinical trial: ketamine as a psychedelic treatment for highly refractory depression.

Background: Ketamine exerts potent but transient antidepressant effects in treatment-resistant depression (TRD). Combinations of ketamine and psychotherapy have attracted interest, but no trial has investigated a psychedelic model of ketamine-psychotherapy for TRD to our knowledge.

Aims: This secondary analysis of a randomised clinical trial (RCT) explores the therapeutic effects and experiential mechanisms of the Montreal Model of ketamine-psychotherapy for TRD, with or without music.

A model training curriculum for psychedelic, psycholytic, and entactogen-assisted psychotherapy.

The authors offer a model for curriculum for education and training in substance-assisted psychotherapy (SAP), that is, psychedelic, psycholytic, and entactogen/MDMA (3,4-methylenedioxymethamphetamine)-assisted psychotherapy, addressing both the detailed contents of training and the question of experiential training. All authors of this model have an abiding interest and extensive experience in both the theory and practical aspects of SAP and questions relating to training. The model curriculum has been written through an international consensus building process and represents a consensus statement about the topic.

Reduced Brain Responsiveness to Emotional Stimuli With Escitalopram But Not Psilocybin Therapy for Depression.

Objective: Psilocybin is an emerging intervention for depression that may be at least as effective as selective serotonin reuptake inhibitors (SSRIs), but effects of the two treatments on the neural correlates of emotional processing have never been directly compared.

Methods: The authors assessed neural responses to emotional faces using blood-oxygen-level-dependent (BOLD) functional MRI (fMRI) in two groups with major depression. One group (N=25; 9 women and 16 men) received two dosing sessions with 25 mg psilocybin plus 6 weeks of daily inert placebo, and the second group (N=21; 6 women and 15 men) received 6 weeks of escitalopram plus two dosing sessions with a nonpsychoactive (placebo) dose of 1 mg psilocybin.

Dissociable effects of psilocybin and escitalopram for depression on processing of musical surprises.

Psilocybin therapy (PT) is emerging as an effective intervention for Major Depressive Disorder (MDD), offering comparable efficacy to conventional treatments like selective serotonin reuptake inhibitors (SSRIs). Music, an emotionally evocative stimulus, provides a valuable tool to explore changes in hedonic and predictive processing mechanisms via expectancy violations, or 'surprises'. This study sought to compare behavioural and functional magnetic resonance imaging (fMRI) responses to musical surprises in MDD patients treated with either PT or the SSRI, escitalopram.

Exploring 5-MeO-DMT as a pharmacological model for deconstructed consciousness.

5-MeO-DMT is a short-acting psychedelic that is anecdotally reported to induce a radical disruption of the self and a paradoxical quality of aroused, waking awareness that is nevertheless devoid of any specific perceptual contents. Here, we conducted an exploratory observational study of the phenomenological and neuronal effects of this compound. We collected micro-phenomenological interviews, psychometric questionnaires, and electroencephalography (EEG) in naturalistic ceremonial settings where 5-MeO-DMT was ingested.

Cigarette smoking is associated with levels of the serotonin transporter in the brain: a [11C]DASB PET Study.

Background: Preclinical work suggests that chronic nicotine/tobacco use is associated with reductions in serotonin within the hippocampus, yet no research has yet shown an association of smoking behaviors and alterations in brain serotonin in humans in vivo.

Methods: We therefore analyzed existing [11C]DASB PET data from the Cimbi Database to compare the availability of the serotonin transporter (SERT) in the hippocampus, midbrain (including the raphe), and neocortex of 60 healthy non-smokers, 15 ex-smokers, and 11 current smokers who also provided blood samples for determination of plasma tryptophan load. Because SERT availability is considered to be negatively associated with extracellular serotonin levels, we hypothesized that current smokers would exhibit greater SERT availability than ex-smokers and non-smokers.

Neuroplasticity and psychedelics: A comprehensive examination of classic and non-classic compounds in pre and clinical models.

Neuroplasticity, the ability of the nervous system to adapt throughout an organism's lifespan, offers potential as both a biomarker and treatment target for neuropsychiatric conditions. Psychedelics, a burgeoning category of drugs, are increasingly prominent in psychiatric research, prompting inquiries into their mechanisms of action. Distinguishing themselves from traditional medications, psychedelics demonstrate rapid and enduring therapeutic effects after a single or few administrations, believed to stem from their neuroplasticity-enhancing properties.

Correction: Study Protocol for 'PsilOCD: A Pharmacological Challenge Study Evaluating the Effects of the 5-HT2A Agonist Psilocybin on the Neurocognitive and Clinical Correlates of Compulsivity'.

[This corrects the article DOI: 10.7759/cureus.78171.

Study Protocol for 'PsilOCD: A Pharmacological Challenge Study Evaluating the Effects of the 5-HT2A Agonist Psilocybin on the Neurocognitive and Clinical Correlates of Compulsivity'.

Background: Obsessive-compulsive disorder (OCD) is a complex condition marked by persistent distressing thoughts and repetitive behaviours. Despite its prevalence, the mechanisms behind OCD remain elusive, and current treatments are limited. This protocol outlines an investigative study for individuals with OCD, exploring the potential of psilocybin to improve key components of cognition implicated in the disorder.

From relaxed beliefs under psychedelics (REBUS) to revised beliefs after psychedelics (REBAS).

The Relaxed Beliefs Under pSychedelics (REBUS) model proposes that serotonergic psychedelics decrease the precision weighting of neurobiologically-encoded beliefs. We conducted a preliminary examination of two psychological assumptions of REBUS: (a) psychedelics foster acute relaxation and post-acute revision of confidence in mental-health-relevant beliefs; which (b) facilitate positive therapeutic outcomes and are associated with the entropy of EEG signals. Healthy individuals (N = 11) were administered 1 mg and 25 mg psilocybin 4-weeks apart.

Effect of psilocybin versus escitalopram on depression symptom severity in patients with moderate-to-severe major depressive disorder: observational 6-month follow-up of a phase 2, double-blind, randomised, controlled trial.

Background: Psilocybin therapy (PT) produces rapid and persistent antidepressant effects in major depressive disorder (MDD). However, the long-term effects of PT have never been compared with gold-standard treatments for MDD such as pharmacotherapy or psychotherapy alone or in combination.

Methods: This is a 6-month follow-up study of a phase 2, double-blind, randomised, controlled trial involving patients with moderate-to-severe MDD.

Neuroimaging and the Investigation of Drug-Drug Interactions Involving Psychedelics.

Psychedelic therapies are an emerging class of treatments in psychiatry with great potential, however relatively little is known about their interactions with other commonly used psychiatric medications. As psychedelic therapies become more widespread and move closer to the clinic, they likely will need to be integrated into existing treatment models which may include one or more traditional pharmacological therapies, meaning an awareness of potential drug-drug interactions will become vital. This commentary outlines some of the issues surrounding the study of drug-drug interactions of this type, provides a summary of some of the relevant key results to date, and charts a way forward which relies crucially on multimodal neuroimaging investigations.

Impact of psilocybin on cognitive function: A systematic review.

Psilocybin is a classic psychedelic with demonstrated preliminary clinical efficacy in a range of psychiatric disorders. Evaluating the impact of psilocybin on cognitive function is essential to unravel its potential benefits and risks. In this systematic review, we assessed psilocybin's effect on cognitive function through a comprehensive search of electronic databases from inception to January 2024, identifying 20 articles involving 2,959 participants.