Classifying Obsessive-Compulsive Disorder from Resting-State EEG using Convolutional Neural Networks: A Pilot Study.

Objective: Classifying obsessive-compulsive disorder (OCD) using brain data remains challenging. Resting-state electroencephalography (EEG) offers an affordable and noninvasive approach, but traditional machine learning methods have limited its predictive capability. We explored whether convolutional neural networks (CNNs) applied to minimally processed EEG time-frequency representations could offer a solution, effectively distinguishing individuals with OCD from healthy controls.

Network-based Molecular Constraints on Synaptic Density Alterations in Schizophrenia.

Converging neuroimaging, genetic, and post-mortem evidence show a fundamental role of synaptic deficits in schizophrenia pathogenesis. However, the underlying molecular and cellular mechanisms that drive the onset and progression of synaptic pathology remain to be established. Here, we used synaptic density positron emission tomography (PET) imaging using the [C]UCB-J radiotracer to reveal a prominent widespread pattern ( < 0.

The regional pattern of age-related synaptic loss in the human brain differs from gray matter volume loss: in vivo PET measurement with [C]UCB-J.

Purpose: Aging is a major societal concern due to age-related functional losses. Synapses are crucial components of neural circuits, and synaptic density could be a sensitive biomarker to evaluate brain function. [C]UCB-J is a positron emission tomography (PET) ligand targeting synaptic vesicle glycoprotein 2A (SV2A), which can be used to evaluate brain synaptic density in vivo.

Sub-acute effects of psilocybin on EEG correlates of neural plasticity in major depression: Relationship to symptoms.

Background: Evidence suggests that serotonergic psychedelics (e.g. psilocybin), have rapid-acting and long-lasting antidepressant effects after a single dose.

Preliminary study of the interactive effects of THC and ethanol on self-reported ability and simulated driving, subjective effects, and cardiovascular responses.

Rationale: Drug- and alcohol-related motor vehicle accidents are a leading cause of morbidity and mortality worldwide. Compared to alcohol, less is known about the effects of cannabis on driving and even less about their combined effects.

Objective: To characterize the combined and separate effects of ethanol and tetrahydrocannabinol (THC) on perceived ability to drive, subjective effects, and simulated driving.

Psilocybin-assisted therapy for major depressive disorder: An exploratory placebo-controlled, fixed-order trial.

Background: Several early phase studies have demonstrated that psilocybin-assisted therapy has rapid-acting and persisting antidepressant effects from just one or two doses. However, methodological limitations (e.g.

The Relationship Between Cannabinoids and Neural Oscillations: How Cannabis Disrupts Sensation, Perception, and Cognition.

Disruptions in neural oscillations are believed to be one critical mechanism by which cannabinoids, such as delta-9-tetrahyrdrocannabinol (THC; the primary psychoactive constituent of cannabis), perturbs brain function. Here we briefly review the role of synchronized neural activity, particularly in the gamma (30-80 Hz) and theta (4-7 Hz) frequency range, in sensation, perception, and cognition. This is followed by a review of clinical studies utilizing electroencephalography (EEG) which have demonstrated that both chronic and acute cannabinoid exposure disrupts neural oscillations in humans.

Age, gender and body-mass-index relationships with in vivo CB receptor availability in healthy humans measured with [C]OMAR PET.

Brain cannabinoid 1 receptors (CB1Rs) contribute importantly to the regulation of autonomic tone, appetite, mood and cognition. Inconsistent results have been reported from positron emission tomography (PET) studies using different radioligands to examine relationships between age, gender and body mass index (BMI) and CB1R availability in healthy individuals. In this study, we examined these variables in 58 healthy individuals (age range: 18-55 years; 44 male; BMI=27.

Sex differences in the acute effects of intravenous (IV) delta-9 tetrahydrocannabinol (THC).

Background: Cannabis is the most common illicit drug used in the USA and its use has been rising over the past decade, while the historical gap in rates of use between men and women has been decreasing. Sex differences in the effects of cannabinoids have been reported in animal models, but human studies are sparse and inconsistent. We investigated the sex differences in the acute subjective, psychotomimetic, cognitive, and physiological effects of intravenous (IV) delta-9 tetrahydrocannabinol (THC), the main psychoactive constituent of cannabis.

Delta-9-Tetrahydrocannabinol, Cannabidiol, and Acute Psychotomimetic States: A Balancing Act of the Principal Phyto-Cannabinoids on Human Brain and Behavior.

THC and CBD are the principal phyto-cannabinoids in the cannabis plant. The differential and possibly antagonistic effects of these compounds on specific brain and behavioral responses, and the mechanisms underlying their effects have generated extensive interest in pre-clinical and clinical neuroscience investigations. In this double-blind randomized placebo-controlled counterbalanced Human Laboratory Study, we examined the effects of three different dose ratios of CBD:THC (1:1, 2:1, and 3:1) on "neural noise," an electrophysiological biomarker of psychosis known to be sensitive to cannabinoids as well as subjective and psychotomimetic effects.

Lower prefrontal cortical synaptic vesicle binding in cocaine use disorder: An exploratory C-UCB-J positron emission tomography study in humans.

Preclinical studies have revealed robust and long-lasting alterations in dendritic spines in the brain following cocaine exposure. Such alterations are hypothesized to underlie enduring maladaptive behaviours observed in cocaine use disorder (CUD). The current study explored whether synaptic density is altered in CUD.

Electroencephalographic Correlates and Predictors of Treatment Outcome in OCD: A Brief Narrative Review.

Electroencephalography (EEG) measures the brain's electrical activity with high temporal resolution. In comparison to neuroimaging modalities such as MRI or PET, EEG is relatively cheap, non-invasive, portable, and simple to administer, making it an attractive tool for clinical deployment. Despite this, studies utilizing EEG to investigate obsessive-compulsive disorder (OCD) are relatively sparse.

Assessment of transient dopamine responses to smoked cannabis.

Background: Dopaminergic mechanisms that may underlie cannabis' reinforcing effects are not well elucidated in humans. This positron emission tomography (PET) imaging study used the dopamine D receptor antagonist [C]raclopride and kinetic modelling testing for transient changes in radiotracer uptake to assess the striatal dopamine response to smoked cannabis in a preliminary sample.

Methods: PET emission data were acquired from regular cannabis users (n = 14; 7 M/7 F; 19-32 years old) over 90 min immediately after [C]raclopride administration (584 ± 95 MBq) as bolus followed by constant infusion (K = 105 min).

Decision Making and Impulsivity in Young Adult Cannabis Users.

Chronic cannabis users show impairments on laboratory measures of decision making which reflect risk factors for initiation and continued use of cannabis. However, the differential sensitivity of these tasks to cannabis use has not been established. Moreover, studies to date have often lacked assessment of psychiatric histories and use of other illicit substances, both of which may influence decision making outcomes.

In vivo evidence of lower synaptic vesicle density in schizophrenia.

Decreased synaptic spine density has been the most consistently reported postmortem finding in schizophrenia (SCZ). A recently developed in vivo measure of synaptic vesicle density estimated using the novel positron emission tomography (PET) ligand [C]UCB-J is a proxy measure of synaptic density. In this study we determined whether [C]UCB-J binding, an in vivo measure of synaptic vesicle density, is altered in SCZ.

Analysis of circulating exosomes reveals a peripheral signature of astrocytic pathology in schizophrenia.

Objectives: Extracellular vesicles, including exosomes, cross the blood brain barrier with their contents intact and can be assayed peripherally. Circulating exosomes have been studied in other neurodegenerative disorders, but there is scarce data in schizophrenia. This study aimed to examine neuropathology-relevant protein biomarkers in circulating plasma-derived exosomes from patients with schizophrenia and age- and sex-matched healthy controls.

Psychosis-Relevant Effects of Intravenous Delta-9-Tetrahydrocannabinol: A Mega Analysis of Individual Participant-Data from Human Laboratory Studies.

Introduction: There is increasing interest in the relationship between cannabinoids and psychosis. While individual human laboratory studies have been critical in demonstrating that cannabinoids (e.g.

Efficacy and safety of a fatty acid amide hydrolase inhibitor (PF-04457845) in the treatment of cannabis withdrawal and dependence in men: a double-blind, placebo-controlled, parallel group, phase 2a single-site randomised controlled trial.

Background: Cannabis is one of the most widely used drugs worldwide. Cannabis use disorder is characterised by recurrent use of cannabis that causes significant clinical and functional impairment. There are no approved pharmacological treatments for cannabis use disorder.

The dose-dependent psychomotor effects of intravenous delta-9-tetrahydrocannabinol (Δ-THC) in humans.

Background: Binding studies have demonstrated that levels of the cannabinoid receptor type-1 are highest in the basal ganglia and cerebellum, two areas critical for motor control. However, no studies have systematically examined the dose-related effects of intravenous delta-9-tetrahydrocannabinol, the primary cannabinoid receptor type-1 partial agonist in cannabis, on broad domains of psychomotor function in humans.

Aims: Therefore, three domains of psychomotor function were assessed in former cannabis users (cannabis abstinent for a minimum of three months; n=23) in a three test-day, within-subject, double-blind, randomized, cross-over, and counterbalanced study during which they received intravenous delta-9-tetrahydrocannabinol (placebo, 0.

Cannabinoid receptor-mediated disruption of sensory gating and neural oscillations: A translational study in rats and humans.

Cannabis use has been associated with altered sensory gating and neural oscillations. However, it is unclear which constituent in cannabis is responsible for these effects, or whether these are cannabinoid receptor 1 (CB1R) mediated. Therefore, the present study in humans and rats examined whether cannabinoid administration would disrupt sensory gating and evoked oscillations utilizing electroencephalography (EEG) and local field potentials (LFPs), respectively.

Cannabinoid-glutamate interactions and neural oscillations: implications for psychosis.

Preclinical and clinical data suggest that the cannabinoid and glutamatergic systems are implicated in the pathophysiology of schizophrenia (SZ), the prototypical psychotic disorder. This has led to distinct "cannabis" and "ketamine" models of SZ, respectively. However, these two models need not be mutually exclusive.

Tetrahydrocannabinol (THC) impairs encoding but not retrieval of verbal information.

Introduction: Cannabis and agonists of the brain cannabinoid receptor (CBR) produce acute memory impairments in humans. However, the extent to which cannabinoids impair the component processes of encoding and retrieval has not been established in humans. The objective of this analysis was to determine whether the administration of Δ-Tetrahydrocannabinol (THC), the principal psychoactive constituent of cannabis, impairs encoding and/or retrieval of verbal information.

Cannabinoids and Psychosis.

There is growing interest in the relationship between cannabis and psychosis. The link between cannabis use and psychosis comprises three distinct relationships: acute psychosis associated with cannabis intoxication, acute psychosis that lasts beyond the period of acute intoxication, and persistent psychosis not time-locked to exposure. Experimental studies reveal that cannabis, tetrahydrocannabinol (THC) and synthetic cannabinoids reliably produce transient positive, negative, and cognitive symptoms in healthy volunteers.