American Journal of Psychiatry
June 3, 2026
Deepak C D'Souza, Jose A Cortes-Briones, Justin Raj et al.
OBJECTIVE Cannabis use is a known risk factor for psychosis, but it remains unclear whether cannabis-associated psychosis (CAP) differs meaningfully from non-cannabis-associated psychosis (NCAP) in clinical presentation, biology, or illness course. The objective of this study was to characterize the presentation and course of first-episode psychosis with and without cannabis exposure. METHODS...
JAMA Internal Medicine
May 1, 2026
Devan Kansagara, Garth E Terry, Chelsea K Ayers et al.
Cannabis use is common among those with mental health conditions, and many people report using cannabis to manage mental health symptoms. It is important for clinicians to understand the lack of clear benefits of cannabis for mental health conditions and the potential for substantial adverse effects. Overall, the potential benefits of cannabis for mental health conditions remain poorly studied....
Headache: The Journal of Head and Face Pain
December 29, 2025
Emmanuelle A. D. Schindler, Christopher Gottschalk, Brian Pittman et al.
1 citation
Abstract Objective The goals of this study were to examine the therapeutic effects and safety of psilocybin given as a pulsed regimen for the prevention of migraine and to consider the blinding integrity of an active control agent. Background The administration of a single low dose of psilocybin was observed to have lasting therapeutic effects in one small pilot trial in migraine, although the...
bioRxiv : the preprint server for biology
August 22, 2025
Jose A Cortes-Briones, Juan Urrutia-Gandolfo, Pablo A Estevez et al.
preprint
The balance between excitatory and inhibitory (E/I) activity is critical for brain function, and its disruption is implicated in neuropsychiatric disorders. Electrophysiological signals can be decomposed into periodic (oscillatory) and aperiodic components. In the power spectrum, the periodic component appears as narrowband peaks, while the aperiodic component underlies its characteristic 1 / f...
Journal of the Neurological Sciences
May 15, 2024
Emmanuelle A. D. Schindler, R Andrew Sewell, Christopher Gottschalk et al.
37 citations
In a recent randomized, double-blind, placebo-controlled study, we observed a nonsignificant reduction of attack frequency in cluster headache after pulse administration of psilocybin (10 mg/70 kg, 3 doses, 5 days apart each). We carried out a blinded extension phase to consider the safety and efficacy of repeating the pulse regimen. Eligible participants returned to receive a psilocybin pulse...
Neuropsychopharmacology
July 2022
Chadi G. Abdallah, John D Roache, Ralitza Gueorguieva et al.
This study tested the efficacy of repeated intravenous ketamine doses to reduce symptoms of posttraumatic stress disorder (PTSD). Veterans and service members with PTSD (n = 158) who failed previous antidepressant treatment were randomized to 8 infusions administered twice weekly of intravenous placebo (n = 54), low dose (0.2 mg/kg; n = 53) or standard dose (0.5 mg/kg; n = 51) ketamine....
Neurotherapeutics
2021
Emmanuelle A. D. Schindler, R Andrew Sewell, Christopher Gottschalk et al.
138 citations
While anecdotal evidence suggests that select 5-hydroxytryptamine 2A (5-HT2A) receptor ligands, including psilocybin, may have long-lasting therapeutic effects after limited dosing in headache disorders, controlled investigations are lacking. In an exploratory double-blind, placebo-controlled, cross-over study, adults with migraine received oral placebo and psilocybin (0.143 mg/kg) in 2 test...
Psychopharmacology
September 1, 2019
Swapnil Gupta, Joao P De Aquino, Deepak C D'Souza et al.
Δ-9-Tetrahydrocannabinol (Δ-9-THC) produces psychotomimetic effects in humans. However, the role of dopamine signaling in producing such effects is unclear. We hypothesized that dopaminergic antagonism would reduce the psychotomimetic effect of Δ-9-THC. The objective of this study was to evaluate whether pre-treatment with haloperidol would alter the psychotomimetic and perceptual-altering...
Journal of Psychopharmacology
December 2018
Douglas L Boggs, Jose A Cortes-Briones, Toral Surti et al.
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...
Neuropharmacology
June 2018
Patrick D. Skosnik, Mihály Hajós, Jose A Cortes-Briones et al.
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...
Frontiers in Pharmacology
March 1, 2018
Emmanuelle A. D. Schindler, Ryan M Wallace, Jordan Sloshower et al.
Recent reports on the effects of psychedelic-assisted therapies for mood disorders and addiction, as well as the effects of psychedelics in the treatment of cluster headache, have demonstrated promising therapeutic results. In addition, the beneficial effects appear to persist well after limited exposure to the drugs, making them particularly appealing as treatments for chronic neuropsychiatric...
Neuropsychopharmacology
December 2014
Patrick D. Skosnik, Giri P Krishnan, Deepak C D'Souza et al.
Previous work in animals and humans has shown that exogenous cannabinoids disrupt time-locked, evoked gamma oscillations (30-80 Hz). However, no studies to date have examined the effect of cannabis on non-time-locked, induced gamma oscillations during more complex Gestalt perception. The current study therefore utilized electroencephalography (EEG) to examine gamma oscillations during coherent...
The International Journal of Neuropsychopharmacology
October 2012
Mohini Ranganathan, Michelle Carbuto, Gabriel Braley et al.
Although a wealth of preclinical evidence indicates an interplay between the μ-opioid (MOR) and cannabinoid 1 receptor (CB1R) systems, the precise nature of the cross modulation in humans is unclear. The objective of this study was to evaluate the effects of pretreatment with the MOR antagonist, naltrexone, on the subjective, behavioural and cognitive effects of the CB1R agonist,...
Neuropsychopharmacology
September 2012
Patrick D. Skosnik, Deepak C D'Souza, Adam B. Steinmetz et al.
Animal and cellular work has shown that central cannabinoid-1 receptors modulate neural oscillations in the gamma range (40 Hz), which may be important for normal perceptual and cognitive processes. In order to assess the effect of cannabinoids on broadband-frequency neural oscillations in humans, the current study examined the effect of chronic cannabis use on auditory steady-state responses...
Biological Psychiatry
June 1, 2012
Handan Gunduz-Bruce, Robert M G Reinhart, Brian J Roach et al.
Auditory mismatch negativity (MMN) and P300 event-related potentials (ERPs) are reduced in schizophrenia patients and healthy volunteers administered the N-methyl-D-aspartate glutamate receptor antagonist, ketamine. In rodents, N-acetylcysteine (NAC), a stimulator of the cystine-glutamate exchanger, attenuates the cognitive and behavioral effects of N-methyl-D-aspartate receptor antagonists. On...
Pharmacopsychiatry
July 1, 1998
Walid Abi‐saab, Deepak C D'Souza, Bita Moghaddam et al.
Drug models have been extensively used to study the pathophysiology of schizophrenia. While they provide good insight into the neurobiology of this disorder, they have several shortcomings, which if known, help in the interpretation of results. In this paper we will discuss these shortcomings in general, and in relation to the N-methyl D-aspartate antagonist model for schizophrenia. This model...