Skip to content

Chadi G. Abdallah

14 papers in the library · 1,522 citations · publishing 2014-2026

Papers

Sort Most recent Most cited

Combining DNA methylation features and clinical characteristics predicts ketamine treatment response for PTSD.

iScience January 16, 2026 Amir Valizadeh, John D Roache, Xinyu Zhang et al. 2 citations

Post-traumatic stress disorder (PTSD) exhibits extensive clinical and biological variability, making treatment challenging. The Consortium to Alleviate PTSD (CAP)-ketamine trial, the largest randomized study of ketamine for PTSD, found no overall benefit of ketamine over placebo, underscoring the necessity to identify responsive subgroups. Using pre-treatment blood DNA methylation profiles and...

Challenges and rewards of in vivo synaptic density imaging, and its application to the study of depression.

Neuropsychopharmacology : official publication of the American College of Neuropsychopharmacology November 1, 2024 Ruth H Asch, Chadi G. Abdallah, Richard E Carson et al. 11 citations

The development of novel radiotracers for Positron Emission Tomography (PET) imaging agents targeting the synaptic vesicle glycoprotein 2 A (SV2A), an integral glycoprotein present in the membrane of all synaptic vesicles throughout the central nervous system, provides a method for the in vivo quantification of synaptic density. This is of particular interest in neuropsychiatric disorders given...

Biological embedding of early trauma: the role of higher prefrontal synaptic strength

European Journal of Psychotraumatology August 29, 2023 Lihong Jiang, Amanda J. F. Tamman, Christopher L. Averill et al. 8 citations

Background: Early trauma predicts poor psychological and physical health. Glutamatergic synaptic processes offer one avenue for understanding this relationship, given glutamate's abundance and involvement in reward and stress sensitivity, emotion, and learning. Trauma-induced glutamatergic excitotoxicity may alter neuroplasticity and approach/avoidance tendencies, increasing risk for...

The potential of ketamine for posttraumatic stress disorder: a review of clinical evidence.

Therapeutic Advances in Psychopharmacology 2023 Anya Ragnhildstveit, Jeremy Roscoe, Lisa C. Bass et al. 49 citations

Posttraumatic stress disorder (PTSD) is a devastating condition, for which there are few pharmacological agents, often with a delayed onset of action and poor efficacy. Trauma-focused psychotherapies are further limited by few trained providers and low patient engagement. This frequently results in disease chronicity as well as psychiatric and medical comorbidity, with considerable negative...

International pooled patient-level meta-analysis of ketamine infusion for depression: In search of clinical moderators

Molecular Psychiatry September 7, 2022 Rebecca B Price, Nicholas Kissel, Andrew Baumeister et al. 80 citations

Abstract Depression is disabling and highly prevalent. Intravenous (IV) ketamine displays rapid-onset antidepressant properties, but little is known regarding which patients are most likely to benefit, limiting personalized prescriptions. We identified randomized controlled trials of IV ketamine that recruited individuals with a relevant psychiatric diagnosis (e.g., unipolar or bipolar...

Investigational drugs for assisting psychotherapy for posttraumatic stress disorder (PTSD): emerging approaches and shifting paradigms in the era of psychedelic medicine

Expert Opinion on Investigational Drugs February 1, 2022 Lynnette A. Averill, Chadi G. Abdallah

The unfortunate reality of the mental health crisis plaguing much of the world, in tandem with and exacerbated by the COVID-19 pandemic [1–3], highlights the limited effective pharmacologic treatments in our toolbox for posttraumatic stress disorder (PTSD). There are only two FDA-approved medications indicated for PTSD, both selective serotonin reuptake inhibitors (SSRIs). Though these...

mTORC1 inhibitor effects on rapid ketamine-induced reductions in suicidal ideation in patients with treatment-resistant depression.

Journal of Affective Disorders 2022 L. Averill, C. Averill, R. Gueorguieva et al.

Suicide is a public health crisis with limited treatment options. Ketamine has demonstrated rapid and robust improvements in suicidal ideation (SI). The parent study for the secondary pilot analyses presented here was a double-blind, cross-over trial that found pretreatment with the mechanistic target of rapamycin complex 1 (mTORC1) prolonged the antidepressant effects of ketamine. Here we...

A Robust and Reproducible Connectome Fingerprint of Ketamine is Highly Associated with the Connectomic Signature of Antidepressants

medRxiv Preprint Server April 10, 2020 Chadi G. Abdallah, Kyung-Heup Ahn, Lynnette A. Averill et al. 1 citation preprint

Over the past decade, various N-Methyl-D-Aspartate modulators have failed in clinical trials, underscoring the challenges of developing novel rapid-acting antidepressants based solely on the receptor or regional targets of ketamine. Thus, identifying the effect of ketamine on the brain circuitry and networks is becoming increasingly critical. In this longitudinal functional magnetic resonance...

Modulation of the antidepressant effects of ketamine by the mTORC1 inhibitor rapamycin

Neuropsychopharmacology February 24, 2020 Chadi G. Abdallah, Lynnette A. Averill, Ralitza Gueorguieva et al. 181 citations

Twenty-four hours after administration, ketamine exerts rapid and robust antidepressant effects that are thought to be mediated by activation of the mechanistic target of rapamycin complex 1 (mTORC1). To test this hypothesis, depressed patients were pretreated with rapamycin, an mTORC1 inhibitor, prior to receiving ketamine. Twenty patients suffering a major depressive episode were randomized...

Neurobiological Mechanisms of Ketamine: Depression, Suicide, Trauma, and Chronic Stress Pathologies

Psychiatric Annals February 1, 2020 Lynnette A. Averill, Christopher L. Averill, Chadi G. Abdallah 6 citations

The serendipitous discovery of ketamine's robust antidepressant effects has served as a major catalyst to usher in new era of drug development and a paradigm shift in our understanding of the neurobiology of chronic stress pathology (CSP). This review provides a selective synthesis of (1) the historical foundations of N-methyl-D-aspartate receptor modulators and the path to discovering...

Ketamine: a paradigm shift for depression research and treatment

Neuron March 1, 2019 John H. Krystal, Chadi G. Abdallah, Gerard Sanacora et al. 443 citations

Ketamine is the first exemplar of a rapid-acting antidepressant with efficacy for treatment-resistant symptoms of mood disorders. Its discovery emerged from a reconceptualization of the biology of depression. Neurobiological insights into ketamine efficacy shed new light on the mechanisms underlying antidepressant efficacy. The rapid, profound, and sustainable antidepressant effects of ketamine...

KETAMINE'S MECHANISM OF ACTION: A PATH TO RAPID‐ACTING ANTIDEPRESSANTS

Depression and Anxiety April 6, 2016 Chadi G. Abdallah, Thomas G. Adams, Benjamin Kelmendi et al. 204 citations

Major depressive disorder (MDD) is a common and debilitating psychiatric disorder. Traditional antidepressants are of limited efficacy and take weeks to months to yield full therapeutic effects. Thus, there is a clear need for effective rapid-acting antidepressant medications. The N-methyl-d-aspartate receptor (NMDA-R) antagonist, ketamine, has received a great deal of attention over the last...

Ketamine as a promising prototype for a new generation of rapid‐acting antidepressants

Annals of the New York Academy of Sciences February 27, 2015 Chadi G. Abdallah, Lynnette A. Averill, John H. Krystal 117 citations

The discovery of ketamine's rapid and robust antidepressant effects opened a window into a new generation of antidepressants. Multiple controlled trials and open-label studies have demonstrated these effects across a variety of patient populations known to often achieve little to no response from traditional antidepressants. Ketamine has been generally well tolerated across patient groups, with...

Ketamine and Rapid-Acting Antidepressants: A Window into a New Neurobiology for Mood Disorder Therapeutics

Annual Review of Medicine October 23, 2014 Chadi G. Abdallah, Gerard Sanacora, Ronald S. Duman et al. 420 citations

Ketamine is the prototype for a new generation of glutamate-based antidepressants that rapidly alleviate depression within hours of treatment. Over the past decade, there has been replicated evidence demonstrating the rapid and potent antidepressant effects of ketamine in treatment-resistant depression. Moreover, preclinical and biomarker studies have begun to elucidate the mechanism underlying...