Journal of Neuroscience Research
2026
Stephanie N Njau, Artemis Zavaliangos-Petropulu, Shantanu Joshi et al.
Ketamine has emerged as a highly effective intervention for treatment-resistant depression (TRD). Though it acts as a non-competitive antagonist of excitatory N-methyl-D-aspartate receptors (NMDAR), widely expressed in the brain, including on inhibitory γ-aminobutyric acid (GABA)-ergic cells, the mechanisms of its antidepressant action are less clear. To investigate the links between glutamate...
medRxiv
July 29, 2025
Artemis Zavaliangos-Petropulu, Ginny Ghang, Toni Boltz et al.
preprint
Background: Treatment-resistant depression (TRD) affects 30-50% of patients with major depressive disorder (MDD). Electroconvulsive therapy (ECT) and sub-anesthetic ketamine treatment can relieve TRD, yet their antidepressant mechanisms remain unclear. Peripheral blood gene expression offers a non-invasive proxy to examine potential treatment-response biomarkers. Methods: We conducted a...
Imaging Neuroscience
2025
Brandon Taraku, Jason S Nomi, Artemis Zavaliangos-Petropulu et al.
Ketamine produces fast-acting antidepressant effects in treatment-resistant depression (TRD). Prior studies have shown altered functional dynamics between brain networks in major depression. We thus sought to determine whether functional brain network dynamics are modulated by ketamine therapy in TRD. Participants with TRD (n = 58, mean age = 40.7 years, female = 48.3%) completed resting-state...
Brain and Behavior
June 1, 2024
Brandon Taraku, Joana R Loureiro, Ashish K Sahib et al.
11 citations
Major depressive disorder (MDD) is associated with dysfunctional reward processing, which involves functional circuitry of the habenula (Hb) and nucleus accumbens (NAc). Since ketamine elicits rapid antidepressant and antianhedonic effects in MDD, this study sought to investigate how serial ketamine infusion (SKI) treatment modulates static and dynamic functional connectivity (FC) in Hb and NAc...
medRxiv Preprint Server
December 1, 2023
Brandon Taraku, Joana R Loureiro, Ashish K Sahib et al.
1 citation
preprint
Dysfunctional reward processing in major depressive disorder (MDD) involves functional circuitry of the habenula (Hb) and nucleus accumbens (NAc). Ketamine elicits rapid antidepressant and alleviates anhedonia in MDD. To clarify how ketamine perturbs reward circuitry in MDD, we examined how serial ketamine infusions (SKI) modulate static and dynamic functional connectivity (FC) in Hb and NAc...
Frontiers in Psychiatry
October 9, 2023
Artemis Zavaliangos-Petropulu, Shawn M. Mcclintock, S. Joshi et al.
6 citations
Introduction Subanesthetic ketamine is a rapidly acting antidepressant that has also been found to improve neurocognitive performance in adult patients with treatment resistant depression (TRD). Provisional evidence suggests that ketamine may induce change in hippocampal volume and that larger pre-treatment volumes might be related to positive clinical outcomes. Here, we examine the effects of...
Journal of Affective Disorders
April 1, 2023
Artemis Zavaliangos-Petropulu, Shawn M. Mcclintock, Jacqueline Khalil et al.
16 citations
INTRODUCTION Ketamine treatment prompts a rapid antidepressant response in treatment-resistant depression (TRD). We performed an exploratory investigation of how ketamine treatment in TRD affects different cognitive domains and relates to antidepressant response. METHODS Patients with TRD (N = 66; 30 M/35F; age = 39.5 ± 11.1 years) received four ketamine infusions (0.5 mg/kg). Neurocognitive...
Human Brain Mapping
January 30, 2023
Brandon Taraku, Roger P Woods, Michael Boucher et al.
23 citations
Ketamine produces fast‐acting antidepressant effects in treatment resistant depression (TRD). Though prior studies report ketamine‐related changes in brain activity in TRD, understanding of ketamine's effect on white matter (WM) microstructure remains limited. We thus sought to examine WM neuroplasticity and associated clinical improvements following serial ketamine infusion (SKI) in TRD. TRD...
Biological Psychiatry: Cognitive Neuroscience and Neuroimaging
November 25, 2022
Artemis Zavaliangos-Petropulu, Noor B. Al-Sharif, Brandon Taraku et al.
27 citations
Major depressive disorder is a highly prevalent psychiatric disorder. Despite an extensive range of treatment options, about a third of patients still struggle to respond to available therapies. In the last 20 years, ketamine has gained considerable attention in the psychiatric field as a promising treatment of depression, particularly in patients who are treatment resistant or at high risk for...
Psychological Medicine
October 1, 2022
Ashish K Sahib, Joana R Loureiro, Megha M Vasavada et al.
36 citations
Subanesthetic ketamine infusion therapy can produce fast-acting antidepressant effects in patients with major depression. How single and repeated ketamine treatment modulates the whole-brain functional connectome to affect clinical outcomes remains uncharacterized. Data-driven whole brain functional connectivity (FC) analysis was used to identify the functional connections modified by ketamine...
Psychological Medicine
September 1, 2022
Benjamin Wade, Joana R Loureiro, Ashish K Sahib et al.
18 citations
Ketamine is a rapidly-acting antidepressant treatment with robust response rates. Previous studies have reported that serial ketamine therapy modulates resting state functional connectivity in several large-scale networks, though it remains unknown whether variations in brain structure, function, and connectivity impact subsequent treatment success. We used a data-driven approach to determine...
Translational Psychiatry
March 21, 2021
Jennifer L. Kruse, Megha M Vasavada, Richard Olmstead et al.
47 citations
Abstract Inflammation plays a role in depression pathophysiology and treatment response, with effects varying by sex and therapeutic modality. Lower levels of interleukin(IL)-8 predict depression response to antidepressant medication and to electroconvulsive therapy (ECT), although ECT effects are specific to females. Whether IL-8 predicts depression response to ketamine and in a sex-specific...
Translational Psychiatry
July 30, 2020
Ashish K Sahib, Joana Ra Loureiro, Megha M Vasavada et al.
37 citations
Subanesthetic ketamine is found to induce fast-acting and pronounced antidepressant effects, even in treatment resistant depression (TRD). However, it remains unclear how ketamine modulates neural function at the brain systems-level to regulate emotion and behavior. Here, we examined treatment-related changes in the inhibitory control network after single and repeated ketamine therapy in TRD....
Human Brain Mapping
May 1, 2020
Joana R Loureiro, Amber M Leaver, Megha M Vasavada et al.
65 citations
Electroconvulsive therapy (ECT) and ketamine treatment both induce rapidly acting antidepressant effects in patients with major depressive disorder unresponsive to standard treatments, yet their specific impact on emotion processing is unknown. Here, we examined the neural underpinnings of emotion processing within and across patients (N = 44) receiving either ECT (N = 17, mean age: 36.8, 11.0...
Journal of Affective Disorders
January 15, 2016
Megha M Vasavada, Amber M Leaver, Randall Espinoza et al.
58 citations
Ketamine elicits an acute antidepressant effect in patients with major depressive disorder (MDD). Here, we used diffusion imaging to explore whether regional differences in white matter microstructure prior to treatment may predict clinical response 24h following ketamine infusion in 10 MDD patients. FSL's Tract-Based Spatial Statistics (TBSS) established voxel-level differences in fractional...
Frontiers in Aging Neuroscience
2016
Hongyu Yang, Amber M Leaver, Prabha Siddarth et al.
Behavioral interventions are becoming increasingly popular approaches to ameliorate age-related cognitive decline, but their underlying neurobiological mechanisms and clinical efficiency have not been fully elucidated. The present study explored brain plasticity associated with two behavioral interventions, memory enhancement training (MET) and a mind-body practice (yogic meditation), in...
Human Brain Mapping
December 2013
Eileen Luders, Paul M Thompson, Florian Kurth et al.
Studies linking meditation and brain structure are still relatively sparse, but the hippocampus is consistently implicated as one of the structures altered in meditation practitioners. To explore hippocampal features in the framework of meditation, we analyzed high-resolution structural magnetic resonance imaging data from 30 long-term meditators and 30 controls, closely matched for sex, age,...
Frontiers in Psychology
2013
Eileen Luders, Florian Kurth, Arthur W Toga et al.
89 citations
Scientific studies addressing anatomical variations in meditators' brains have emerged rapidly over the last few years, where significant links are most frequently reported with respect to gray matter (GM). To advance prior work, this study examined GM characteristics in a large sample of 100 subjects (50 meditators, 50 controls), where meditators have been practicing close to 20 years, on...
Frontiers in Human Neuroscience
February 29, 2012
Eileen Luders, Florian Kurth, Emeran A Mayer et al.
Several cortical regions are reported to vary in meditation practitioners. However, prior analyses have focused primarily on examining gray matter or cortical thickness. Thus, additional effects with respect to other cortical features might have remained undetected. Gyrification (the pattern and degree of cortical folding) is an important cerebral characteristic related to the geometry of the...
Neuroimage
February 21, 2012
Eileen Luders, Owen R Phillips, Kristi Clark et al.
Recent findings suggest a close link between long-term meditation practices and the structure of the corpus callosum. Prior analyses, however, have focused on estimating mean fractional anisotropy (FA) within two large pre-defined callosal tracts only. Additional effects might exist in other, non-explored callosal regions and/or with respect to callosal attributes not captured by estimates of...
Neuroimage
June 6, 2011
Eileen Luders, Kristi Clark, Katherine L Narr et al.
Very little is currently known about the cerebral characteristics that underlie the complex processes of meditation as only a limited number of studies have addressed this topic. Research exploring structural connectivity in meditation practitioners is particularly rare. We thus acquired diffusion tensor imaging (DTI) data of high angular and spatial resolution and used atlas-based tract...