Christopher L Averill

Christopher L Averill
Baylor College of Medicine | BCM · Department of Psychiatry & Behavioral Sciences

Bachelor of Science

About

64
Publications
19,169
Reads
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1,516
Citations
Introduction
I am a neuroimaging specialist in the Emerge Research Program at Baylor College of Medicine. My background in MRI/MRS, genetics, biotech device R&D, scale development and latent variable analysis, computer programming, and data science have shaped my interests, which include the neuropathophysiology of chronic stress, applications of neuroimaging and deep learning for precision medicine. Reddit: u/tekgy at r/psykratia. Twitter: @tekgy.
Additional affiliations
August 2021 - present
Baylor College of Medicine
Position
  • Laboratory Manager
Description
  • Clinical Research Lead. Lab manager. Acquire, process, analyze, & report findings of sMRI, fMRI, dMRI, pMRI, MRS, NMR, and EEG data. Develop and refine methods for the same.
February 2015 - present
Yale University
Position
  • Researcher
Description
  • Converted from employment to affiliation only status in August 2020. Acquire, process, analyze, & report findings of sMRI, fMRI, dMRI, pMRI, MRS, NMR, and EEG data. Develop and refine methods for the same. Train and supervise staff in acquisition and processing of data.
January 2007 - August 2008
University of Utah
Position
  • Teaching & Curriculum Assistant
Description
  • Work with Positive Psychology faculty to develop curriculum; TA, 3 semesters (Quality Intimate Relations and Changing Addictive Thinking courses); grading/feedback; etc.
Education
August 2001 - May 2005
Westminster College
Field of study
  • Biology (Genetics)

Publications

Publications (64)
Conference Paper
Post-traumatic stress disorder (PTSD) is an anxiety condition evidenced by wide-ranging emotional and cognitive dysfunction. While prefrontal glutamatergic excitotoxicity is thought to contribute to its presentation, no 1H-MRS studies of PTSD have yet been conducted at 7-Tesla field strength facilitating separation of glutamate from metabolic partn...
Article
Full-text available
Background Trauma and chronic stress are believed to induce and exacerbate psychopathology by disrupting glutamate synaptic strength. However, in vivo in human methods to estimate synaptic strength are limited. In this study, we established a novel putative biomarker of glutamatergic synaptic strength, termed energy-per-cycle (EPC). Then, we used E...
Article
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 a...
Article
Full-text available
Background Exposed-based psychotherapy is a mainstay of treatment for obsessive-compulsive disorder (OCD) and anxious psychopathology. The medial prefrontal cortex (mPFC) and the default mode network (DMN), which is anchored by the mPFC, promote safety learning. Neuromodulation targeting the mPFC might augment therapeutic safety learning and enhanc...
Article
Full-text available
Background Posttraumatic stress disorder (PTSD) is associated with markers of accelerated aging. Estimates of brain age, compared to chronological age, may clarify the effects of PTSD on the brain and may inform treatment approaches targeting the neurobiology of aging in the context of PTSD. Method Adult subjects (N = 2229; 56.2% male) aged 18–69...
Chapter
Full-text available
A vast literature demonstrates that traumatic stress has deleterious effects on the brain; however, the precise mechanisms through which these neural alterations occur is not fully elucidated. Neurocircuitry and neuroplasticity have been identified as critical components in determining an individual's stress tolerance and response In this abridged...
Article
Full-text available
A growing number of studies have examined alterations in white matter organization in people with posttraumatic stress disorder (PTSD) using diffusion MRI (dMRI), but the results have been mixed which may be partially due to relatively small sample sizes among studies. Altered structural connectivity may be both a neurobiological vulnerability for,...
Preprint
Full-text available
Trauma and chronic stress are believed to induce and exacerbate psychopathology by disrupting glutamate synaptic strength. However, in vivo in human methods to estimate synaptic strength are limited. In this study, we established a novel putative biomarker of glutamatergic synaptic strength, termed energy-per-cycle (EPC). Then, we used EPC to inves...
Preprint
Background: Psychotherapy based on fear extinction is a mainstay of treatment for obsessive-compulsive disorder (OCD). The default mode network (DMN) is important to safety signal processing, fear extinction, and exposure-based therapies. The medial prefrontal cortex (mPFC) is an anchor of the DMN. Neuromodulation targeting the mPFC might augment t...
Article
Background Smoking behavior during the first 24 hours of a quit attempt is a significant predictor of longer term abstinence, yet little is known about the neurobiology of early tobacco abstinence. Specifically, the effects of acute tobacco deprivation and reinstatement on brain function—particularly at the level of large-scale network dynamics and...
Article
Full-text available
Background Major depressive disorder (MDD) treatment is characterized by low remission rate and often involves weeks to months of treatment. Identification of pretreatment biomarkers of response may play a critical role in novel drug development, in enhanced prognostic predictions, and perhaps in providing more personalized medicine. Using a networ...
Article
Full-text available
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 th...
Preprint
Full-text available
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 th...
Article
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...
Article
Full-text available
More than six decades have passed since the discovery of monoaminergic antidepressants. Yet, it remains a mystery why these drugs take weeks to months to achieve therapeutic effects, although their monoaminergic actions are present rapidly after treatment. In an attempt to solve this mystery, rather than studying the acute neurochemical effects of...
Article
Background: Posttraumatic stress disorder (PTSD) is a debilitating mental illness that is thought to be associated with brain white matter (WM) alterations. Individual diffusion tensor imaging (DTI) studies to date have reported inconsistent alterations in FA across different brain regions in patients with PTSD. Here, we aimed to investigate FA in...
Preprint
Full-text available
Background PTSD and depression commonly co-occur and have been associated with smaller hippocampal volumes compared to healthy and trauma-exposed controls. However, the hippocampus is heterogeneous, with subregions that may be uniquely affected in individuals with PTSD and depression. Methods We used random effects regressions and a harmonized neu...
Preprint
Full-text available
A growing number of studies have examined alterations in white matter organization in people with posttraumatic stress disorder (PTSD) using diffusion MRI (dMRI), but the results have been mixed, which may be partially due to relatively small sample sizes among studies. Altered structural connectivity may be both a neurobiological vulnerability for...
Article
Full-text available
Background: Better understanding of the neurobiology of posttraumatic stress disorder (PTSD) may be critical to developing novel, effective therapeutics. Here, we conducted a data-driven investigation using a well-established, graph-based topological measure of nodal strength to determine the extent of functional dysconnectivity in a cohort of act...
Article
Full-text available
Background: In soldiers with posttraumatic stress disorder (PTSD), symptom provocation was found to induce increased connectivity within the salience network, as measured by functional magnetic resonance imaging (fMRI) and global brain connectivity with global signal regression (GBCr). However, it is unknown whether these GBCr disturbances would n...
Preprint
Full-text available
BACKGROUND: In soldiers with posttraumatic stress disorder (PTSD), symptom provocation was found to induce increased connectivity within the salience network, as measured by functional magnetic resonance imaging (fMRI) and global brain connectivity with global signal regression (GBCr). However, it is unknown whether these GBCr disturbances would no...
Preprint
Full-text available
BACKGROUND: Better understanding of the neurobiology of posttraumatic stress disorder (PTSD) may be critical to developing novel, effective therapeutics. Here, we conducted a data-driven investigation using a well-established, graph- based topological measure of nodal strength to determine the extent of functional dysconnectivity in a cohort of act...
Article
Full-text available
Background: Identifying the neural correlates of ketamine treatment may facilitate and expedite the development of novel, robust, and safe rapid-acting antidepressants. Prefrontal cortex (PFC) global brain connectivity with global signal regression (GBCr) was recently identified as a putative biomarker of major depressive disorder (MDD). Accumulat...
Article
Full-text available
New approaches to the neurobiology of posttraumatic stress disorder (PTSD) are needed to address the reported crisis in PTSD drug development. These new approaches may require the field to move beyond a narrow fear-based perspective, as fear-based medications have not yet demonstrated compelling efficacy. Antidepressants, particularly recent rapid-...
Article
Full-text available
Here we present functional neuroimaging-based network data (focused on the default mode network) collected from a cohort of US Veterans with history of combat exposure, combined with clinical assessments for PTSD and other psychiatric comorbidities. The data has been processed and analyzed using several network construction methods (signed, thresho...
Article
Purpose of the study: Prior studies showed posttraumatic stress disorder (PTSD)-related alterations in white matter integrity, but most of these studies have used region-based approaches. We address this limitation by investigating the relationship between PTSD severity and fractional anisotropy (FA) using a tract-based approach. Procedures: Str...
Article
Full-text available
The ability of ketamine administration to activate prefrontal glutamate neurotransmission is thought to be a key mechanism contributing to its transient psychotomimetic effects and its delayed and sustained antidepressant effects. Rodent studies employing carbon-13 magnetic resonance spectroscopy (13C MRS) methods have shown ketamine and other N-me...
Poster
Full-text available
Manuscript Now Published at Molecular Neuropsychiatry. CITATION: Averill CL, Averill LA, Wrocklage KM, Scott JC, Akiki TJ, Schweinsburg B, Southwick SM, Krystal JH, Abdallah CG. Altered white matter diffusivity of the cingulum angular bundle in posttraumatic stress disorder. Mol Neuropsychiatry 2018;4:75–82. https://doi.org/10.1159/000490464
Article
Full-text available
Disruption in the default mode network (DMN) has been implicated in numerous neuropsychiatric disorders, including posttraumatic stress disorder (PTSD). However, studies have largely been limited to seed-based methods and involved inconsistent definitions of the DMN. Recent advances in neuroimaging and graph theory now permit the systematic explora...
Article
Full-text available
Purpose of review: This review focuses on the relationship between resilience and the ability to effectively modulate the stress response. Neurobiological and behavioral responses to stress are highly variable. Exposure to a similar stressor can lead to heterogeneous outcomes-manifesting psychopathology in one individual, but having minimal effect...
Poster
Full-text available
The Methodological Question: Can fMRI-derived restricted-network biomarkers serve as robust marker of PTSD symptomatology? Can these network-analyses identify abnormalities that can potentially be targeted using circuit-based therapeutics?
Article
Full-text available
The Opioid Abuse Risk Screener was developed to support well-informed decision-making in opioid analgesic prescribing by extending the breadth of psychiatric risk factors evaluated relative to other non–clinician-administered measures. We examined the preliminary predictive validity of the Opioid Abuse Risk Screener relative to the widely used Scre...
Article
Full-text available
Background Two decades of human neuroimaging research have associated volume reductions in the hippocampus with posttraumatic stress disorder. However, little is known about the distribution of volume loss across hippocampal subfields. Recent advances in neuroimaging methods have made it possible to accurately delineate 10 gray matter hippocampal s...
Data
This manuscript (https://goo.gl/ea9UU9) includes an animated 3D video that was created (in Blender) using meshes from one of the combat control (non-PTSD) participants described in the manuscript. It demonstrates the gray matter subfields of the hippocampus, walking through each one to better visualize the more hidden areas. This video is an excell...
Poster
Full-text available
Background: The discovery of the rapid acting antidepressant effects of ketamine have generated considerable interest in academia and industry about the prospect of targeting NMDA receptors (NMDAR) in the treatment of refractory depression. However, the results from clinical trials failing to reach primary outcomes, combined with recent preclinical...
Poster
Full-text available
Abstract Background The hippocampus and amygdala have been repeatedly implicated in the psychopathology of posttraumatic stress disorder (PTSD). While numerous structural neuroimaging studies examined these two structures in PTSD, these analyses have largely been limited to volumetric measures. Recent advances in vertex-based neuroimaging methods h...
Poster
Full-text available
Abstract Background: Two decades of human neuroimaging research have associated volume reductions in the hippocampus with posttraumatic stress disorder. However, little is known about the distribution of volume loss across hippocampal subfields. Recent advances in neuroimaging methods have made it possible to accurately delineate 10 gray matter hip...
Article
Full-text available
Purpose of review: Although a fine-grained understanding of the neurobiology of posttraumatic stress disorder (PTSD) is yet to be elucidated, the last two decades have seen a rapid growth in the study of PTSD using neuroimaging techniques. The current review summarizes important findings from functional and structural neuroimaging studies of PTSD,...
Article
Full-text available
Background: Chronic stress and related physiological responses are known to have deleterious effects on neural integrity. Combat exposure is a notoriously pathogenic stressor and with over 2 million U.S. troops deployed to active combat zones since 2001, there is an urgent need to advance our understanding of its potential neural impact. Previous...
Article
Full-text available
Background: The hippocampus and amygdala have been repeatedly implicated in the psychopathology of posttraumatic stress disorder (PTSD). While numerous structural neuroimaging studies examined these two structures in PTSD, these analyses have largely been limited to volumetric measures. Recent advances in vertex-based neuroimaging methods have mad...
Article
Full-text available
Background: Prefrontal global brain connectivity with global signal regression (GBCr) was proposed as a robust biomarker of depression, and was associated with ketamine’s mechanism of action. Here, we investigated prefrontal GBCr in treatment-resistant depression (TRD) at baseline and following treatment. Then, we conducted a set of pharmacological...
Article
Full-text available
We investigated the extent of cortical thinning in U.S. Veterans exposed to combat who varied in the severity of their posttraumatic stress disorder (PTSD) symptoms. In addition, we explored the neural correlates of PTSD symptom dimensions and the interactive effects of combat exposure and PTSD upon cortical thickness. Sixty-nine combat exposed Vet...
Article
Full-text available
The anterior hippocampus (aHPC) has a central role in the regulation of anxiety-related behavior, stress response, emotional memory and fear. However, little is known about the presence and extent of aHPC abnormalities in posttraumatic stress disorder (PTSD). In this study, we used a multimodal approach, along with graph-based measures of global br...
Article
Full-text available
Posttraumatic stress disorder (PTSD) is a chronic and debilitating psychiatric disorder afflicting millions of individuals across the world. While the availability of robust pharmacologic interventions is quite lacking, our understanding of the putative neurobiological underpinnings of PTSD has significantly increased over the past two decades. Acc...