Nathan A Kimbrel

Nathan A Kimbrel
Duke University Medical Center | DUMC · Department of Psychiatry and Behavioral Science

PhD

About

223
Publications
47,699
Reads
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4,906
Citations
Citations since 2016
150 Research Items
4193 Citations
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20162017201820192020202120220200400600800
20162017201820192020202120220200400600800
20162017201820192020202120220200400600800
Introduction
My primary areas of interest include the etiology, assessment, and treatment of suicidal and nonsuicidal self-injury (NSSI), PTSD, depression, and substance use disorders. I primarily work with Veterans and Firefighters due to their high levels of occupational exposure to traumatic stress.
Additional affiliations
December 2018 - present
Duke University Medical Center
Position
  • Professor (Associate)
March 2017 - present
VA Mid-Atlantic Mental Illness, Research, Education, and Clinical Center
Position
  • Managing Director
January 2017 - present
Durham VA Medical Center
Position
  • Core Investigator, Durham HSR&D Center of Innovation
Education
July 2008 - July 2009
University of Mississippi Medical Center & Jackson VAMC
Field of study
  • Clinical Psychology
August 2005 - August 2009
University of North Carolina at Greensboro
Field of study
  • Clinical Psychology
August 2002 - August 2005
University of North Carolina at Greensboro
Field of study
  • Clinical Psychology

Publications

Publications (223)
Article
Full-text available
PTSD is a well-established risk factor for the full range of self-directed violence (SDV). It is also one of the few psychological conditions that distinguishes those who think about suicide from those who attempt suicide. Despite considerable evidence supporting these points, very little is understood about the mechanisms by which PTSD increases t...
Article
Full-text available
The Psychiatric Genomics Consortium-Posttraumatic Stress Disorder group (PGC-PTSD) combined genome-wide case-control molecular genetic data across 11 multiethnic studies to quantify PTSD heritability, to examine potential shared genetic risk with schizophrenia, bipolar disorder, and major depressive disorder and to identify risk loci for PTSD. Exam...
Article
The present research investigated wall/object punching as a form of nonsuicidal self-injury (NSSI) among 1,143 veterans seeking treatment for posttraumatic stress disorder (PTSD). Wall/object punching was remarkably common in this sample (43%), and its inclusion in the definition of NSSI increased estimated prevalence of recent NSSI by 14%. As expe...
Article
U.S. veterans are at increased risk for suicide compared to their civilian counterparts and account for approximately 20% of all deaths by suicide. Posttraumatic stress disorder (PTSD) and borderline personality features (BPF) have each been associated with increased suicide risk. Additionally, emerging research suggests that nonsuicidal self-injur...
Article
Posttraumatic stress disorder (PTSD) and alcohol use disorder (AUD) frequently co-occur and are associated with worse outcomes together than either disorder alone. A lack of consensus regarding recommendations for treating PTSD-AUD exists, and treatment dropout is a persistent problem. Acceptance and Commitment Therapy (ACT), a transdiagnostic, min...
Article
Firefighters protect the public despite significant risk to their health and well-being stemming from frequent trauma exposure and other occupational stressors. A minority of firefighters develop posttraumatic stress disorder (PTSD), alcohol use disorder (AUD), or related mental health problems, such as depression or anxiety. These problems frequen...
Article
Using a four-wave longitudinal design, three competing hypotheses (i.e., social selection, social causation, and reciprocal causation) were tested pertaining to the relation between social functioning and several indices of behavioral health [i.e., post-traumatic stress symptoms (PTSS), distress, and alcohol-related problems] among military veteran...
Article
Military service members and veterans (SMVs) are at risk for self-directed violence, including nonsuicidal self-injury (NSSI). While NSSI is an important construct worthy of independent study, it is understudied among SMVs and, when included in research, typically examined in the context of suicide risk. Consequently, lifetime prevalence rate estim...
Article
Full-text available
Cannabis use has been indicated as a risk factor for suicide in veterans. This study of Gulf War veterans tested the relationship between self-report past year cannabis use and (a) past year suicidal ideation and (b) risk for suicidal behavior. Data were from a national sample (N = 1126) of Gulf War veterans. Logistic regression models indicated ca...
Article
Military sexual assault (MSA) is a prevalent issue among military personnel that can have direct implications on postmilitary mental health. Gulf War era U.S. veterans represent the first cohort in which women veterans were integrated into most aspects of military service except for combat. The present study sought to build on prior studies by iden...
Preprint
Objective Suicidal behavior is moderately heritable and a major cause of death worldwide. Two large-scale genome-wide association studies (GWAS) have recently discovered and cross-validated genome-wide significant (GWS) loci for suicide attempts (SA). The current study leveraged the genetic cohorts from these two studies to conduct the largest GWAS...
Article
Depression and posttraumatic stress disorder (PTSD) are two of the most common mental health conditions experienced by veterans. It is unclear what individual and system level factors are associated with receiving mental health treatment for these concerns. Using a national sample of Gulf War Era veterans who endorsed lifetime diagnoses of either d...
Article
Suicide is a major public health problem affecting US Veterans and the US in general. Many variables (e.g., demographic, clinical, biological, geographic) have been associated with risk for suicide and suicidal behavior, including altitude; however, the exact nature of the relationship between altitude and suicide remains unclear in part due to the...
Article
Nonsuicidal self-injury (NSSI) is a robust predictor of suicidal thoughts and behaviors; however, while there are typically only small differences observed in the prevalence of NSSI between men and women, this condition has been largely overlooked and underestimated among men. Assessing NSSI methods more common in men may address misidentification...
Article
Complementary and integrative health (CIH) approaches have gained empirical support and are increasingly being utilized among veterans to treat a myriad of conditions. A cluster of medically unexplained chronic symptoms including fatigue, headaches, joint pain, indigestion, insomnia, dizziness, respiratory disorders, and memory problems, often refe...
Article
Analysis of longitudinal Electronic Health Record (EHR) data is an important goal for precision medicine. Difficulty in applying Machine Learning (ML) methods, either predictive or unsupervised, stems in part from the heterogeneity and irregular sampling of EHR data. We present an unsupervised probabilistic model that captures nonlinear relationshi...
Article
Prior research suggests a possible association between attention-deficit/hyperactivity disorder (ADHD) symptoms and nonsuicidal self-injury (NSSI) in veterans. However, this association has not yet been replicated. The present study sought to replicate and expand upon this association in a gender-balanced sample of veterans (N=124), more than half...
Preprint
Full-text available
Despite a global decrease in suicide rates in recent years, death by suicide has increased in the United States. It is therefore imperative to identify the risk factors associated with suicide attempts in order to combat this growing epidemic. In this study, we use an explainable artificial intelligence (X-AI) method, iterative Random Forest (iRF),...
Article
Full-text available
Genome-wide association studies (GWAS) identify genetic variants underlying complex traits but are limited by stringent genome-wide significance thresholds. Here we dramatically relax GWAS stringency by orders of magnitude and apply GRIN (Gene set Refinement through Interacting Networks), which increases confidence in the expanded gene set by retai...
Article
Background Posttraumatic stress disorder (PTSD) and alcohol use disorder (AUD) are each common among Unites States (U.S.) military veterans and frequently co-occur (i.e., PTSD+AUD). Although comorbid PTSD+AUD is generally associated with worse outcomes relative to either diagnosis alone, some studies suggest the added burden of comorbid PTSD+AUD is...
Article
Background Posttraumatic stress disorder (PTSD) is heritable and a potential consequence of exposure to traumatic stress. Evidence suggests that a quantitative approach to PTSD phenotype measurement and incorporation of lifetime trauma exposure (LTE) information could enhance the discovery power of PTSD genome-wide association studies (GWAS). Meth...
Article
Full-text available
To identify pan-ancestry and ancestry-specific loci associated with attempting suicide among veterans, we conducted a genome-wide association study (GWAS) of suicide attempts within a large, multi-ancestry cohort of U.S. veterans enrolled in the Million Veterans Program (MVP). Cases were defined as veterans with a documented history of suicide atte...
Article
The onset and persistence of life events (LE) such as housing instability, job instability, and reduced social connection have been shown to increase risk of suicide. Predictive models for suicide risk have low sensitivity to many of these factors due to under-reporting in structured electronic health records (EHR) data. In this study, we show how...
Article
Introduction: Nonsuicidal self-injury (NSSI) is associated with significant impairment and is a robust predictor of suicidal ideation, attempts, and death by suicide; however, the present lack of a brief screening instrument for NSSI coupled with consistent underidentification of NSSI in male adults has led to concerning rates of missed identifica...
Article
Purpose Posttraumatic Stress Disorder (PTSD) is associated with increased alcohol use and alcohol use disorder (AUD), which are all moderately heritable. Studies suggest the genetic association between PTSD and alcohol use differs from that of PTSD and AUD, but further analysis is needed. Basic Procedures We used genomic Structural Equation Modeli...
Article
Ecological momentary assessment (EMA) is a useful tool to investigate antecedents and consequences of nonsuicidal self-injury (NSSI), a robust predictor of Veteran suicide risk. Despite elucidating temporal changes among dynamic variables, EMA remains underutilized to study NSSI among veterans, perhaps due to concerns of safety and utility. The pre...
Preprint
The onset and persistence of life events (LE) such as housing instability, job instability, and reduced social connection have been shown to increase risk of suicide. Predictive models for suicide risk have low sensitivity to many of these factors due to under-reporting in structured electronic health records (EHR) data. In this study, we show how...
Preprint
Suicide is a major public health problem affecting US Veterans and the US in general. Many variables (e.g., demographic, clinical, biological, geographic) have been associated with risk for suicide and suicidal behavior, including altitude; however, the exact nature of the relationship between altitude and suicide remains unclear in part due to the...
Article
Nonsuicidal self-injury (NSSI) has been identified as one of the strongest predictors of suicide attempts. Wall/object punching is a particularly prevalent form of NSSI among male veterans that has been linked to both impulsivity and anger. The objective of the present study was to examine the indirect effect of impulsivity on wall/object punching...
Preprint
Analysis of longitudinal Electronic Health Record (EHR) data is an important goal for precision medicine. Difficulty in applying Machine Learning (ML) methods, either predictive or unsupervised, stems in part from the heterogeneity and irregular sampling of EHR data. We present an unsupervised probabilistic model that captures nonlinear relationshi...
Article
Full-text available
The volume of subcortical structures represents a reliable, quantitative, and objective phenotype that captures genetic effects, environmental effects such as trauma, and disease effects such as posttraumatic stress disorder (PTSD). Trauma and PTSD represent potent exposures that may interact with genetic markers to influence brain structure and fu...
Article
Background The affective states most strongly associated with nonsuicidal self-injury (NSSI) remain poorly understood, particularly among veterans. This study used ecological momentary assessment (EMA) to examine relationships between affect ratings and NSSI urges and behaviors among veterans with NSSI disorder. Methods Participants (N = 40) compl...
Article
Full-text available
Child maltreatment is a well-established risk factor for suicide attempts, but research on mechanisms accounting for this relationship is needed. The current study examined the indirect effects of posttraumatic stress disorder (PTSD) symptoms and alcohol misuse in the relationship between childhood maltreatment and suicidal ideation. In the current...
Article
A substantial minority of deployed Gulf War veterans developed posttraumatic stress disorder (PTSD), depression, and several chronic illnesses. Although military combat and exposure to certain nuclear, biological, and chemical agents (NBCs) increase risk for post-deployment health problems, they do not fully explain many Gulf War veteran health dia...
Article
Objectives As a malleable risk-factor, psychological inflexibility is implicated in the development and maintenance of posttraumatic stress symptoms (PTS). Unfortunately, limited research has addressed whether changes in psychological inflexibility are antecedent to changes in PTS severity over time, or whether such changes are mutually dependent....
Article
Full-text available
Background Suicide is a leading cause of death worldwide, and non-fatal suicide attempts, which occur far more frequently, are a major source of disability and social and economic burden. Both have substantial genetic etiology, which is partially shared and partially distinct from that of related psychiatric disorders. Methods We conducted a genom...
Article
Full-text available
Background Worldwide, nearly 800,000 individuals die by suicide each year; however, longitudinal prediction of suicide attempts remains a major challenge within the field of psychiatry. The objective of the present research was to develop and evaluate an evidence-based suicide attempt risk checklist [i.e., the Durham Risk Score (DRS)] to aid clinic...
Article
Full-text available
Posttraumatic stress disorder (PTSD) is a complex psychiatric disorder that can develop following exposure to traumatic events. The Psychiatric Genomics Consortium PTSD group (PGC-PTSD) has collected over 20,000 multi-ethnic PTSD cases and controls and has identified both genetic and epigenetic factors associated with PTSD risk. To further investig...
Article
Due to occupational stress and exposure to potentially traumatic events, firefighters are at an increased risk for the development of many behavioral health conditions. While volunteer and career firefighters represent two distinct subgroups, little research has examined differences in the availability of, and barriers to, behavioral health care be...
Article
An association has been found between cannabis use disorder (CUD) and violence in several clinical populations, including veterans with posttraumatic stress disorder (PTSD), and there is evidence that CUD has been increasing among veterans since September 11, 2001. There is also evidence that some veterans may be attempting to self-medicate psychol...
Article
Full-text available
Growing research suggests that posttraumatic stress disorder (PTSD) may be a risk factor for poor cardiovascular health, and yet our understanding of who might be at greatest risk of adverse cardiovascular outcomes after trauma is limited. In this study, we conducted the first examination of the individual and synergistic contributions of PTSD symp...
Article
Full-text available
While repetitive transcranial magnetic stimulation (rTMS) is widely used to treat psychiatric disorders, innovations are needed to improve its efficacy. An important limitation is that while psychiatric disorders are associated with fronto-limbic dysregulation, rTMS does not have sufficient depth penetration to modulate affected subcortical structu...
Article
Suicidal ideation (SI) is a prevalent issue in the veteran population. A number of factors have been identified as risk factors for suicidal ideation (SI) in veterans, including suicide attempts, depression, posttraumatic stress disorder (PTSD), and drug use. However, clinicians’ ability to predict suicide is poor, particularly given the interplay...
Article
Background : Expanding on research that has identified nonsuicidal self-injury (NSSI) as a strong predictor of suicide risk, the present study examined NSSI disorder (NSSID) and borderline personality disorder (BPD) as unique contributors to lifetime suicide attempts. To our knowledge, the present study represents the first exploration of these ass...
Article
Background: Head injuries are common injury in the fire service; however, very little data exist on the risks this may pose to the development of post-traumatic stress disorder (PTSD) and depression in this high-risk population. Aims: Our study aimed to compare levels of PTSD and depression symptoms in firefighters with a line-of-duty head injur...
Article
Background While firefighter‐emergency medical responders (FF‐EMR) are important stakeholders in cities considering the implementation of a supervised injection facility (SIF), there is little information on perspectives of first responders who serve these communities. The aim of the present study was to identify FF‐EMR perspectives on working near...
Article
Up to 14% of veterans engage in nonsuicidal self-injury (NSSI) in their lifetime and this behavior is a relatively strong predictor of suicidal behavior compared to other identified risk factors. Further, NSSI is a clinically relevant behavior in its own right; it is associated with more severe psychopathology as well as bodily harm that sometimes...
Article
Veterans have high rates of suicide, and nonsuicidal self-injury (NSSI) is one of the strongest predictors of suicide risk; however, there is presently little known about antecedents of NSSI that might inform intervention efforts. Accumulating research suggests that anger and hostility play an important role in NSSI, but whether these emotions prec...
Article
Objective: Firefighters are an important sample of convenience to study traumatic exposure and symptom development. This study assessed trauma exposure inside and outside of fire service, diagnosed posttraumatic stress disorder (PTSD) and associated disorders using clinical interviews and self-report measures, then tested the hypothesis that trauma...
Article
Full-text available
Behavioural, structural, and functional neuroimaging have implicated the hippocampus as a critical brain region in posttraumatic stress disorder (PTSD) pathogenesis. Recent work in a normative, primarily European, sample identified 15 unique genetic loci contributing to structural variability in six hippocampal subfield volumes. We explored the rel...
Article
With its recent inclusion in the Diagnostic and Statistical Manual, nonsuicidal self-injury disorder (NSSID) has received limited research attention, especially in samples of military veterans. The present study sought to identify diagnostic predictors of NSSID within a veteran sample. Study participants included 124 veterans with at least one psyc...
Article
Full-text available
Epigenetic differences may help to distinguish between PTSD cases and trauma-exposed controls. Here, we describe the results of the largest DNA methylation meta-analysis of PTSD to date. Ten cohorts, military and civilian, contribute blood-derived DNA methylation data from 1,896 PTSD cases and trauma-exposed controls. Four CpG sites within the aryl...
Article
Firefighters (FFs) protect the public despite significant risks to their health and well‐being stemming from frequent trauma exposure and other occupational stressors. A minority of FFs develop posttraumatic stress disorder (PTSD) or related mental health problems, whereas most remain remarkably resilient despite enormous stress. This points toward...
Article
Recent advances in genetic research and technology are permitting researchers to identify the genetic basis of awe wide array of health conditions for the first time. In addition, improved understanding of the field of epigenetics is rapidly shaping understanding of how environmental factors and behavioral changes can fundamentally alter gene expre...
Preprint
Full-text available
Repetitive transcranial magnetic stimulation (rTMS) has fundamentally transformed how we treat psychiatric disorders, but is still in need of innovation to optimally correct dysregulation that occurs throughout the fronto-limbic network. rTMS is often applied over the prefrontal cortex, a central node in this network, but less attention is given to...
Article
Posttraumatic stress disorder (PTSD) clinics in the Department of Veterans Affairs (VA) often provide psychoeducational or skill-building groups to prepare veterans for trauma-focused PTSD treatments. However, there has been limited evaluation of the effectiveness of this phase-based approach for treatment engagement and symptom reduction. Particip...
Article
Objective Previous studies of military veterans have produced mixed findings regarding whether combat exposure is directly related to suicidal ideation or is indirectly related to suicidal ideation via its influence on other factors. The present study used a longitudinal design to test the hypothesis that post‐traumatic stress disorder (PTSD) sympt...
Article
This PRISMA scoping review explores existing research conducted with United States military samples utilizing ecological momentary assessment (EMA) to evaluate mental health outcomes. EMA facilitates understanding of temporal changes of dynamic variables subject to change difficult to capture in standard laboratory assessment. It also elucidates un...
Article
Objective This study explored the boundaries of the proposed diagnostic criteria for nonsuicidal self‐injury disorder (NSSID) as outlined in the Conditions for Further Study section of the Diagnostic and Statistical Manual, Fifth Edition . We sought to falsify the exclusion of certain NSSI behaviors from a diagnosis of NSSID (Criterion D), arguing...
Article
Background: Mild traumatic brain injury (mTBI) is a nationwide problem; yet, no firefighter mTBI data are available. Methods: In this cross-sectional study, we assessed retrospective head injuries using WHO guidelines. We captured mTBI frequency and examined firefighters’ symptoms (e.g., using Ohio State University Traumatic Brain Injury Identifica...
Article
Although military sexual assault (MSA) has been well established as a risk factor for psychopathology (e.g., PTSD, depression), little research has examined the association between MSA and self- and other-directed violence. Furthermore, there has been a growing empirical focus on potential gender differences in the effects of MSA, but few of these...
Article
Sexual assault is associated with increased psychological distress. It is possible that military sexual assault (MSA) is associated with heightened psychological distress compared to adult sexual assault that occurs pre- or postmilitary service due to the nature of the military setting. Veterans and service members (N = 3,114; 19.6% women) who part...
Article
Full-text available
Background: Previous studies using candidate gene and genome-wide approaches have identified epigenetic changes in DNA methylation (DNAm) associated with posttraumatic stress disorder (PTSD). Methods: In this study, we performed an EWAS of PTSD in a cohort of Veterans (n = 378 lifetime PTSD cases and 135 controls) from the Translational Research...
Article
Background: Limited research suggests that female firefighters report problem drinking at higher rates than the general population. Aims: To identify longitudinal drinking patterns in female firefighters, make comparisons to male firefighters and examine problem drinking in relation to post-traumatic stress disorder (PTSD) and depression. Metho...