BLRD Research Career Scientist Award Application

Dr. Kimbrel is an experienced VA investigator with expertise in psychiatric genetics, suicide risk prediction, nonsuicidal self-injury, posttraumatic stress disorder (PTSD), and substance abuse. His program of research utilizes a wide array of research methods (e.g., genetic epidemiology, machine learning, clinical observation,

ecological momentary assessment, clinical trials) to investigate the phenomenology of these conditions. Genetic Risk Factors for Suicide. Dr. Kimbrel has led many of the largest genetic studies of suicidal thoughts and behaviors to date. His most recent study involved 633,778 Veteran participants and identified 16

novel genetic risk loci, including seven cross-ancestry risk loci. Nine additional ancestry-specific loci were also identified. Dr. Kimbrel’s team also recently conducted the largest epigenome-wide association study of DNA methylation in relation to suicide attempts to date. He is currently leading the largest genome-wide gene x

environment interaction study (GEWIS) of suicidal thoughts and behaviors to ever be attempted. Environmental Risk Factors for Suicide. Dr. Kimbrel is equally passionate about studying and identifying environmental risk factors for suicidal thoughts and behaviors, having also led numerous studies aimed at

identifying how psychiatric complexity and different forms of traumatic stress (e.g., combat exposure, military sexual trauma, childhood sexual trauma) contribute to risk for suicidal thoughts and behaviors among Veterans. More recently, his team has utilized sophisticated machine-learning approaches to study how

geospatial risk factors (e.g., altitude, rurality, social deprivation) contribute to suicide risk in Veterans. Improving Prediction of Acute Suicide Risk among Veterans. Dr. Kimbrel is presently MPI of four federally-funded projects utilizing machine-learning techniques and/or novel data sources to improve prediction

of suicide risk among Veterans. To date, Dr. Kimbrel’s team has developed: (1) natural language processing (NLP)-based approaches for extracting stressful life events and other suicide risk factors for Veterans from healthcare notes; (2) NLP-based approaches for estimating prevalence of uncoded suicide attempts; (3)

continuous-time probabilistic models to handle longitudinal EHR data assessed inconsistently over time; and (4) multiple AI-based models of risk for suicide attempts, suicide deaths, and all-cause mortality. Genetic and Environmental Contributions to PTSD and other Psychiatric Phenotypes. Dr. Kimbrel’s

research team has also studied the genetics of numerous other psychiatric phenotypes, including PTSD, depression, substance use disorders, hippocampal subfield volume, and cortical surface area and thickness. They are also actively involved in understanding how DNA methylation, gene expression, and various

measures of biological aging relate to psychiatric phenotypes. He has also led numerous investigations on environmental contributions to PTSD and other forms of psychopathology, particularly the role that different types of traumatic exposure may play in the pathogenesis of these conditions. Prediction and Prevention of Nonsuicidal Self-Injury (NSSI) among Veterans. Dr. Kimbrel is an

internationally-recognized authority on the subject of nonsuicidal self-injury (NSSI) among Veterans. His initial work on this topic found that NSSI was remarkably common among Veterans, a finding that has now been demonstrated in numerous other studies. His team has further demonstrated that NSSI is strongly associated

with suicidal ideation, suicide attempts, and interpersonal violence among Veterans. His team was also responsible for the development of the first and only validated measure of NSSI among Veterans. Cannabis Use among Veterans. Dr. Kimbrel has also led or else served as the senior author of four separate studies demonstrating associations between cannabis use and suicide attempts among Veterans. His

current work in this area involves conducting a VA-funded study aimed at evaluating the impact of reduced cannabis use on a variety of functional outcomes among Veterans with PTSD.