Physiologic Stress and Epigenetic Mechanisms that Precipitate Risk for Suicidal Behavior in Nurses

PROJECT SUMMARY/ABSTRACT The rate of suicide in nurses has reached alarming proportions, with recent estimates upward of 17.1 suicides per 100,000 nurses each year—almost double that of the general population (8.6/100,000). Proposed is a program of training and research using longitudinal design to investigate the associations among individual (e.g., subjective mood, lifetime trauma) and work environment characteristics (e.g., shift type and duration); life stressors (e.g., discrimination, lateral violence); and suicidal ideation or behavior in nurses. Whereas previous research about suicide in nurses has been limited to postmortem data, cross-sectional studies or self-report stress measures, the proposed project will collect longitudinal data and will use physiologic stress biomarkers (hair cortisol) and epigenetics (DNA methylation) to better establish the temporal sequence of potential nursing-specific risk factors (individual characteristics, life stressors, physiologic stress, and work environment characteristics), and suicidal ideation or behavior in real-world clinical settings. Sleep will be tested as a potential modifiable protective factor, as will nurse work environment characteristics (e.g., day vs. night shift). Hair cortisol concentrations measure cumulative cortisol release and reflect past months of stress exposure, thus avoiding diurnal variation effects and permitting the longitudinal investigation of real-world individual and environmental exposures. Grounded in the Stress-Diathesis Model of Suicidal Behavior, we will recruit 100 nurses to undergo a series of psychological interviews (e.g., SCID-5-RV and Iowa Gambling Task), quantitative survey measures using validated instruments, and hair cortisol concentrations every 3 months for 1 year. Further, we will explore genome-scale epigenetic mechanisms that potentiate harmful DNA methylation on unique gene alleles, which exacerbate suicidal ideation or behavior and can potentially help us to better understand genetic expression of stress adaptation in the search for biological mechanisms. We aim to identify modifiable individual and work environment characteristics that could mitigate suicidal ideation or behavior, even for those at high genetic risk. We will use a range of analytical strategies selected to test interactions and moderating effects including latent growth curve modeling. The proposed research will be complemented by experiential and didactic training, along with expert mentorship in the fields of (1) physiologic stress measurement, (2) suicidology, (3) epigenetics/DNA methylation, (4) longitudinal analysis, and (5) professional development and dissemination of findings. Results of this K08 application will yield data needed to inform final variables and measures and a power analysis for a planned R01 submission in Year 5 that proposes a large- scale longitudinal study in nurses. Overall, this K08 funding would support my path to research independence and my overall goal of building evidence to better identify high-risk individuals for suicide and to inform the development of individualized suicide prevention interventions in nurses and similar frontline workforce.