Biomarker Studies in Stress Biology: From the Gene to Population, from the Organism to the Application

Endpoints assessed at the population or community level are most often the result of the sum of effects on individuals, arising from the effects at the cellular and molecular levels. Within this framework, these lower biological level endpoints are more responsive at an early stage of exposure, making them potential toolboxes to be used as early-warning markers to address stress. Given this, by linking responses and understanding organisms’ metabolism and physiology, the possibilities for the use of biomarkers in stress biology are vast. Here, biomarker comprehensive examples are given to enlighten the need to link levels of biological organization, and their usefulness for a myriad of fields and applications is presented and discussed.

Racial discrimination and ethnic racial identity in adolescence as modulators of HPA axis activity

We review evidence of racial discrimination as a critical and understudied form of adversity that has the potential to impact stress biology, particularly hypothalamic–pituitary–adrenal (HPA) axis activity. We highlight ethnic racial identity (ERI) as a positive regulatory influence on HPA axis activity, as indexed by levels of salivary cortisol. In past research by our group, Black individuals with high adolescent discrimination had low adult cortisol levels (hypocortisolism). Here, we present new analyses showing that ERI, measured prospectively from ages 12 through 32 in 112 Black and white individuals, is related to better-regulated cortisol levels in adulthood, particularly for Black participants. We also describe ongoing research that explores whether the promotion of ERI during adolescence can reduce ethnic–racial disparities in stress biology and in emotional health and academic outcomes.

The Promises and the Challenges of Integrating Multi-Omics and Systems Biology in Comparative Stress Biology

Comparative stress biology is inherently a systems biology approach with the goal of integrating the molecular, cellular, and physiological responses with fitness outcomes. In this way, the systems biology approach is expected to provide a holistic understanding of how different stressors result in different fitness outcomes, and how different individuals (or populations or species) respond to stressors differently. In this perceptive article, I focus on the use of multiple types of -omics data in stress biology. Targeting students and those researchers who are considering integrating -omics approaches in their comparative stress biology studies, I discuss the promise of the integration of these measures for furthering our holistic understanding of how organisms respond to different stressors. I also discuss the logistical and conceptual challenges encountered when working with -omics data and the current hurdles to fully utilize these data in studies of stress biology in non-model organisms.

Stress Allostasis in Substance Use Disorders: Promise, Progress, and Emerging Priorities in Clinical Research

Clinicians and researchers alike have long believed that stressors play a pivotal etiologic role in risk, maintenance, and/or relapse of alcohol and other substance use disorders (SUDs). Numerous seminal and contemporary theories on SUD etiology posit that stressors may motivate drug use and that individuals who use drugs chronically may display altered responses to stressors. We use foundational basic stress biology research as a lens through which to evaluate critically the available evidence to support these key stress–SUD theses in humans. Additionally, we examine the field's success to date in targeting stressors and stress allostasis in treatments for SUDs. We conclude with our recommendations for how best to advance our understanding of the relationship between stressors and drug use, and we discuss clinical implications for treatment development.