Stefanie E. Mayer

Modeling neuroendocrine stress reactivity in salivary cortisol: adjusting for peak latency variability.

Abstract In this report, we present growth curve modeling (GCM) with landmark registration as an alternative statistical approach for the analysis of time series cortisol data. This approach addresses an often-ignored but critical source of variability in salivary cortisol analyses: individual and group differences in the time latency of post-stress peak concentrations. It allows for the simultaneous examination of cortisol changes before and after the peak while controlling for timing differences, and thus provides additional information that can help elucidate group differences in the underlying biological processes (e.g. intensity of response, regulatory capacity). We tested whether GCM with landmark registration is more sensitive than traditional statistical approaches (e.g. repeated measures ANOVA – rANOVA) in identifying sex differences in salivary cortisol responses to a psychosocial stressor (Trier Social Stress Test –TSST) in healthy adults (mean age 23). We used plasma ACTH measures as our “standard” and show that the new approach confirms in salivary cortisol the ACTH finding that males had longer peak latencies, higher post-stress peaks but a more intense post-peak decline. This finding would have been missed if only saliva cortisol was available and only more traditional analytic methods were used. This new approach may provide neuroendocrine researchers with a highly sensitive complementary tool to examine the dynamics of the cortisol response in a way that reduces risk of false negative findings when blood samples are not feasible.

Trait and state rumination interact to prolong cortisol activation to psychosocial stress in females

There is a growing realization that cognitive processes associated with stress coping, such as rumination and distraction, can impact the hypothalamic-pituitary-adrenal-axis (HPA-axis). Yet, little is known about what aspects of the HPA-axis stress response (rate of activation, duration of activation, rate of recovery) is impacted by such cognitive processes. This study examines the impact of both ruminative trait tendencies and experimentally induced rumination on salivary cortisol responses to a social evaluative stress task. Participants (n=71) were exposed to the Trier Social Stress Test (TSST) and were then randomized to complete either a rumination or distraction task. Trait rumination was also assessed at baseline. Results showed no main effects of either trait rumination or experimental condition, but they interacted to predict the cortisol response. Specifically, participants high in trait rumination had prolonged duration of cortisol activation in the rumination condition, compared to those in the distraction condition. In contrast, cortisol responses of participants with low trait rumination did not differ by condition. Notably, our interaction effect was only significant in females. Our findings highlight the complex relationship between rumination and HPA-axis activity, suggesting an interaction of trait and state rumination in shaping HPA-axis responses to stress, and call attention to sex differences in this relationship.

More than a feeling: A unified view of stress measurement for population science

Stress can influence health throughout the lifespan, yet there is little agreement about what types and aspects of stress matter most for human health and disease. This is in part because “stress” is not a monolithic concept but rather, an emergent process that involves interactions between individual and environmental factors, historical and current events, allostatic states, and psychological and physiological reactivity. Many of these processes alone have been labeled as “stress.” Stress science would be further advanced if researchers adopted a common conceptual model that incorporates epidemiological, affective, and psychophysiological perspectives, with more precise language for describing stress measures. We articulate an integrative working model, highlighting how stressor exposures across the life course influence habitual responding and stress reactivity, and how health behaviors interact with stress. We offer a Stress Typology articulating timescales for stress measurement – acute, event-based, daily, and chronic – and more precise language for dimensions of stress measurement.

Effortful control and context interact in shaping neuroendocrine stress responses during childhood

Trait and contextual factors can shape individual and group differences in hypothalamic-pituitary-adrenal (HPA) response to stress; but the ways in which these factors may interact with each other to modulate stress activity have rarely been examined. Here, we investigated whether the association between a temperamental self-regulatory trait - Effortful Control (EC) - and HPA axis stress response is moderated by type of laboratory stress in sixty-five children (35 boys). EC was measured at ages 3 and 6 using age-appropriate laboratory batteries as well as mother reports. HPA axis responses were measured at age 7 by randomly assigning children to one of two laboratory stress tasks (frustration vs. fear). Results indicated that EC interacted with stress context in predicting cortisol response. Specifically, lower EC was associated with greater cortisol response (steeper reactivity slopes) in the context of a frustration stressor but this was reversed in a fear context where lower EC was associated with flatter, more gradual activation. It is likely that different components of EC, such as emotion regulation and attention, differentially interact with the stress context. These types of effects and interactions need to be more thoroughly understood in order to meaningfully interpret cortisol reactivity data and better characterize the role of the HPA axis in human psychopathology.

Chronic stress, hair cortisol and depression: A prospective and longitudinal study of medical internship

BACKGROUND Stress plays a causal role in depression onset, perhaps via alteration of hypothalamic-pituitary-adrenal (HPA) axis functioning. HPA axis hyperactivity has been reported in depression, though inconsistently, and the nature of this relationship remains unclear, partly because cortisol measurement over time has been challenging. Development of hair cortisol assessment, a method that captures cortisol over prolonged periods of time, creates new possibilities. In this study, hair cortisol was incorporated into a prospective and longitudinal study of medical internship, stress and symptoms of depression. This provided a rare opportunity to 1) prospectively assess hair cortisol responses to stress, and 2) examine whether stress-induced changes in hair cortisol predict depressive symptom development. METHODS Hair cortisol, depressive symptoms, and stress-relevant variables (work hours, sleep, perceived stress, mastery/control) were assessed in interns (n = 74; age 25-33) before and repeatedly throughout medical internship. RESULTS Hair cortisol sharply increased with stressor onset, decreased as internship continued, and rose again at years end. Depressive symptoms rose significantly during internship, but were not predicted by cortisol levels. Hair cortisol also did not correlate with increased stressor demands (work hours, sleep) or stress perceptions (perceived stress, mastery/control); but these variables did predict depressive symptoms. DISCUSSION Hair cortisol and depressive responses increased with stress, but they were decoupled, following distinct trajectories that likely reflected different aspects of stress reactivity. While depressive symptoms correlated with stressor demands and stress perceptions, the longitudinal pattern of hair cortisol suggested that it responded to contextual features related to anticipation, novelty/familiarity, and social evaluative threat.

The Cortisol Awakening Response and Depressive Symptomatology: The Moderating Role of Sleep and Gender

The association between depression and the cortisol awakening response (CAR) has been widely examined, yet the results are mixed and factors responsible for such inconsistencies are poorly understood. The current study investigated whether the link between depressive symptomatology and CAR varied as a function of two such factors: sleep and gender. The sample included 58 young adults (30 females; Mage  = 18.7; SDage  = 0.91). Participants completed the Beck Depression Inventory as well as the Consensus Sleep Diary to assess depressive symptomatology and daily sleep patterns, respectively. Participants also provided four salivary cortisol samples (0, 30, 45 and 60 min after awakening) during two consecutive weekdays. Results demonstrated that greater depressive symptoms were associated with a greater CAR but only when depressive symptoms were linked to a shorter sleep time. In addition, gender significantly moderated the association between depressive symptoms and CAR. While greater depressive symptoms were associated with an elevated CAR among females, they were associated with a blunted CAR among males. These findings provide some insight into potential mechanisms linking depressive symptomatology and CAR, and suggest that future studies examining CAR as a biomarker of depression should account for differences in sleep and gender. Copyright

Mediators of compassionate goal intervention effects on human neuroendocrine responses to the Trier Social Stress Test

Abstract Objectives: The hypothalamic-pituitary-adrenal (HPA) axis is thought to mediate the effects of stress on illness. Research has identified a limited number of psychological variables that modulate human HPA responses to stressors (e.g. perceived control and social support). Prosocial goals can reduce subjective stress, but have not been carefully examined in experimental settings where pathways of impact on biological stress markers may be traced. Recent work demonstrated that coaching individuals to strive to help others reduced HPA responses to the Trier Social Stress Test (TSST) relative to other cognitive interventions. However, identification of mediational pathways, which were not examined in the original study, is necessary to determine whether the HPA buffering effects were due to helping motivations (compassionate goals; CGs) rather than via previously identified variables such as control or support. Methods: In this new analysis, we combined the original cortisol data with novel observer ratings of interpersonal behavior and psychological variables during the stress task, and conducted new, theory-driven analyses to determine psychological mediators for the interventions effect on cortisol responses (N = 54; 21 females, 33 males; 486 cortisol samples). Results: Control, support, and task ego-threat failed to account for the effects of the intervention. As hypothesized, self and observer-rated CGs, as well as observer-rated perceptions of participants’ interpersonal behavior as morally desirable (but not as dominant or affiliative) were significant mediators of neuroendocrine responses. Conclusions: The findings suggest that stress-reduction interventions based on prosocial behavior should target particular motivational and interpersonal features.