Treatment-Resistant Blunted HPA Activity, but Reversible Cardiovascular Stress Reactivity in Young Women With Eating Disorders

Between- and within-person effects of stress on emotional eating in women: a longitudinal study over 49 days

BACKGROUND

Stress is associated with binge eating and emotional eating (EE) cross-sectionally. However, few studies have examined stress longitudinally, limiting understanding of how within-person fluctuations in stress influence EE over time and whether stress is a risk factor or consequence of EE. Additionally, little is known regarding how the biological stress response relates to EE.

METHODS

We used an intensive, longitudinal design to examine between-person and within-person effects of major life stress, daily stress, and cortisol on EE in a population-based sample of women (N = 477; ages 15-30; M = 21.8; s.d. = 3.0) from the Michigan State University Twin Registry. Participants reported past year major life stress, then provided daily ratings of EE and stress for 49 consecutive days. Hair cortisol concentration (HCC) was collected as a longitudinal biological stress measure.

RESULTS

Women reported greater EE when they experienced greater mean stress across days (between-person effects) or greater stress relative to their own average on a given day (within-person effects). Daily stress was more strongly associated with EE than major life stress. However, the impact of daily stress on EE was amplified in women with greater past year major life stress. Finally, participants with lower HCC had increased EE.

CONCLUSIONS

Findings confirm longitudinal associations between stress and EE in women, and highlight the importance of within-person shifts in stress in EE risk. Results also highlight HCC as a novel biological stress measure that is significantly associated with EE and may overcome limitations of prior physiological stress response indicators.

Targeting the Arginine Vasopressin V1b Receptor System and Stress Response in Depression and Other Neuropsychiatric Disorders

A healthy stress response is critical for good mental and overall health and promotes neuronal growth and adaptation, but the intricately balanced biological mechanisms that facilitate a stress response can also result in predisposition to disease when that equilibrium is disrupted. The hypothalamic-pituitary-adrenal (HPA) axis neuroendocrine system plays a critical role in the body's response and adaptation to stress, and vasopressinergic regulation of the HPA axis is critical to maintaining system responsiveness during chronic stress. However, exposure to repeated or excessive physical or emotional stress or trauma can shift the body's stress response equilibrium to a "new normal" underpinned by enduring changes in HPA axis function. Exposure to early life stress due to adverse childhood experiences can also lead to lasting neurobiological changes, including in HPA axis function. HPA axis impairment in patients with depression is considered among the most reliable findings in biological psychiatry, and chronic stress has been shown to play a major role in the pathogenesis and onset of depression and other neuropsychiatric disorders. Modulating HPA axis activity, for example via targeted antagonism of the vasopressin V_1b receptor, is a promising approach for patients with depression and other neuropsychiatric disorders associated with HPA axis impairment. Despite favorable preclinical indications in animal models, demonstration of clinical efficacy for the treatment of depressive disorders by targeting HPA axis dysfunction has been challenging, possibly due to the heterogeneity and syndromal nature of depressive disorders. Measures of HPA axis function, such as elevated cortisol levels, may be useful biomarkers for identifying patients who may benefit from treatments that modulate HPA axis activity. Utilizing clinical biomarkers to identify subsets of patients with impaired HPA axis function who may benefit is a promising next step in fine-tuning HPA axis activity via targeted antagonism of the V_1b receptor.

Inducing and Recording Acute Stress Responses on a Large Scale With the Digital Stress Test (DST): Development and Evaluation Study

Background

Valuable insights into the pathophysiology and consequences of acute psychosocial stress have been gained using standardized stress induction experiments. However, most protocols are limited to laboratory settings, are labor-intensive, and cannot be scaled to larger cohorts or transferred to daily life scenarios.

Objective

We aimed to provide a scalable digital tool that enables the standardized induction and recording of acute stress responses in outside-the-laboratory settings without any experimenter contact.

Methods

On the basis of well-described stress protocols, we developed the Digital Stress Test (DST) and evaluated its feasibility and stress induction potential in a large web-based study. A total of 284 participants completed either the DST (n=103; 52/103, 50.5% women; mean age 31.34, SD 9.48 years) or an adapted control version (n=181; 96/181, 53% women; mean age 31.51, SD 11.18 years) with their smartphones via a web application. We compared their affective responses using the international Positive and Negative Affect Schedule Short Form before and after stress induction. In addition, we assessed the participants’ stress-related feelings indicated in visual analogue scales before, during, and after the procedure, and further analyzed the implemented stress-inducing elements. Finally, we compared the DST participants’ stress reactivity with the results obtained in a classic stress test paradigm using data previously collected in 4 independent Trier Social Stress Test studies including 122 participants overall.

Results

Participants in the DST manifested significantly higher perceived stress indexes than the Control-DST participants at all measurements after the baseline (P<.001). Furthermore, the effect size of the increase in DST participants’ negative affect (d=0.427) lay within the range of effect sizes for the increase in negative affect in the previously conducted Trier Social Stress Test experiments (0.281-1.015).

Conclusions

We present evidence that a digital stress paradigm administered by smartphone can be used for standardized stress induction and multimodal data collection on a large scale. Further development of the DST prototype and a subsequent validation study including physiological markers are outlined.

Sensor technology in eating disorders research: A systematic review

OBJECTIVE

Sensor technologies offer exciting potential to objectively measure psychopathological correlates of eating pathology and eating disorder (ED) research utilizing sensors has rapidly proliferated in the past several years. The aims of the present review are: (1) characterize the types of sensors that have been utilized in ED research, (2) identify the psychopathological factors relevant to EDs that have been assessed using sensors, (3) describe the data supporting the validity and reliability of these sensors, (4) discuss limitations associated with these sensors, and (5) identify gaps that persist within the ED literature with regard to use of sensor technologies.

METHOD

A systematic search was conducted of PubMed, PsycINFO, Web of Science, ProQuest, and "gray" literature sources. Eligible publications were empirical studies that utilized sensors to measure at least one psychological variable among clinical ED populations.

RESULTS

Sensors have been utilized with ED samples to measure eating behaviors, physical activity, sleep, autonomic nervous system activity, eyeblink startle response, visual attention, and visual-haptic object integration. The reliability and validity of these sensors varies widely and there are a number of significant gaps that remain in the literature with regard to the types of sensors utilized, context in which sensors have been used, and populations studied.

DISCUSSION

The existing literature utilizing sensors within ED research largely support the feasibility and acceptability of these tools. Sensors should continue to be utilized within the field, with a specific focus on examining the reliability and validity of these tools within ED samples and increasing the diversity of samples studied.

PUBLIC SIGNIFICANCE STATEMENT

Sensor technologies, such as those included in modern smartwatches, offer new opportunities to measure factors that may maintain or contribute to symptoms of eating disorders. This article describes the types of sensors that have been used in eating disorders research, challenges that may arise in using these sensors, and discusses new applications of these sensors that may be pursued in future research.

Stress-induced alterations in HPA-axis reactivity and mesolimbic reward activation in individuals with emotional eating

BACKGROUND

Emotional eating has emerged as a contributing factor to overeating, potentially leading to obesity or disordered eating behaviors. However, the underlying biological mechanisms related to emotional eating remain unclear. The present study examined emotional, hormonal, and neural alterations elicited by an acute laboratory stressor in individuals with and without emotional eating.

METHODS

Emotional (n = 13) and non-emotional eaters (n = 15) completed two main study visits, one week apart: one visit included a Stress version and the other a No-stress version of the Maastricht Acute Stress Task (MAST). Immediately pre- and post-MAST, blood was drawn for serum cortisol and participants rated their anxiety level. After the MAST, participants completed a Food Incentive Delay (FID) task during functional magnetic resonance imaging (fMRI), followed by an ad libitum snack period.

RESULTS

Emotional eaters exhibited elevated anxiety (p = 0.037) and cortisol (p = 0.001) in response to the Stress MAST. There were no changes in anxiety or cortisol among non-emotional eaters in response to the Stress MAST or in either group in response to the No-stress MAST. In response to the Stress MAST, emotional eaters exhibited reduced activation during anticipation of food reward in mesolimbic reward regions (caudate: p = 0.014, nucleus accumbens: p = 0.022, putamen: p = 0.013), compared to non-emotional eaters. Groups did not differ in snack consumption.

CONCLUSIONS

These data indicate disrupted neuroendocrine and neural responsivity to psychosocial stress amongst otherwise-healthy emotional eaters, who demonstrated hyperactive HPA-axis response coupled with hypoactivation in reward circuitry. Differential responsivity to stress may represent a risk factor in the development of maladaptive eating behaviors.

Stability and test-retest reliability of different hormonal stress markers upon exposure to psychosocial stress at a 4-month interval

The Trier Social Stress Test (TSST) has been shown to reliably induce physiological stress responses in the hypothalamus-pituitary-adrenal (HPA) and in the sympathetic-adrenal-medullary (SAM) axis in cross-sectional studies. However, it was also reported that repeated exposure to the TSST might be associated with habituation, mainly of the HPA axis responsivity. Thus, in all longitudinal stress studies involving repeated TSST administration, potential habituation of the HPA axis response complicates the interpretation of results. The goal of the present study was therefore to assess stability and test-retest reliability of a number of different endocrinological stress markers as well as subjective stress responses after two exposures to the TSST four months apart. We assessed salivary and plasma cortisol profiles, plasma ACTH and noradrenaline profiles, as well as subjective stress ratings in healthy volunteers before, during, and after the TSST at six time-points both at test-day 1 (TSST_1, n = 42) and test-day 2 (TSST_2, n = 34) 4-months later. Half of the participants received the TSST in the early, the other half in the late afternoon. Discontinuous growth models were applied to model three phases of the stress response (preTSST, reactivity, recovery) for each marker. Subsequently, the stability of these phases was analyzed. Stability and test-retest reliability of standard physiological stress markers such as Area-under-the-Curve (AUC_G, AUC_I), Absolute Peak Change, and Relative Peak Change (RPC) were analyzed as well. We did not observe strong test-retest effects in any of the endocrinological measures. In contrast, test-retest effects in subjective stress were characterized by a faster drop directly after the second TSST, whereas the initial increase before the test period was the same for both test-days. Regarding test-retest-reliability, AUC_G was the most reliable measure across all endocrinological and subjective stress markers (range: r = .606 to .858), while AUC_I and RPC (range: r = - .146 to .548) were least reliable. A 4-month interval is a sufficient time interval between two repeated TSST exposures to largely reinstate the physiological stress response, which was also true for the initial psychological stress response. Thus, the TSST is well applicable in longitudinal studies.

Autonomic Nervous System Response to Psychosocial Stress in Anorexia Nervosa: A Cross-Sectional and Controlled Study

To foster understanding in the psychopathology of patients with anorexia nervosa (P_AN) at the psychological and physiological level, standardized experimental studies on reliable biomarkers are needed, especially due to the lack of disorder-specific samples. To this end, the autonomic nervous system (ANS) response to a psychosocial stressor was investigated in n = 19 P_AN (BMI: 18.7 ± 3.3 kg/m²), age, and gender-matched to n = 19 healthy controls (HC; BMI: 24.23 ± 3.0 kg/m²). For this purpose, heart rate (HR) and heart rate variability (HRV) parameters were assessed in a cross-sectional study design under two experimental conditions: (1) rest and (2) stress (Trier Social Stress Test). In addition, psychological indicators of stress were assessed. An 2 × 2 × 8 ANOVA demonstrated similar HR and HRV patterns (except LF-HRV) between P_AN and HC at rest. Under stress, P_AN (vs. HC) demonstrated a blunted HR [condition^*time^*group: F_{(2.91, 104.98)} = 9.326, p = 0.000, η² = 0.206] and an attenuated HRV response (reduced SNS/PNS reactivity). Significant effects of stress appraisal (SA) and BMI on HRV-reactivity were revealed. SA on SDNN = Condition^*time^*SA = F_{(4.12, 140.15)} = 2.676, p = 0.033, η² = 0.073. BMI on LF/HF-Ratio = Condition^*time^*BMI = F_{(3.53, 60.16)} = 3.339, p = 0.019, η² = 0.164. Psychological indices suggested higher levels of chronic and appraised stress in P_AN relative to HC. Additional analyses demonstrated that ED-symptoms are highly correlated with the latter constructs, as well as with psychological burden, but not with weight. Further, it was shown that abnormalities in reactivity persisted despite normalized ANS activity. Overall, we suggested that besides weight recovery, improvement in stress appraisal could be beneficial for cardiac health. In this light, a combination of therapy (e.g., development and activation of coping skills, cognitive reappraisal) and biofeedback training may improve treatment outcomes and regulate stress reactivity.

[Can Stress Interact with SARS-CoV-2? A Narrative Review with a Focus on Stress-Reducing Interventions that may Improve Defence against COVID-19]

OBJECTIVE

The COVID-19 pandemic is on the rise and causes many concerns and fears in the population as well as among medical care givers. This raises the question as to how psychosocial stress associated with the pandemic can be managed, and also if certain forms of stress can contribute to an increase in infections and critical illnesses.

METHODS

Against the background of the current state of research on stress and the immune response, we provide a narrative review of studies addressing the question as to how stress can influence the immune defence against viral diseases.

RESULTS

Excessive stress can compromise the barrier function of the airways and alter neuroendocrine control of immune function, which can create a virus-permissive immune response.

DISCUSSION

Because certain forms of stress can play a role in the successful immune defence against viral respiratory disease, it is important to identify people with high psychosocial stress and to help them manage their stress. Conclusion Psychosocial measures that contribute to improved stress management may have a positive effect on the immune response against viral respiratory infections.

Role of Neuroendocrine, Immune, and Autonomic Nervous System in Anorexia Nervosa-Linked Cardiovascular Diseases

Anorexia nervosa represents a severe mental disorder associated with food avoidance and malnutrition. In patients suffering from anorexia nervosa, cardiovascular complications are the main reason leading to morbidity and mortality. However, the origin and pathological mechanisms leading to higher cardiovascular risk in anorexia nervosa are still unclear. In this aspect, the issue of exact pathological mechanisms as well as sensitive biomarkers for detection of anorexia nervosa-linked cardiovascular risk are discussed. Therefore, this review synthesised recent evidence of dysfunction in multiple neuroendocrine axes and alterations in the immune system that may represent anorexia nervosa-linked pathological mechanisms contributing to complex cardiovascular dysregulation. Further, this review is focused on identification of non-invasive biomarkers for the assessment of increased cardiovascular risk in anorexia nervosa that can be linked to a clinical application. Complex non-invasive assessment of cardiovascular autonomic regulation—cardiac vagal control (heart rate variability), sympathetic vascular activity (blood pressure variability), and cardiovascular reflex control (baroreflex sensitivity)—could represent a promising tool for early diagnosis, personalized therapy, and monitoring of therapeutic interventions in anorexia nervosa particularly at a vulnerable adolescent age.