Robert-Paul Juster

Allostatic load biomarkers of chronic stress and impact on health and cognition

The allostatic load model expands the stress-disease literature by proposing a temporal cascade of multi-systemic physiological dysregulations that contribute to disease trajectories. By incorporating an allostatic load index representing neuroendocrine, immune, metabolic, and cardiovascular system functioning, numerous studies have demonstrated greater prediction of morbidity and mortality over and beyond traditional detection methods employed in biomedical practice. This article reviews theoretical and empirical work using the allostatic load model vis-à-vis the effects of chronic stress on physical and mental health. Specific risk and protective factors associated with increased allostatic load are elucidated and policies for promoting successful aging are proposed.

Chronic stress, cognitive functioning and mental health.

This review aims to discuss the evidence supporting the link between chronic stress, cognitive function and mental health. Over the years, the associations between these concepts have been investigated in different populations. This review summarizes the findings that have emerged from older populations as well as from populations suffering from pathological aging, namely Mild Cognitive Impairment and Alzheimers Disease. Although older adults are an interesting population to study in terms of chronic stress, other stress-related diseases can occur throughout the lifespan. The second section covers some of these stress-related diseases that have recently received a great deal of attention, namely burnout, depression, and post-traumatic stress disorder. Given that chronic stress contributes to the development of certain pathologies by accelerating and/or exacerbating pre-existing vulnerabilities that vary from one individual to the other, the final section summarizes data obtained on potential variables contributing to the association between chronic stress and cognition.

A transdisciplinary perspective of chronic stress in relation to psychopathology throughout life span development.

The allostatic load (AL) model represents an interdisciplinary approach to comprehensively conceptualize and quantify chronic stress in relation to pathologies throughout the life cycle. This article first reviews the AL model, followed by interactions among early adversity, genetics, environmental toxins, as well as distinctions among sex, gender, and sex hormones as integral antecedents of AL. We next explore perspectives on severe mental illness, dementia, and caregiving as unique human models of AL that merit future investigations in the field of developmental psychopathology. A complimenting transdisciplinary perspective is applied throughout, whereby we argue that the AL model goes beyond traditional stress-disease theories toward the advancement of person-centered research and practice that promote not only physical health but also mental health.

A clinical allostatic load index is associated with burnout symptoms and hypocortisolemic profiles in healthy workers

Chronic stress causes stress hormones to strain many biological systems in a process referred to as allostatic load (AL) that is measurable using an index of biomarkers. While the AL framework has been successfully applied in studies of workplace stress, few studies have investigated burnout, a debilitating condition sometimes characterized by blunted stress hormone levels. Using an AL index based on clinical norms, we hypothesized that higher AL indices would be associated with increased chronic stress, burnout symptoms, as well as hypoactive diurnal and reactive stress hormone levels. Fifteen neuroendocrine, immune, metabolic, and cardiovascular biomarkers were collected for 30 healthy participants from various professions and values were transformed into an AL index using clinical norms. Stress reactivity was assessed for salivary cortisol and α-amylase levels in response to the Trier Social Stress Test. Diurnal cortisol was measured at five time points (awakening, 30 min after awakening, 14:00 h, 16:00 h, and before bedtime) over two working days. We also administered questionnaires of chronic stress, burnout, and depression. Our results demonstrate that increased AL is associated with increased chronic stress, burnout symptoms, but not depressive symptoms. The High AL group demonstrated lower morning and stress reactive cortisol levels in comparison to the Low AL group, but no significant effects were detected for salivary α-amylase. These findings provide preliminary support for the utility of a new clinical AL index that is sensitive to physiological recalibrations intermittently observed in burnout research.

Sexual orientation and disclosure in relation to psychiatric symptoms, diurnal cortisol, and allostatic load.

Objectives Lesbian, gay, and bisexual (LGB) individuals—particularly those who have not disclosed their sexual orientation—are believed to experience increased chronic stress in comparison with heterosexuals. This interdisciplinary study assessed whether psychiatric symptoms (self-rated anxiety, depression, and burnout), stress hormone profiles (diurnal cortisol), and physiological dysregulations (allostatic load [AL]) would differ for a) LGBs versus heterosexuals and b) disclosed LGBs versus nondisclosed LGBs. Methods The study included 87 healthy participants (mean [SD] age = 24.6 [0.6] years; LGB n = 46, 43% women; and heterosexual n = 41, 49% women). Diurnal cortisol sampled at five time points was averaged for 2 days. AL indices were based on an algorithm incorporating 21 biomarkers representing neuroendocrine, immune/inflammatory, metabolic, and cardiovascular functioning. Psychological measures were assessed with well-validated questionnaires. Results Between-group results revealed no significant differences in symptoms of anxiety and burnout, nor among diurnal cortisol levels between sexual orientations. By contrast, gay/bisexual men unexpectedly had lower depressive symptoms (p = .003) and AL levels (p = .043) compared with heterosexual men. Within-group results revealed that disclosed LGBs had fewer psychiatric symptoms (p values < 0.01) and lower cortisol levels +30 minutes upon awakening (p = .004) compared with nondisclosed LGBs. Disclosure was not significantly related to AL levels. Conclusions LGBs did not manifest more stress-related problems than did heterosexuals. Life transitions like disclosing to one’s family and friends may be protective against psychopathologies and hyperactive cortisol awakening responses. Our novel findings underline the roles disclosure processes have on positive health and well-being for sexual minorities.

Timing is everything: anticipatory stress dynamics among cortisol and blood pressure reactivity and recovery in healthy adults.

Psychological states of anticipation modulate biological stress responsivity. While researchers generally investigate how subjective distress corresponds to the magnitude of stress reactivity, physiological recovery after acute stressors must also be considered when investigating disease vulnerabilities. This study assessed whether anticipatory stress would correspond to stress reactivity and recovery of salivary cortisol and blood pressure levels in response to a well-validated psychosocial stressor. Thirty participants (63% female; mean ± SEM age 45.4 ± 2.12 years) were exposed to the Trier Social Stress Test (TSST) consisting of a public speech and mental arithmetic. Ten salivary cortisol samples and systolic and diastolic blood pressure recordings were collected at time points spanning 50 min before and up to 50 min after stress exposure. These data were transformed into parameters representing stress reactivity (area under the curve) and stress recovery (percent change). The Primary Appraisal Secondary Appraisal scale assessed anticipatory stress before exposure to the TSST. Our results revealed that increased anticipatory stress predicted increased stress reactivity for cortisol (p = 0.009) but not blood pressure. For stress recovery, increased anticipatory stress predicted greater decrements of cortisol concentration (p = 0.015) and blood pressure (p = 0.039), even when controlling for total systemic “output” by incorporating baseline activity. This efficient shutdown of stress responses would have otherwise been ignored by solely investigating reactive increases. These findings underscore the importance of measuring multiple dynamic parameters such as recovery when investigating physiological stress response patterns as a function of psychosocial factors.

Allostatic load associations to acute, 3-year and 6-year prospective depressive symptoms in healthy older adults

Allostatic load represents the strain that chronic stress exerts on interconnected biological systems. Associated algorithms are related to numerous deleterious physical outcomes in older populations, and yet few studies have assessed associations to mental health outcomes like geriatric depression. Using data from the Douglas Hospital Longitudinal Study of Normal and Pathological Aging, we assessed whether using an allostatic load index derived from seven biomarkers could detect self-rated depressive symptoms in 58 healthy older adults followed longitudinally over a 6-year period. Our results revealed that increased allostatic load was associated with increased depressive symptoms on the same year of assessment. After 3 years, AL was prospectively associated with depressive symptoms, but entering age and sex as covariates attenuated this effect to a trend. Only age emerged as a significant predictor of depressive symptoms over 6 years. These findings suggest that increased AL in older age is only associated with depressive symptomatology acutely. Over longer periods of time, however, the physical and psychological sequelae of advanced age may contribute to increased depressive symptoms via pathways otherwise undetectable using allostatic load indices of sub-clinical physiological dysregulations.

Burnout symptom sub-types and cortisol profiles: What's burning most?

The current study assessed which specific burnout symptoms were most predictive of distinct diurnal cortisol profiles. Participants included 401 day-shift workers employed in a random sampling of 34 Canadian workplaces. The 16-item Maslach Burnout Inventory was used to extract burnout sub-scales that included emotional exhaustion, cynicism, professional inefficacy, as well as a global burnout average. Consenting workers provided five saliva samples a day (awaking, 30 min after awaking, 1,400 h, 1,600 h, and bedtime) repeated three times over the course of a week (Saturday, Tuesday, Thursday) to capture workday and non-workday variations. Multilevel regression models were estimated from cortisol measurements at each occasion within a day at level-1, workers at level-2, and workplaces at level-3. Multilevel regression analyses found that emotional exhaustion and a global burnout showed the strongest and consistent negative associations to cortisol in the afternoon and evening. In a separate analysis using regression coefficients, emotional exhaustion and a global burnout average were associated with low cortisol levels 30 min upon awakening. By contrast, professional inefficacy was associated only with lower bedtime cortisol. No associations were detected for cynicism and sex did not emerge as a moderator in secondary analyses. Our findings are discussed in a theoretical framework postulating different pathophysiological stages of burnout development. Specifically, professional inefficacy may be the earliest warning signal culminating with emotional exhaustion that may dampen diurnal cortisol levels.

Facebook behaviors associated with diurnal cortisol in adolescents: Is befriending stressful?

Facebook(©) is changing the way people interact and socialize. Despite great interest in psychology and sociology, little is known about Facebook behaviors in relation to physiological markers of stress. Given that the brain undergoes important development during adolescence and that glucocorticoids--a major class of stress hormones-are known to modulate its development, it is important to study psychosocial factors that may influence secretion of stress hormones during adolescence. The goal of the present study was to explore the associations between Facebook behaviors (use frequency, network size, self-presentation and peer-interaction) and basal levels of cortisol among adolescent boys and girls. Eighty-eight adolescents (41 boys, 47 girls) aged between 12 and 17 (14.5 ± 1.8) were recruited. Participants provided four cortisol samples per day for two non-consecutive weekdays. Facebook behaviors were assessed in accordance with the existing literature. Well-validated measures of perceived stress, perceived social support, self-esteem, and depressive symptoms were also included. A hierarchical regression showed that after controlling for sex, age, time of awakening, perceived stress, and perceived social support, cortisol systemic output (area under the curve with respect to ground) was positively associated with the number of Facebook friends and negatively associated with Facebook peer-interaction. No associations were found among depressive symptoms, self-esteem, and cortisol. These results provide preliminary evidence that Facebook behaviors are associated with diurnal cortisol concentrations in adolescents.

Sex-specific interaction effects of age, occupational status, and workplace stress on psychiatric symptoms and allostatic load among healthy Montreal workers

Abstract Socio-demographics and workplace stress may affect men and women differently. The aim of this cross-sectional study was to assess sex-specific interactions among age, occupational status, and workplace Demand-Control-Support (D-C-S) factors in relation to psychiatric symptoms and allostatic load levels representing multi-systemic “wear and tear”. It was hypothesized that beyond main effects, D-C-S factors would be moderated by occupational status and age in sex-specific directions predictive of subjective psychiatric symptoms and objective physiological dysregulations. Participants included healthy male (n = 81) and female (n = 118) Montreal workers aged 20 to 64 years (Men: M = 39.4 years, SD = 11.3; Women: M = 42.8 years, SD = 11.38). The Job Content Questionnaire was administered to assess workplace D-C-S factors that included psychological demands, decisional latitude, and social support. Occupational status was coded using the Nam--Powers--Boyd system derived from the Canadian census. Psychiatric symptoms were assessed using the Beck Anxiety Scale and the Beck Depression Inventory II. Sex-specific allostatic load indices were calculated based on fifteen biomarkers. Regression analyses revealed that higher social support was associated with less depressive symptoms in middle aged (p = 0.033) and older men (p = 0.027). Higher occupational status was associated with higher allostatic load levels for men (p = 0.035), while the reverse occurred for women (p = 0.048). Women with lower occupational status but with higher decision latitude had lower allostatic load levels, as did middle-aged (p = 0.031) and older women (p = 0.003) with higher psychological demands. In summary, age and occupational status moderated workplace stress in sex-specific ways that have occupational health implications.