Overview of peer-reviewed research behind the Sapiens diagnostics, including research on allostatic load, hair and saliva stress markers, as well as evidence for interventions.
In a quasi-experimental study, 41 female chronic fatigue syndrome patients underwent the Trier Social Stress Test while self-critical perfectionism, subjective stress, and salivary cortisol responses were measured for 90 minutes. Relationships with illness duration and severity were also examined.
This review examines the literature linking workplace stressors to sympatho-adrenal biomarkers (catecholamines and heart rate variability) and HPA-axis biomarkers (the post-morning cortisol profile), building on prior reviews of work stress and coronary heart disease risk.
This paper synthesizes available evidence on how allostatic load differs by sex, gender, and age, and argues that many studies fail to account for these differences in their analyses. It proposes a model for future allostatic load research that incorporates these factors.
A study of whether urinary cortisol levels and resting heart rate are associated with the risk of fatal and nonfatal cardiovascular events.
A study in 620 cognitively healthy mid-life adults proposing a comprehensive allostatic-load scoring algorithm (ALCS) that incorporates age/sex, quartiles, clinical reference values, and medications, then regressing AL risk categories against brain and white-matter-hyperintensity volumes.
This theoretical paper proposes the energetic model of allostatic load, framing the 'load' of chronic stress as the additional energetic cost of allostasis that leads to hypermetabolism. It links this excess energy expenditure to accelerated physiological decline and biological ageing.
A laboratory study exposed 32 men and 32 women to a psychosocial stressor or a non-stressful control before assessing social cognition with the Reading the Mind in the Eyes Test (RMET) and the Movie for the Assessment of Social Cognition (MASC). It examined whether stress-induced cortisol elevations affect social-cognitive performance and whether effects differ by sex.
A cross-sectional, correlational-predictive study of 131 older adults tested whether social factors (housing conditions, satisfaction with one's home, neighborhood characteristics, social support, family relations, church attendance) predict allostatic load. Allostatic load was computed from ten physiological biomarkers and modeled with multiple linear regression.
A paper on the importance of allostatic load, its constituent biomarkers, and how allostatic load scores are determined, with particular focus on minority and health-disparity populations.
A narrative review of salivary components that could serve as rapid biomarkers for stress, anxiety, and depression and for monitoring pharmacological treatment. It surveys candidates including cortisol, secretory IgA, lysozyme, melatonin, alpha-amylase, chromogranin A, and FGF-2.
An observational study of blood donors that sought psychological and biological correlates of allostatic overload, applying newly introduced clinimetric criteria for allostatic overload. It aimed to map this new definition onto psychological and biological measures in a healthy population.
An 8-day daily-diary study of 181 older men (aged 58-88) estimated emotional reactivity as changes in positive or negative affect in response to daily stressors, then used these estimates to predict 10-year survival with Cox proportional hazards models.
Thirty-seven fasted healthy men were randomized to ingest glucose, protein, fat, or water one hour before the Trier Social Stress Test, with salivary cortisol and blood glucose measured around the stressor. The study tested whether amplification of the cortisol stress response is specific to glucose or a general effect of energy intake.
Sixty-three adolescent survivors of the 2011 Tohoku earthquake provided salivary cortisol three times daily over three days and completed the depression subscale of the General Health Questionnaire. The study assessed whether salivary cortisol could screen for depressive states after a disaster.
A clinical review of the use of salivary cortisol and salivary cortisone to diagnose and monitor conditions of cortisol excess and deficiency, including hydrocortisone replacement. It compares the diagnostic value of salivary cortisone versus salivary cortisol.
A review of how wearable devices measure heart rate variability, comparing HRV-monitoring capabilities across devices and summarizing recent progress in HRV tracking for health monitoring and disease diagnosis. HRV is presented as an indicator of autonomic nervous system function and of physical and mental status.
This review synthesizes research on two neuroendocrine stress systems, the sympathetic-adrenomedullary (epinephrine, norepinephrine) and HPA (cortisol) systems, as indicators of stress and as links between the psychosocial environment and health, focusing on work and gender. It draws on a series of studies of women and men.
In a standardized sleep-laboratory experiment, 112 healthy young men were randomized to one of four one-hour post-awakening light conditions (dim white, bright white, red, or blue) before the Maastricht Acute Stress Test, with cortisol assessed from eight saliva samples. The study tested how light intensity and wavelength affect the cortisol stress response.
A conceptual and methodological paper examining the validity of salivary cortisol as a biomarker of HPA-axis activity in stress research. It reviews the psychological and biological factors that can cause salivary cortisol to diverge from plasma ACTH and cortisol measures, especially under response conditions.
A review of salivary hormones studied as potential biomarkers for the diagnosis, subtyping, and treatment monitoring of depression, motivated by the convenience of non-invasive sampling. It covers cortisol, melatonin, oxytocin, serotonin, DHEA, testosterone, progesterone, and estradiol.
Twenty-four healthy volunteers were randomized to the cold pressor stress test or a warm-water control, then performed a Sternberg working-memory task at three cognitive-load levels, with heart rate and salivary cortisol used to index stress. The study examined acute stress effects on working memory.
A review of recent evidence on cortisol levels in healthy people and in those at risk for or living with depression, bipolar disorder, and psychosis, including patterns during remission. It also considers how antidepressants and antipsychotics affect cortisol secretion.
Volunteers were exposed to a stressor or a control manipulation before completing an acquired-equivalence task probing memory generalization, with the cortisol response to the stressor recorded. The study tested whether acute stress alters the ability to generalize memories.
A review integrating animal and human literature on how psychological stress affects eating, proposing a model of reward-based stress eating centered on cortisol and brain reward circuitry. It examines how chronic HPA-axis activation and glucocorticoid exposure may promote intake of calorie-dense food and visceral obesity.
A mechanisms-in-endocrinology review of how the circadian and ultradian (pulsatile) rhythms of glucocorticoid secretion affect the brain, drawing on observational, in silico, in vitro, and in vivo evidence. It considers implications of glucocorticoid dysrhythmicity for cognition, behavior, and neuropsychiatric disease.
A study building N-of-1 personalized machine-learning models of depressed mood over one month by combining ecological momentary assessments, EEG-synchronized neurocognitive sampling, and wearable lifestyle data, benchmarking seven ML approaches per individual.
A home-based pilot enrolled dementia patients and their family caregivers in an eight-week music intervention, collecting morning and evening salivary cortisol (and morning DHEA-S) over roughly 40 days and analyzing individual trends by linear regression. It explored whether saliva steroids are sensitive biomarkers of intervention-related stress change.
A narrative review of how stress regulates the endocannabinoid system and how those changes shape the stress response, drawing on preclinical and translational human evidence. It synthesizes stress-induced changes in anandamide (AEA), 2-AG, and CB1 receptors across brain regions and their functional consequences for the HPA axis.
A critical narrative review, based on searches of MedLine, Cochrane, Embase, and CINAHL, of how carbohydrate consumption affects physical and mental health, including gut microbiota, stress, and metabolic outcomes. It focuses on the impact of refined and simple carbohydrates on Western diseases.
A narrative review of translational models and biomarkers of stress and resilience in mental health, addressing the development of preclinical and clinical disease models. It discusses the widening gap between animal and human models and the heterogeneity of stress-resilience phenotypes.
An International Society of Psychoneuroendocrinology expert panel synthesized evidence and formulated consensus guidelines for assessing the cortisol awakening response (CAR) from self-collected saliva. It covers sampling accuracy, participant instructions, covariates, protocols, quantification, and reporting.
A representative German community sample of 2527 people aged 14-95 completed a procrastination scale alongside standardized measures of perceived stress, depression, anxiety, fatigue, and life satisfaction. The study examined how procrastination and its correlates vary across the lifespan.
A review of the bidirectional relationship between sleep and the innate immune system, examining how insomnia and sleep loss alter genomic, cellular, and systemic markers of inflammation and how inflammation in turn regulates sleep continuity and structure. It also considers links to inflammaging, cellular ageing, and inflammation-related depressive symptoms.
A review examining the bidirectional links between sleep and inflammation in health and disease. No abstract text was available, so this is based on the title.
A review introducing 'carbotoxicity', the harmful health effects of excessive carbohydrate and refined-sugar intake, drawing on epidemiological, experimental, and clinical trial evidence and outlining the molecular, cellular, and neuroendocrine mechanisms linking carbohydrates to disease and accelerated ageing.
A bench-to-bedside review of how circadian disruption contributes to neurologic, psychiatric, cardiometabolic, immune, and allergic disorders, describing a bidirectional relationship in which disease also disrupts circadian rhythms. It highlights circadian-based interventions such as bright-light therapy, exogenous melatonin, and chronotherapy.
A methodological overview of salivary cortisol assessment in psychoneuroendocrine research, describing its validity as a reflection of unbound blood cortisol and its practical advantages such as stress-free sampling, laboratory independence, and lower cost. It reviews applications including studies in newborns and infants and use in dexamethasone suppression testing.
A double-blind study in 14 habitual coffee drinkers measuring urinary catecholamines and cortisol across a work morning after caffeine (300 mg) versus placebo, with mood and withdrawal symptoms also rated.
A review of the reciprocal 'crosstalk' between sleep and the immune system in health and disease. No abstract text was available, so this is based on the title.
Participants completed the Trier Social Stress Test and were then assigned to give a gift card to someone, receive a gift card, or choose the more attractive card, while mood, heart rate, blood pressure, salivary alpha-amylase, and cortisol were tracked during recovery. The study tested whether prosocial behavior aids physiological and psychological recovery from stress.
A narrative review and expert-consensus paper (endorsed by ESCEO and IOF) synthesizing systematic reviews and meta-analyses on dietary protein intake and bone health in adults, addressing benefits and safety.
A review synthesising 'mega-study' evidence on psychological stress as a risk and prognostic factor for cardiovascular disease, covering childhood adversity, adulthood stress, and the pathophysiological mechanisms (sympathetic activation, lowered arrhythmic threshold, pro-inflammatory and procoagulant responses) that link stress to cardiovascular events.
A cross-sectional study of 275 individuals with or without long COVID combined multidimensional immune phenotyping with machine learning to identify biological features associated with the condition. Circulating immune populations, antibody responses, and hormones including cortisol were compared between groups.
A placebo-controlled crossover experiment in seven healthy men using microdialysis and palmitate turnover under a pancreatic-pituitary clamp to isolate the effect of physiological hypercortisolemia (hydrocortisone infusion) on systemic and regional lipolysis.
A controlled respiration-chamber study in 38 post-obese participants with prediabetes fed in energy balance on a medium- or high-protein diet for 48 hours, measuring how plasma endocannabinoids and related compounds change across the day in relation to energy balance and adiposity.
A review summarising the role of the endogenous cannabinoid system in sleep physiology and the acute and chronic effects of cannabinoid drugs on sleep, drawing on human and rodent research and discussing underlying molecular mechanisms.
A review of stress biomarkers used in behavioural medicine across three stress-sensitive systems, the HPA axis, autonomic nervous system, and immune system, covering cortisol, salivary alpha-amylase, and pro-inflammatory cytokines and their basal and reactive changes, including intervention-induced changes.
This paper reviews the Psychosocial Index, a clinimetric self-rating scale assessing stress, well-being, distress, illness behavior, and quality of life, identifying 20 studies that used it and introducing a revised version and an adolescent/young-adult form. It evaluates the tool's clinimetric properties and clinical applications.
A discussion of the relationship between endocannabinoid signalling and stress resilience, asking whether endocannabinoid deficiency is sufficient to promote vulnerability to stress. No abstract was available, so this is based on the title.
A study developing a Self-Talk Inventory (negative and positive self-talk scales) in 982 undergraduates and examining its factor structure and relationships with symptoms of depression, anxiety, and anger.
A randomised school-based experiment in 53 fourth-graders (aged 9-10) measuring salivary cortisol before and after 12 minutes of high-intensity exercise during a school break versus a movie-watching control condition.
Development of a short 18-item version of the Cognitive Emotion Regulation Questionnaire (CERQ-short), retaining its nine conceptual scales with two items each, and assessment of its psychometric properties against depressive and anxiety symptoms.
A review of how sleep and the circadian system jointly regulate hormones (growth hormone, melatonin, cortisol, leptin, ghrelin) and glucose and lipid metabolism, and how sleep and circadian disturbance such as shift work disrupt these rhythms.
A cross-sectional study of a random sample of 13,779 Swedish workers testing how self-reported job demands, work control, and co-worker social support combine to relate to cardiovascular disease prevalence.
A methodology review of translational rodent and cell-culture models used to study stress and resilience, framing resilience as a dynamic process with four dimensions and summarising the validity, advantages, and limitations of acute, chronic, traumatic, and early-life stress paradigms.
A methodological study assessing the salivary cortisol awakening response (CAR) over six consecutive days, using structural-equation and correlation analyses to separate state from trait components and determine how many sampling days are needed for reliable measurement.
A pilot study in healthy men using two randomized experiments to disentangle which elements of a meditation/cold/breathing training drive sympathetic activation and anti-inflammatory effects, measuring plasma epinephrine and, after an LPS challenge, cytokines.
In a nine-month longitudinal-prospective study of 431 initially healthy adults, cardiorespiratory, muscular, and self-perceived fitness were assessed alongside self-efficacy, with resilience indexed by stressor reactivity (mental-health problems relative to life events and daily hassles). Mediation analyses tested self-efficacy as a mechanism.
A review of exercise snacks (brief, time-efficient bouts of physical activity) as a strategy to increase physical activity and fitness in sedentary populations, examining effects on physical function and exercise capacity and their potential mechanisms. It frames exercise snacks as a way to overcome barriers such as lack of time and equipment.
A multi-site cross-sectional survey of 186 employees measuring perceived stress (Perceived Stress Scale) and self-reported productivity (Health and Work Questionnaire), with comparisons by sex and race.
In the Brown University Medical Student Study, students were followed across a baseline control period and two exam periods to compare weight and metabolic changes between self-identified stress eaters and non-stress-eaters. Nocturnal insulin, cortisol, and total/HDL cholesterol ratios were assessed alongside weight.
A narrative literature review tracing research on stress from its historical roots to current physiological, pathophysiological, and conceptual understanding, and linking these to intervention approaches. It emphasizes a biopsychosocial framework and compares pharmacological and psychological (e.g., CBT and third-wave) therapies.
Two daily-diary studies (N=185 and N=137) testing whether people's implicit beliefs about willpower (limited vs non-limited) interact with daily stress to predict bedtime procrastination.
An analysis of usual micronutrient intakes in 26,282 US adults from the 2005-2016 NHANES, estimating the prevalence of inadequate intake for five immune-support nutrients (vitamins A, C, D, E, and zinc) and the effect of dietary supplements.
A narrative review of original studies, meta-analyses, RCTs, and cohorts from the past five years on how plant and animal dietary protein influence bone health and osteoporosis across patient groups.
A perspective article defining 'exercise snacks', isolated bouts of vigorous exercise of one minute or less performed several times a day, and reviewing early proof-of-concept evidence for their feasibility and cardiometabolic benefits.
A review of the biological mechanisms by which physical fitness, achieved through regular exercise and physical activity, promotes resilience, including psychological and physiological benefits and blunted stress reactivity.
A synopsis of evidence on dietary protein intake above the RDA for optimising health across the lifespan, covering healthy ageing, sarcopenia prevention, appetite regulation, weight and fat loss, and athletic recovery, plus protein quality and timing. It also reviews claimed risks to kidney and bone health.
Analyzed NHANES 2009-2016 data (n=8,721) to estimate the prevalence of optimal cardiometabolic health among US adults using several guideline definitions covering waist circumference, glucose, HbA1c, blood pressure, triglycerides, and HDL cholesterol. Examined how updated cut-points and inclusion of waist circumference changed prevalence estimates.
In 133 healthy adults wearing wrist actigraphy for 7 days, examined how the self-reported timing of zeitgebers (light exposure, eating, physical activity) related to rest-activity rhythm stability and sleep outcomes. Used Spearman correlations and adjusted regression models stratified by chronotype.
Narrative review summarizing how micronutrients (vitamins, minerals) and certain macronutrients (amino acids, cholesterol, fatty acids) modulate immune cell function. Illustrates the effects with examples such as vitamin A, vitamin C and NK cells, vitamin D, selenium, and cholesterol.
Uses 2020 National Health Interview Survey data to describe the prevalence of self-reported sleep difficulties (trouble falling or staying asleep most or every day in the past 30 days) among US adults. Breaks estimates down by sociodemographic and geographic characteristics.
A narrative review based on a selective PubMed/Cochrane search, with attention to guidelines, on the health effects of fructose and free-sugar consumption, particularly for overweight and metabolic syndrome.
Narrative review summarizing evidence on how sleep and circadian disruption (night shift work, abnormal sleep duration, obstructive sleep apnea) affect skeletal health via clock-gene-linked bone turnover. Draws on physiology plus animal and human intervention studies.
Validation study of a brief version of the Resilience Scale for Adults (RSA), a 33-item self-report measure of personal and interpersonal protective resources across six factors, in an Italian non-clinical sample.
A randomized, counter-balanced crossover experiment in 120 healthy men using a Stroop-like task after stress induction versus control, with fMRI to test how individual brain-network configuration moderates the cognitive effects of acute stress.
Narrative review integrating the neuroscience of mindfulness with an emotion-regulation framework. Reviews evidence that dispositional and intentional mindfulness are associated with greater prefrontal, anterior cingulate, and insular cortex activity and reduced amygdala activity during emotionally salient tasks.
Experimental study examining how acute psychosocial stress during memory retrieval affects pattern separation processes on an episodic memory task in young healthy adults.
Narrative review comparing sulforaphane and other phytochemical activators of the transcription factor Nrf2. Discusses sulforaphane's bioavailability and its potency in inducing cytoprotective genes relative to curcumin, silymarin, and resveratrol.
Using representative Swiss cross-sectional and longitudinal survey data with OLS and fixed-effects models, this study estimated how job stressors and resources affect health-related productivity losses from absenteeism and presenteeism, including interactions with personal resources, and estimated the cost of work stress.
Between-subjects experiment testing whether acute psychosocial stress during the post-learning (memory-updating) stage affects false memory formation. Participants studied an event, were exposed to misleading information, then underwent an acute stressor or control task before an immediate and delayed memory test.
Pooled analysis of 13 experiments (N=528) testing the effects of nature versus urban/built environment exposures on executive function using the backwards digit span task. Also examined testing-order effects and whether affective change mediated cognitive effects.
Development and psychometric validation of the Brief Resilience Scale (BRS), a short self-report measure of the ability to bounce back or recover from stress, tested across four samples including student, cardiac, and chronic-pain groups.
Narrative review of the literature on which types of physical exercise best increase bone density in osteoporotic patients, distinguishing weight-bearing aerobic exercise, strength/resistance exercise, multicomponent programs, and whole-body vibration.
Narrative review expanding conceptual models of how social relationships influence stress processes and health-relevant physiology. Focuses on the 'social aggravation' counterpart to social buffering, i.e., how relationships that are sources of stress can produce deleterious physiological effects.
Across four studies with over 400 participants, the authors validated breath counting as a behavioral measure of mindfulness, testing its reliability, correlations with self-reported mindfulness, and links to meta-awareness, mind-wandering, mood, and non-attachment. A randomized online study also compared four weeks of breath-counting training with working-memory training and no training.
This secondary longitudinal analysis of the Adapt Study followed five healthy young men prescribed a sustained increase in water intake for four weeks, with weekly measurement of body-water flux, regulation, distribution, and volume indices. It explored the effects of chronically higher water intake on hydration markers.
An integrative review using the process model of emotion regulation to organize evidence on how disrupted sleep affects emotional experience and regulation, and how this links to psychiatric risk. It highlights conceptual and empirical gaps in distinguishing emotion generation from regulation in sleep research.
Narrative review and critique of definitions, concepts, and theories of psychological resilience. Discusses resilience as involving adversity and positive adaptation, debates trait- versus process-based conceptualizations, and distinguishes resilience from coping.
In a sleep-laboratory experiment, 23 healthy young men underwent polysomnography on a no-light night followed by a night with dim artificial light at night (5 or 10 lux). Sleep architecture was compared between the two conditions.
Psychometric validation of the Mindful Attention Awareness Scale (MAAS) in 810 undergraduates using exploratory and confirmatory factor analysis and item response theory. Proposes and evaluates a 5-item short version.
A review of how chronic stress dysregulates the hypothalamic-pituitary-adrenal axis and sex-hormone (particularly androgen) systems, contributing to abdominal obesity, with attention to sex differences in stress adaptation and the control of feeding.
Narrative review of strategies to reduce oxidative stress at three levels: lowering exposure to oxidizing pollutants, increasing endogenous/exogenous antioxidants, and stabilizing mitochondrial energy production. Discusses nutritional and psychosocial approaches and the inconclusive evidence for synthetic antioxidant supplements.
Narrative review examining definitions and traditions of resilience research specifically in the context of chronic stress in adults, which is particularly harmful to health. Develops a taxonomy of resilience resources to guide future research.
Theoretical review bridging animal and human evidence to propose how stress-related neuromodulators drive dynamic shifts in large-scale brain network balance during and after acute stress. Argues acute stress reallocates neural resources toward a salience network at the expense of an executive control network.
Perspective/hypothesis communication proposing that exercise-induced hormesis underlies many benefits of physical activity for healthy aging. Suggests antioxidant adaptation, PGC-1alpha-driven mitochondrial biogenesis, and eccentric-contraction-induced muscle inflammation as key redox-sensitive pathways.
Educational review of hydration status assessment, water balance, and the impact of hydration on cognitive performance. Summarizes evidence linking body-water deficits to impaired attention, critical thinking, and memory.
A review of how dietary factors influence health and longevity through hormesis, focusing on how caloric restriction, intermittent fasting, and certain phytochemicals (e.g., sulforaphane, curcumin, resveratrol) induce adaptive cellular stress responses that increase stress resistance.
Experimental study in 48 non-clinical participants selected for high versus low emotional avoidance, who underwent inhalations of 20% CO2-enriched air while instructed either to suppress or to observe their emotional response. Assessed anxiety, affective distress, and physiological arousal.
A handbook chapter reviewing research on stress in organizations, covering concepts of stressors and stress reactions, theories of organizational stress, and evidence from observational, longitudinal, laboratory, and field studies. It reviews resources such as job control, social support, and coping as moderators and surveys stress-intervention approaches.
