Bibliography / References

Persometrics' services rely on the research reported in the following articles, among other.

2021

Role of dietary fiber in the recovery of the human gut microbiome and its metabolome (2021)

A healthy gut, characterized by so-called "good bacteria" (above all, Lactobacillus and Bifidobacterium), is pivotal to good physical and mental health. Pre- and pro-biotics, which create and feed the good bacteria must actually reach the gut and to be absorbed, and dietary fiber is crucial for this process. This study, together with many others, guide our dietary feedback in our reports, especially the Persometrics Stress Report.

Published in Cell Host Microbe

Melatonin in Wine and Beer: Beneficial Effects (2021)

Researchers from Murcia, Spain review fermentation processes as factors for melatonin production and discuss the theoretical impacts of melatonin on sleep disorders, Multiple Schlerosis, Parkinson's disease and other pathophysiological conditions.

Published in Molecules

Intake and adequacy of the vegan diet. A systematic review of the evidence (2021)

Researchers from School of Medicine at Aristotle University of Thessaloni, WHO Europe, Moscow, department of nutrition at the University of Copenhagen perform a thorough meta analysis scoping 48 studies (from some 2500 identified studies filtered to match preset criteria), showing the pros and cons of a vegan diet. The authors separate deficiencies and actual (negative) health outcome.

Published in Clinical Nutrition

The impact of prior day sleep and physical activity on the cortisol awakening response (2021)

This paper elucidates factors that affect the cortisol awakening response (CAR), notably separating different sleep parameters.

Published in Psychoneuroendocrinology

Base de données suisse des valeurs nutritives/Schweizer Nährwertdatenbank/The Swiss Food Composition Database – V6.3 (23.02.2021)

This database, compiled, published and maintained by the Swiss Federal Food Safety and Veterinary Office has been used to generate ratios of macronutrient lists in our reports. It is a comprehensive database, citing nearly 300 world-wide sources, including whitepapers, laboratory analyses and nutritional information provided from the industry. Access the raw data here, in French or German , or visit their platform.

A Review of foods and food supplements increasing testosterone levels (2021)

From the abstract: the purpose of this review is to summarize the food ingredients that have been suggested in published literature to increase testosterone levels. A review of previously reported animal studies suggested that 5 representative nutritional components, 7 food ingredients, and 25 supplements were associated with testosterone.

Not published in a peer-riewed journal with impressive impact factor, Persometrics treats the authors' conclusions with caution, but the study lends some support to existing hypotheses and has been incorporated in our reports.

Published in the Journal of men's health

The moderating effect of cortisol and dehydroepiandrosterone on the relation between sleep and depression or burnout (2021)

Illucidates the important role of sleep quality in predicting or diagnosing burnout.

Published in Comprehensive Psychoneuroendocrinology

2020

Comparative life cycle assessment of drinking straws in Brazil (2020)

Assessing environmental impact of different products and sources is not only about waste management. It is important to protect our oceans, but a real assessment of environmental impact needs a Life Cycle Assessment. The authors of this study compared different types of straws (Polypropylene plastic, Stainless Steel, Glass, Paper, Bamboo and Wheat stem) and looked at marine litter, climate change, ozone depletion, respiratory inorganics, photochemical ozone formation, acidification, water depletion, land use, resource consumption, eutrophication, energy demand, human toxiticy, and freshwater ecotoxicity. Plastic fares pretty badly, especially if they are not disposed of through appropriate facilities. In this study, environmental impact depends largely on the production methods, and it is still considered to take 100 years to degrade. However, new techniques (adopted by Persometrics) allow for edible straws to be produced and is made from a byproduct material that would otherwise be discarded. We have further tested its validity in salivary hormone testing.

Published in Journal of Cleaner Production

Associations of waking cortisol with DHEA and testosterone across the pubertal transition: Effects of threat-related early life stress (2020)

Early life stress has an impact on how the Hypothalamic Pituitary Adrenal (HPA) axis develops during puberty. The associations between inter-related HPA-dependent hormones are here found to depend on severity of stress before puberty. The study sheds light on the development of the HPA axis and factors influencing Cortisol/DHEA-s relations, important for our Extended Stress Report.

Published in Psychoneuroendocrinology

Mental health before and during the COVID-19 pandemic: a longitudinal probability sample survey of the UK population (2020)

In this secondary analysis of a national, longitudinal cohort study, households that took part in Waves 8 or 9 of the UK Household Longitudinal Study (UKHLS) panel, including all members aged 16 or older in April, 2020, were invited to complete the COVID-19 web survey. Mental health was assessed using the 12-item General Health Questionnaire (GHQ-12). More than 50,000 individuls took part in the study, which showed that clinically significant levels of mental distress rose from pre-COVID times, from 18·9% to 27·3%, one month into UK lockdown. Mean GHQ-12 score also increased over this time, from 11·5 to 12·6 (12·5–12·8) in April, 2020. Perform the General Health Questionnaire (GHQ-12) here.

Published in Lancet Psychiatry

Psychophysiological Stress Markers During Preseason Among Elite Female Soccer Players (2020)

From the abstract: this study investigates modifications and relationship between physiological stress markers after a preseason period between elite footballers. Twenty-four elite soccer players participated in this study. Physical load, mood, morning and evening concentrations of cortisol and testosteronewere all measured. Cortisol is strongly associated with mood. A decrease in testosterone to cortisol ratio of more than 30% indicates incomplete recovery, residual fatigue, and impaired competitive performance. Since the change was non-existent in these players, this suggests that the players had adequate coping with the stresses of training.

Published in the Journal of Strength and Conditioning Research

An Observational Study of Distribution of Symptoms in Patients of Diabetes Mellitus Type2 and Their Correlation with Low Serum Free Testosterone (2020)

Deepak Gupta and collaborators at the Department of Medicine, Mahatma Gandhi Medical College and Hospital Jaipur look athe link between testosterone and type 2 diabetes. Testosterone levels are not only lower in men with type 2 DM, but also that the risk of developing type 2 DM is increased in men with low testosterone levels

Published in: International Journal of Science and Healthcare Research

Cortisol and DHEA-S levels in pregnant women with severe anxiety (2020)

Even though pregnancy has a strong influence on hormone levels, Leff-Gelman and colleagues show that the DHEA-S to cortisol ratio is related to anxiety also in pregnant women in their last trimester

Published in: BMC Psychiatry

Effects of Aerobic Exercise on Cortisol Stress Reactivity in Response to the Trier Social Stress Test in Inpatients with Major Depressive Disorders: A Randomized Controlled Trial (2020)

Swiss researchers from Basel, Solothurn and Kermanshah (Iran) shows interdependence of cortisol reactivitity to a known stress test (TSST) of mental difficulties.

Published in the Journal of Clinical Medecine

2019

Basal Hormones and Biochemical Markers as Predictors of Overtraining Syndrome in Male Athletes: The EROS-BASAL Study (2019)

Explores biochemical markers of overtraining syndrome.

Published in Journal of Athletic Training

Assessment of free testosterone concentration (2019)

Brian G. Keevil and Jo Adaway make a case for Free Testosterone in clinical practise and give details regarding measurement and analysis.

Published in: Journal of Steroid Biochemistry and Molecular Biology

Exercise Mitigates the Loss of Muscle Mass by Attenuating the Activation of Autophagy during Severe Energy Deficit (2019)

Highly collaborative study between Marcos Martin-Rincon and colleaggues from University of Las Palmas de Gran Canaria, as well as researchers from a range of institutions (Spain, Sweden, Norway, and Canada). The researchers investigate fat free weight during energe deficiency.

Published in: Stress

Salience versus magnitude in the measurement of the cortisol awakening response (2019)

Describes Pulsatile ultradian secretion of cortisol, including the cortisol awakening response.

Published in Psychoneuroendocrinology

2018

Physician Burnout, Well-being, and Work Unit Safety Grades in Relationship to Reported Medical Errors (2018)

There has been widespread discussions and responses to this article but the main take-home message remains: physician burnout consistently relates to reduced quality of care, and there are strategies that reduce burnout, targetting not only with the workplace but the individual himself or herself.

Lead author: Daniel S. Tawfik at the Department of Pediatrics, Stanford University School of Medicine.

Published in Mayo Clin Proc.

General Health Questionnaire-12 reliability, factor structure, and external validity among older adults in India (2018)

The purpose of this study is to analyze the internal consistency, factor structure, and external validity of the 12-item General Health Questionnaire (GHQ-12) among older adults in India. Settings and Design: This study analyzes data collected as part of the UNFPA »Building Knowledge Base on Ageing in India (BKPAI)» project. The BKPAI Survey was conducted in 2011 in seven major demographically advanced states of India - Himachal Pradesh, Punjab, West Bengal, Odisha, Maharashtra, Kerala, and Tamil Nadu. Materials and Methods: A community-based representative sample of 9692 respondents aged 60 and above from seven Indian states was employed. The GHQ-12 questionnaire was administered. Statistical Analysis: The Cronbach's alpha was calculated to analyze internal consistency. Factor analysis was applied to explore the factor structure of GHQ-12, and then correlation coefficients were calculated to examine the external validity of the measurement. Results: The Cronbach's alpha of the GHQ-12 is 0.9. Factor analysis reveals two significant components which accounted for 59% of the variance. The correlation between the overall score of GHQ-12 and the subjective well-being inventory (SUBI) is 0.58. Conclusions: The GHQ-12 shows adequate reliability among the older population in India.

Perform the General Health Questionnaire (GHQ-12) yourself now.

Testosterone and Cortisol Responses to Five High-Intensity Functional Training Competition Workouts in Recreationally Active Adults (2018)

Researchers at Kennesaw University and Hofstra University studied changes in cortisol, testosterone and their ratio in function of workout intensity and in function of time points leading up to a competition. Crossfit (R) was used to achieve High-Intensity Functional Training. Findings point to the importance for athletes and coaches of monitoring these hormones (and above all their ratio) when seeking consistency of workouts.

Published in Sports

Authors: Mangine, van Dusseldorp, Feito, Holmes, et al.

Towards utilization of the human genome and microbiome for personalized nutrition (2018)

The study conducted by Eran Segal and colleagues at the Weizman institute suggests that we are asking the wrong question when searching for the right diet and should instead be looking for individualised diets. The researchers used blood sugar spikes as a biomarker for food reactivity and followed some 800 participants longitudinally showing that people differ in their response to food stuffs. An experimental follow-up (diet-intervention) confirmed: the one and same food could have opposite spike patterns for two people. Persometrics finds this a compelling first step to individualised nutrition, and especially promising that the authors incorporate the microbiome in their research, which has been used for our stress reports and has also figured on our social media outlets.

Published in: Current Opinion in Biotechnology

Leptin Levels Are Dependent on Sleep Duration: Relationships with Sympathovagal Balance, Carbohydrate Regulation, Cortisol, and Thyrotropin (2018)

Karine Spiegel, Rachel Leproult, Mireille L’Hermite-Balériaux, Georges Copinschi, Plamen d. Penev, and Eve van Cauter from Universities of Chicago and Brussels (ULB) investigated links between sleep quality (notably how long the participants were allowed to sleep: 4, 8 or 12 hours) and the endocrine system. Sleep restriction decreased leptin, and increased evening cortisol, even when people did not perceive the restriction as stressful. Showing that sleep may have an effect on appetite and in turn obesity. 12 hour slots (no sleep restriction) produced better biomarkers even though participants only slept just over 9 hours in average.

Taken together, we use this information in our guidance of stress reports and also for current development of our sleep reports.

Published in: The Journal of Clinical Endocrinology & Metabolism

Assessment of diurnal melatonin, cortisol, activity, and sleep−wake cycle in patients with and without diabetic retinopathy (2018)

Medical researchers in Denmark showed disturbance in daily melatonin rhythm in patients with diabetic retinopathy

Published in: Sleep Medicine

Authors: Ba-ali, Shakoor; Brøndsted, Adam Elias; Andersen, Henrik Ullits; Sander, Birgit; Jennum, Jørgen, and Lund-andersen, Henrik

Dominant men are faster in decision-making situations and exhibit a distinct neural signal for promptness (2018)

This study was carried out by two of Persometrics's very own (hosted and funded by the Brain Mind Institute at the EPFL). Feel free to contact us for a copy. We showed that dominant males (as measured through questionnaires tapping the wish and propensity to seek to dominate others) are faster than their less dominant counter-parts. The speed advantage was shown in both behavioural tasks (of which there were a variety) and in physiological measurements (EEG). It is believed that this fast reaction time creates an advantage which is what leads men to be treated differently by others, in turn creating the dominant personality trait. We say dominant "men" because we did not study females, not because it does not apply to females. Questionnaire will be available on persometrics.com soon!

Authors: Janir da Cruz*, João Rodrigues*, John C Thoresen*, Vitaly Chicherov, Patrícia Figueiredo, Michael H Herzog, Carmen Sandi

* = ("joint first authors")

Published in: Cerebral Cortex

Stress and Turnover Intents in International Organizations: Social Support and Work Life Balance as Resources (2018)

Giauque and colleagues (from University of Lausanne and University of Geneva) report an extensive study wherein they collected data from questionnaires of some 1700 respondents (more than 7000 were sent out). A take-home message is that perceived stress may mediate the link between job resources and turnouver intention in large international organisations. Changing our perception of stressors gets us a long way.

Published in: International Journal of Human Resource Management

Authors: Giauque, D., Anderfuhren-Biget, S., and Varone, F.

2017

The Influence of Plant- and Animal Based Diets on Circulating Testosterone and Body Composition of Young Male Rats (2017)

Twenty-eight Long-Evans rats followed plant-based or animal-based diets for 12 weeks, with or without exercise. Total circulating testosterone, estradiol, and body composition was then measured. Plant-based diets were associated with lowered fat accumulation, no difference in testosterone, at the same time as providing adequate nutrition for training in rats.

Do psychosocial predictors affect the following days' cortisol awakening response? Expanding the temporal frame with which to explore morning cortisol? (2017)

Explores causation of demands and cortisol awakening response and shows the interaction with affect/emotional states the days prior to the sampling in relation to the CAR.

Morningness/Eveningness, Morning-to-Afternoon Cortisol Ratio, and Antisocial Behavior Problems During Puberty (2017)

Background reading for stress profiling.

Published in: Developmental Psychology

Cortisol Stress Reactivity across Psychiatric Disorders: A Systematic Review and Meta-Analysis (2017)

Frenetic, underchallenged, and worn-out subtypes of burnout are proposed. The authors of this chapter look into prelavence in students too, reporting a study where 509 university students filled out several questionnaires, including adapted versions of the Maslach Burnout Inventory and the Burnout Clinical Subtypes Questionnaire. The study three burnout subtypes was also found in students. and further prposoe differen pathways to burnout.

Published in: Stress

Endocrinological Roles for Testosterone in Resistance Exercise Responses and Adaptations (2017)

A much welcome review article, assessing increases in Testosterone as well as basal levels, and their relationship to adaptations to resistance training. Authors Hooper (Ohio State University and Armstrong State University) and colleagues point out the caution required when drawing inferences between testosterone and adaptations, in large owing to many studies failing to confirm this. Persometrics takes into account in our sports packages where we look at intra-individual as well as inter-individual relationships between exercise, diet, testosterone and performance.

Published in: Sports Medicine

2016

Assessment of the Cortisol Awakening Response: Expert Consensus Guidelines (2016)

This report guided our sampling procedures.

Published in: Psychoneuroendocrinology

Association of Job Strain With Cortisol and Alpha-Amylase Among Shift-Working Health Care Professionals in Laboratory and Field (2016)

Background reading for our stress profiling reports.

Published in: Biological Research for Nursing

Stress Exacerbates Pain in the Everyday Lives of Women with Fibromyalgia Syndrome-The Role of Cortisol and Alpha-Amylase (2016)

Background for stress reports.

Published in: Psychoneuroendocrinology

Absence Management - Annual Survey Report 2016

Absence Management Report in partnership with The CIPD is the professional body for HR and people development. Used by Persometrics as general background reading (see For Business page)

Published in: Cipd

Associations among Sugar Sweetened Beverage Intake, Visceral Fat, and Cortisol Awakening Response in Minority Youth (2016)

Summary

Diet and lifestyle, but also individual differences are important, for combatting the detrimental effects of stress.

Published in: Physiology and Behavior

The cortisol awakening response and cognition across the adult lifespan (2016)

Gilda Ennis, Scott Moffat and Christopher Hertzog performed cognitive testing (episodic memory, working memory and processing speed) and checked for links between cortisol secretion patterns. Further demographics were also included in analyses. We have used this article to help shape procedures and parameters in our stress report.

Published in: Brain and Cognition

The relationship among self-efficacy , perfectionism and academic burnout in medical school students (2016)

A large number of medical students were followed and predictors of burnout tested. Socially prescribed perfectionism (mediated through self-efficacy) was a strong predictor of academic burnout.

Published in: Korean of medical education

Assessment of the cortisol awakening response: Real-time analysis and curvilinear effects of sample timing inaccuracy (2016)

Smyth and her colleagues at Westminster (London) show the importance of correct timing and on self-report time estimates and their impact on the cortisol awakening response. A delay from cortisol secretion to its detection in saliva was also confirmed. Their findings have been helpful to guide the sampling timings of our own reports.

Published in: Psychoneuroendocrinology

Effects of cortisol on hippocampal subfields volumes and memory performance in healthy control subjects and patients with major depressive disorder (2016)

This multidisciplinary study, crossing nursing, mental health, psychiatry and biomedical sciences departments at University of Alberta shows how cortisol concentrations and cortisol patterns are linked with memory performance and brain structure (more specifically volume of subsections of the hippocampus)

Published in: Journal of Affective Disorders

2015

Occupational Segregation and Psychological Gender Differences: How Empathizing and Systemizing Help Explain the Distribution of Men and Women into (Some) Occupations (2015)

Psychometric profiling. This study shows norms for males and females in systematizing and empathizing and is featured in our empathy questionnaire.

Published in: Journal of Research in Personality

Cortisol Covariation within Parents of Young Children: Moderation by Relationship Aggression (2015)

Summary

Background reading for stress profile reports.

Published in: Psychoneuroendocrinology

Effects of 12 Weeks Aerobic Exercise on Plasma Level of TSH and Thyroid Hormones in Sedentary Women (2015)

Summary

Background reading for the stress profile reports.

Published in: European Journal of Sports and Exercise Science

Risk Factors and Prevalence of Burnout Syndrome in the Nursing Profession (2015)

Cross-sectional study by Cañadas-De la Fuente and colleagues on burnout in nurses. Looks at risk-factors and prevalence. Used in our stress reports.

Published in: International Journal of Nursing Studies

The Moderating Role of Personality Traits in the Relationship between Work and Salivary Cortisol: A Cross-Sectional Study of 401 Employees in 34 Canadian Companies (2015)

Summary

Background reading for the stress profile reports.

Published in: BMC Psychology

Hair Cortisol Concentration Is Unaffected by Basic Military Training, but Related to Sociodemographic and Environmental Factors (2015)

Boesch and colleagues at University of Zurich, ETH Zurich and University of Western Ontario, show a link between cortisol in hair and stress, humidity, temperature as well as socioeconomic factors and physiological data such as sweating. Stress through military trainig could not be detected in cortisol concentrations in hair, whereas meteorological data could predict some variance, showing that this technique is experimental and requires stringent control of external variables. Inter-subject factors predicted concentrations as well. Persometrics’s take is that this technique is best used to compare one’s own state across different times.

Published in: Stress

Diurnal cortisol rhythm: Associated with anxiety and depression, or just an indication of lack of energy? (2015)

Harris, Endresen, Tangen, Hansen, Garde, and Eriksen at the universities of Oslo, Bergen, and Copenhagen performed an extensive screening for psychiatric disorders and showed no effect on the cortisol parameters of interest. Limited findings cannot be used to draw conclusions because there were too many confounding factors in this study, no control group, no initial group definition of disorders, and a limited age group (which could explain why there were no signifant results).

Published in: Psychiatry Research

The cortisol awakening response is associated with performance of a serial sequence reaction time task (2015)

Another study confirms the links between cortisol awakening response and neural mechanisms underlying cognitive function and memory.

Published in International Journal of Psychophysiology

Predicting First Onset of Depression in Young Girls: Interaction of Diurnal Cortisol and Negative Life Events (2015)

The researchers report predicting factors of different stress-related illnesses, with a focus on the HPA axis.

Published in Journal of Abnormal Psychology

2010-15

Age-predicted maximal heart rate in healthy subjects: The HUNT Fitness Study (2013)

Researchers from NTNU (Trondheim, Norway) have done an excellent job at improving the traditional "220-age" formula for maximal heart rate. We use their new and more precise calculation in our reports.

Published in: Scandinavian Journal of Medicine and Science in Sports

The Pursuit of Happiness Can Be Lonely (2012)

This research from the university of Colorado has been featured on our social media outlets.

Published in: Emotion

Physical Activity, Daily Cortisol Pattern and the Metabolic Syndrome in Obese Adolescents (2012)

Background reading. This thesis provides good references and insights for the stress reports.

Relationship between the Cortisol Awakening Response and Other Features of the Diurnal Cortisol Rhythm: The Multi-Ethnic Study of Atherosclerosis (2013)

Stress reports

Published in: Psychoneuroendocrinology

Relationship between General Intelligence, Emotional Intelligence, Stress Levels and Stress Reactivity (2012)

Summary

Psychometric and stress profiling. This was also featured on our Emotional Intelligence questionnaire.

Published in: Annals of Neurosciences

Brain Type or Sex Differences? A Structural Equation Model of the Relation between Brain Type, Sex, and Motivation to Learn Science (2012)

This study, which actually looked at gender differences in attitudes to choosing to study science in Switzerland, was used to obtain Swiss norms in our empathy questionnaire.

Published in: International Journal of Science Education

Linking Long-Term Dietary Patterns with Gut Microbial Enterotypes (2012)

This research on gut microbiome composition was used to guide our feedback for lifestyle advice. The study characterized fecal samples and looked at the link between diet and different types of bacteria enterotypes, especially Bacteroides and Prevotella.

Authors: Wu, Gary D; Chen, Jun; Hoffmann, Christian; Bittinger, Kyle; Chen, Ying-yu; Sue, A; Bewtra, Meenakshi; Knights, Dan; Walters, William a; Knight, Rob; Gilroy, Erin; Gupta, Kernika; Baldassano, Robert; Nessel, Lisa; and Li, Hongzhe

Published in: Science

The Size and Burden of Mental Disorders and Other Disorders of the Brain in Europe 2010 (2011)

Published in: European Neuropsychopharmacology

The Microbiome-Gut-Brain Axis: From Bowel to Behavior (2011)

This Viewpoint by Cryan and Mahony at University College Cork Stress gives a breakdown on enteric bacterial fingerprints and the importance of the microbiome in mental and physical wellness.

Published in: Neurogastroenterology and Motility

Biomarkers in Burnout: A Systematic Review (2011)

We value this research from Leiden University medical Center and Leiden University (NL) which shows that basal cortisol cannot predict burnout on large scale on its own, nor can the CAR predict burnout after the fact (which is what is shown in correlational studies). We hold the importance of psychometric data in conjunction with hormonal, and point to the cortisol index which is important immediately before, not after, a burnout.

Authors: Danhof-Ponta, Tineke van Veenb, Frans G. Zitman

Published in: Journal of Psychosomatic Research

What Is More Important for National Well-Being: Money or Autonomy? A Meta-Analysis of Well-Being, Burnout, and Anxiety Across 63 Societies (2011)

Stress reports and psychometric profiling.

Published in: Journal of Personality and Social Psychology

Role Stress and Personal Resources in Nursing: A Cross-Sectional Study of Burnout and Engagement (2011)

Used to shape our stress reports

Published in: International Journal of Nursing Studies

Le Stress Chez Les Personnes Actives Occupées En Suisse - Liens Entre Conditions de Travail, Caractéristiques Personnelles, Bien-Être et Santé (2011)

Background reading.

Caffeinated Coffee Does Not Acutely Affect Energy Intake, Appetite, or Inflammation but Prevents Serum Cortisol Concentrations from Falling in Healthy Men (2011)

Used to shape our Stress reports, notably regarding personalised lifestyle advice.

Published in: Journal of Nutrition

A Clinical Allostatic Load Index Is Associated with Burnout Symptoms and Hypocortisolemic Profiles in Healthy Workers (2011)

Background reading for our stress profiling reports.

Published in: Psychoneuroendocrinology

Changes in the Cortisol Awakening Response (CAR) Following Participation in Mindfulness-Based Stress Reduction in Women Who Completed Treatment for Breast Cancer (2011)

This study conducted by researchers at McGill (Montreal) confirms both the usefulness and complexity of the cortisol awakening response as a biomarker associated with mental illnesses and their treatment. This has been used in our stress reports.

Published in: Complementary Therapies in Clinical Practice

Assessment of Psychotropic-like Properties of a Probiotic Formulation (Lactobacillus Helveticus R0052 and Bifidobacterium Longum R0175) in Rats and Human Subjects (2011)

This research has shaped our stress profile reports, both in questionnaires and in feedback.

Published in: British Journal of Nutrition

Psychological Traits and the Cortisol Awakening Response: Results from the Netherlands Study of Depression and Anxiety (2011)

Summary

Background reading for stress profiling.

Published in: Psychoneuroendocrinology

"Perfectionism and athlete burnout in junior elite athletes: The mediating role of coping tendencies (2010)"

Hill, Hall and Appleton from York St. John university and university of Bedfordshire separate socially prescribed and self-oriented perfectionism in their link with burnout in young athletes. The pathway from perfectionism to burnout differed depending on the sub-facet of perfectionism.

Published in: Anxiety, Stress and Coping

"Stress Bei Schweizer Erwerbstätigen Und Gesundheit (2010)"

This research shows the prevalence of stress in Switzerland.

Published in: SECO

"El burnout académico: Delimitación del síndrome y factores asociados con su aparici?́ (2010)"

Reviews boundaries of burnout against depression and anxiety, especially in the academic field.

Published in: Revista Latinoamericana de Psicologia

The Cortisol Awakening Response in Context (2010)

Angela Clow, Frank Hucklebridge, and Lisa Thorn’s research on diurnal rhythms of cortisol, its Awakening Response and the Suprachiasmatic nucleus. This paper has been used to shape our understanding of the complex cortisol awakening response and in turn to guide our Stress reports.

Published in: International Review of Neurobiology

Cortisol as a Marker for Improvement in Mindfulness-Based Stress Reduction (2010)

Background reading for stress profiling.

Published in: Complementary Therapies in Clinical Practice

Cortisol Awakening Response (CAR)’s Flexibility Leads to Larger and More Consistent Associations with Psychological Factors than CAR Magnitude (2010)

Summary

Background reading for the stress profile reports.

Published in: Psychoneuroendocrinology

2009 and Earlier

Salivary sex hormone measurement in a national, population-based study of older adults (2009)

An important study providing and comparing laboratory results, yielding norms with Persometrics's chosen immunoassay kit.

Published in Journals of Gerontology - Series B Psychological Sciences and Social Sciences

What Stress Does to Your Brain: A Review of Neuroimaging Studies (2009)

This review of neuroimaging stress studies, written by Dedovic, D'Aguiar, and Pruessner, points to the importance of the prefrontal and limbic regions the psychosocial stress, and was used general background reading.

Published in: Canadian Journal of Psychiatry

Cortisol Awakening Response and Psychosocial Factors: A Systematic Review and Meta-Analysis (2009)

This meta-analysis by Chida and Steptoe looks at the link between the Cortisol Awakening Response (CAR) and a range of psychosocial difficulties, including Burnout and fatigue; Depression and anxiety; HPA axis; Job stress; Positive well-being; and Posttraumatic stress disorder (PTSD). They show how predictions of Cortisol Awakening Response (CAR) has been inconclusive in a range of studies. However, their findings point to an important distinction of looking at the different ways of analysing CAR (respect to baseline or to ground, CARi or CARtot). Persometrics always combines Psychometric data when making sense of hormone data.

Published in: Biological Psychology

The Cortisol Awakening Response (CAR): Facts and Future Directions (2009)

Background reading for stress reports. Shaped our sampling procedure.

Published in: International Journal of Psychophysiology

Depression Is Associated with Flatter Cortisol Rhythms in Patients with Coronary Artery Disease (2008)

Research conducted at University College London by Bhattacharyya (UCL), Molloy and Steptoe (National University of Ireland, Galway), relating cortisol to coronary heart disease and depression. Important to our stress reports.

Published in: Journal of Psychosomatic Research

Pattern of Perceived Stress and Anxiety in Pregnancy Predicts Preterm Birth (2008)

Stress reports, psychometric profiling

Published in: Health Psychology

Burned-out (1976)

This seminal article is one where Christina Maslach presents the factorial properties of burnout, proposing the syndrome as affecting those with people-oriented jobs, feeling callouc

Published in: Human Relations

Adult Attachment and Social Support Interact to Reduce Psychological but Not Cortisol Responses to Stress (2008)

This study by Ditzen et al compared men with or without social support and their psychological and physiological response to stress. This research featured on our social media outlets.

Published in: Journal of Psychosomatic Research

The HPA-Axis and Immune Function in Burnout (2007)

Summary

Background reading for the stress profile reports.

Published in: Progress in Brain Research

Coffee, Stress and Cortisol in Nursing Staff (2007)

Background reading for stress reports, especially on personalised lifestyle advice.

Published in: Psychoneuroendocrinology

Contribution to the Construct Validity of the Perceived Stress Questionnaire from a Population-Based Survey (2007)

Psychometric profiling and stress profiling reports.

Published in: Journal of Psychosomatic Research

Several Daily Measurements Are Necessary to Reliably Assess the Cortisol Rise after Awakening: State- and Trait Components (2007)

Guided our cortisol sampling procedure.

Published in: Psychoneuroendocrinology

Optimism, Stress, Life Satisfaction, and Job Burnout in Restaurant Managers (2007)

Psychometric profiling, burnout, stress reports.

Published in: Journal of Psychology: Interdisciplinary and Applied

Enhanced Cortisol Suppression in Response to Dexamethasone Administration in Traumatized Veterans with and without Posttraumatic Stress Disorder (2007)

This study from Utrecht by C. S. De Kloet and colleagues looked at Corticosteroid binding globulin; Cortisol; Dexamethasone suppression test in post traumatic stress disorder. Through salivary testing, differences in total secretion and secretion patterns were found between patients and controls.

Published in: Psychoneuroendocrinology

Clinical Burnout Is Not Reflected in the Cortisol Awakening Response, the Day-Curve or the Response to a Low-Dose Dexamethasone Suppression Test (2006)

Summary

Background reading for the stress profile reports. Hormone data alone is not enough, as these authors show.

Published in: Psychoneuroendocrinology

Peeke and Chrousos Hypercortisolism and Obesity Cortisol (2006)

Summary

Background reading for the stress profile reports.

The "Mini-IPIP" Scales: Tiny-yet-Effective Measures of the Big Five Factors of Personality (2006)

Selection of 20 items of the IPIP database by Donnellan, Oswald and Baird with colleagues at Rice University has been used in our Psychometric profiling. You can perform this test on our website.

Published in: Psychological Assessment

Diurnal Cortisol Decline Is Related to Coronary Calcification: CARDIA Study (2006)

Background reading for stress profiling.

Published in: Psychosomatic Medicine

Salivary Cortisol as a Predictor of Postoperative Fatigue (2005)

Summary

Background reading for stress profile reports.

Published in: Psychosomatic Medicine

Sex Differences in HPA Axis Responses to Stress: A Review (2005)

Background reading for stress profiling.

Published in: Biological Psychology

The Perceived Stress Questionnaire (PSQ) Reconsidered: Validation and Reference Values from Different Clinical and Healthy Adult Samples (2005)

Psychometric profiling.

Published in: Psychosomatic Medicine

Core Self-Evaluations and Job Burnout: The Test of Alternative Models (2005)

This research from University of Texas and Kansas State University, by Best, Stapleton and Downey, relates Burnout to Core self-evaluations, Job satisfaction and perceived organizational constraints and has been important for our stress reports and psychometric profiling. The authors also give information on how to deal with burnout depending on situational and personal constraints.

Published in: Journal of Occupational Health Psychology

Inhibition of Cortisol Production with Metyrapone Prevents Mental Stress-Induced Endothelial Dysfunction and Baroreflex Impairment (2005)

This study by Broadley & Korszun and colleagues was conducted on 36 participants between hospitals at Torquay, London, Birmingham and Cardiff and shows that blocking cortisol production with metyrapone stopped baroreflex sensitivity impairment, thus suggesting that the link between stress and coronary heart disease and sudden cardiac death is mediated by cortisol, the stress hormone.

Published in: Journal of the American College of Cardiology

The China study: the most comprehensive study of nutrition ever conducted and the startling implications for diet, weight loss and long-term health. (2004)

This book covers the extensive nutritional research dubbed The China Study. Many references are used to create personalised lifestyle reports.

Publisher: BenBella Books, Inc.

Brain-Gut Axis and Its Role in the Control of Food Intake (2004)

Stress profiling report.

Published in: J Physiol Pharmacol

Differences in Cortisol Awakening Response on Work Days and Weekends in Women and Men from the Whitehall II Cohort (2004)

Background reading for stress profiling.

Published in: Psychoneuroendocrinology

Salivary Cortisol Response to Awakening in Chronic Fatigue Syndrome (2004)

Summary

Background reading for stress profile reports.

Published in: British Journal of Psychiatry

Acid Base Insulin Resistance (2004)

Stress profile reports. Used for personalised dietary feedback.

Published in: Medical hypotheses

Low Unstimulated Salivary Flow and Subjective Oral Dryness: Association with Medication, Anxiety, Depression, and Stress (2000)

Bergdahl and Bergdahl at the The Arctic University of Norway studied more than 1000 individuals and show links between gender, anxiety, medication and salivary flow. Their research has guided our sampling procedures and data sense-making.

Published in: Psychoneuroendocrinology

Testosterone, cortisol, and mood in a sports team competition (1999)

This fun experiment, which studied hormone behaviour in spectators of a basket match, showed that spectators' testosterone is linked to the performance (points per minute) rather than outcome.

Published in: Hormones and Behaviour

Burnout, Perceived Stress, and Cortisol Responses to Awakening (1999)

Background reading for the stress profile reports.

Published in: Psychosomatic Medicine

Experimental Aging Research: An International Journal Devoted to the Scientific Study of the Aging Process (1992)

Provides some background reading for stress reports.

Published in: Experimental Aging Research: An INternational Journal Devoted to the Scientific Study of the Aging Process

"Achievement questionnaire" (1969; 2003)

Richard Lynn's questionnaire follows a McClelland approach. The questionnaire, which correlates with a variety of personality constructs as well as external criteria, has been used in our Stress Reports.

Published in the British Journal of Psychology

Salivary Cortisol Response during Exposure Treatment in Driving Phobics (2003)

Georg Alpers and colleagues who study Anxiety disorders and Behavior therapy at University of Salzburg looked into cortisol response in people who have a phobia against driving. As was expected, cortisol response to driving exposure followed both subjective ratings and could be predicted by prior knowledge regarding the phobia. This research has been used for our stress reactivity test.

Published in: Psychoneuroendocrinology

Predictors of Fatigue Following the Onset of Infectious Mononucleosis (2003)

Study by Candy, Chalder and colleagues from Department of Immunology the School of Medicine and Institute of Psychiatry in London, looking at cortisol as a risk factor for Chronic fatigue. Results were inconclusive as regards to biological mechanisms responsible for the link between infectious mononucleosis and chronic fatigue from this study: rather, the factors that best predicted the illness changed over time.

Published in: Psychological Medicine

Patterns of Burnout among Mangagers and Professionals: A Comparison of Models (1997)

Cynthia Cordes, Thomas Dougherty and Michael Blum from Binghamton U, University of Missouri and Truman State University, provide data and path analysis looking at other variables that has been useful to shape our Stress reports.

Published in: Journal of Organisational Behaviour

Perceived Stress in a Probability Sample of the United States (1988)

Cohen and Williamson’s data from some 2300 participants provided norms and shaped our stress questionnaires.

Published in: The Social Psychology of Health

Assessment of Fatigue among Working People: A Comparison of Six Questionnaires (2003)

This study by De Vries, Michielsen and Van Heck at Tilburg University guided psychometric testing and was used in stress reports.

Published in: Occupational and Environmental Medicine

Effect of a Hypocaloric Diet, Increased Protein Intake and Resistance Training on Lean Mass Gains and Fat Mass Loss in Overweight Police Officers. (2000)

This experimental study by Demling and DeSanti at Brigham and Women’s Hospital, Boston, compared dietary and exercise interventions on overweight police officers. The outcome points to the importance of macronutrients and individual differences, and has guided our lifestyle advice in stress reports.

Published in: Annals of nutrition & metabolism

Psychoneuroendocrinological contributions to the etiology of depression, posttraumatic stress disorder, and stress-related bodily disorders: the role of the hypothalamus–pituitary– adrenal axis (2001)

Background reading for adrenal stress profiling. Ehlert, Gaab and Heinrichs at the University of Zurich reports how cortisol parameters are linked to different psychiatric disorders

Published in: Biological Psychology

Exploration of the Awakening Cortisol Response in Relation to Diurnal Cortisol Secretory Activity (2001)

Background reading for adrenal stress profiling.

Published in: Life Sciences

Relationship Functioning and Home and Work Demands Predict Individual Differences in Diurnal Cortisol Patterns in Women (2001)

Stress reports.

Published in: Psychoneuroendocrinology

The Potential Role of Hypocortisolism in the Pathophysiology of Stress-Related Bodily Disorders (2000)

Background reading for stress reports

Published in: Psychoneuroendocrinology

Acute effects of different intensities of weight lifting on serum testosterone (1993)

Researchers at Columbia University and Omaha, Nebraska-Lincoln determine effects of moderate versus low weightlifting effects on testosterone output during and after weight lifting.

Published in: Medicine and Science in Sports and Exercise

Experimental Aging Research: An International Journal Devoted to the Scientific Study of the Aging Process (1992)

Provides some background reading for stress reports.

Published in: Experimental Aging Research: An International Journal Devoted to the Scientific Study of the Aging Process

Development of the Stress Response Inventory and Its Application in Clinical Practice. (2001)

This study describes one questionnaire that shaped our psychometric and adrenal profiling.

Published in: Psychosomatic medicine

A Meta-Analysis on the Anxiety- Reducing Effects of Acute and Chronic Exercise. Outcomes and Mechanisms (1991)

Summary

Background reading for the stress profile reports.

Published in: Sports Medicine

“The Core Self-Evaluations Scale: Development of a Measure” (2003)

Psychometric profiling.

Published in: Personnel Psychology

Two Formulas for Computation of the Area under the Curve Represent Measures of Total Hormone Concentration versus Time-Dependent Change (2003)

Background reading for the stress profile reports.

Published in: Psychoneuroendocrinology

"Les Coûts Du Stress En Suisse” (2000)

Summary

Background reading.

Published in: Seco

Distinguishing Optimism From Neuroticism (and Trait Anxiety, Self-Mastery, and Self-Esteem): A Reevaluation of the Life Orientation Test (1994)

Summary

Psychometric profiling.

Published in: Journal of Personality and Social Psychology

Blood hormones as markers of Training stress (1995)

Summary

This extensive research article by Urhausen, Gabriel and Kindermann details overtraining and hormonal factors. Hormones are thought to be the best indicators of overreaching, and adjusting effort in accordance with individual tolerance.

Published in Sports Medicine.

Published in: Journal of Personality and Social Psychology

Diurnal Cortisol Rhythm as a Predictor of Breast Cancer Survival (2000)

Summary

General reading.

Published in: Journal of the National Cancer Institute

Influences of Diet and Nutrition on Clinical Pharmacokinetics (1988)

Review by Karl Anderson (University of Texas) of the many papers showing the impact of diets (in terms of both micronutrients and micronutrients) on drug bioavailability and metabolism. This confirms the importance of food in health; if they do not trump medicinal treatment they do at least interact with how we may respond to it

Published in: Clinical Pharmacokinetics

Meal Stimulation of Cortisol Secretion: A Protein Induced Effect (1981)

Summary

Stress profile reports, individualised lifestyle advice.

Published in: Metabolism

Need for Recovery from Work Related Fatigue and Its Role in the Development and Prediction of Subjective Health Complaints (2003)

Summary

Background reading for stress profiling.

Published in: Occupational and Environmental Medicine

Applied Physiology of Serum Adrenocorticotropic Hormone (1990)

Summary

Background reading for stress profiling.

Published in: European Jouranl of Applied Physiology

Lifestyle, Mental Health Status and Salivary Secretion Rates (2002)

Summary

Background reading for stress profiling.

Published in: Environmental Health and Preventive Medicine

Anxiety and Burnout in the Health Care Work Environment (1998)

Background reading for stress profiling.

Published in: Psychological Reports

Anxiety, Burnout and Coping Styles in General Hospital Staff Exposed to Workplace Aggression: A Cyclical Model of Burnout and Vulnerability to Aggression (2002)

Summary

Background reading for stress profiling.

Published in: Work and Stress