Salivary cortisol in ambulatory assessment--some dos, some don'ts, and some open questions

Stress and strategic decision-making in the beauty contest game

Often, economic decisions do not only depend on one's own preferences, but also on the choices of others and therefore require strategizing (i.e., thinking about what others might think). In experimental economics, this has been modeled by the beauty contest game. Another typical feature of economic decisions is that they are often carried out under stress. Therefore, in the present study, we aimed to examine the influence of stress on decision-making in the beauty contest game. Participants were randomly assigned to either the Trier Social Stress Test for Groups (TSST-G) or a placebo version of the TSST-G (control condition). Then, participants played four rounds of a standard beauty contest game. As a biomarker of stress, salivary cortisol was measured. As predicted, participants under stress chose higher numbers in the beauty contest game than non-stressed participants, indicating less strategizing. This effect was mediated by the stress-induced increase in cortisol.

Salivary mental stress proteins

Of the major diagnostic specimen types, saliva is one of the most easily collected. Many studies have focused on the evaluation of salivary proteins secreted by healthy people and patients with various diseases during responses to acute mental stress. In particular, such studies have focused on cortisol, α-amylase, chromogranin A (CgA), and immunoglobulin A (IgA) as salivary stress markers. Each of these salivary stress markers has its own strengths and weaknesses as well as data gaps related to many factors including collection technique. In this review, we summarize the critical knowledge of the positive and negative attributes and data gaps pertaining to each salivary stress marker.

Longitudinal measurement of cortisol in association with mental health and experience of domestic violence and abuse: study protocol

BACKGROUND

Domestic violence and abuse is threatening behavior, violence/abuse used by one person to control the other within an intimate or family-type relationship. Women experience more severe physical and sexual domestic violence and abuse and more mental health consequences than men. The current study aims at exploring of the role of hypothalamic-pituitary-adrenocortical axis activity in abuse impact on women's mental health.

STUDY OBJECTIVES

1) To evaluate diurnal cortisol slope, cortisol awakening response, and the mean cortisol concentration in women with a current or recent experience of abuse; 2) To estimate whether cortisol secretion is associated with type, severity, duration and cessation of abuse; 3) To investigate whether cortisol acts as mediator between abuse and mental health condition; 4) To examine whether there is any distinction in cortisol levels between those women exposed to both childhood abuse and domestic violence and abuse and those experienced only the latter. 4) To explore whether cortisol secretion differs between women living in refuge and those still living in the community.

METHODS/DESIGN

To meet study objectives 128 women will be recruited in a domestic violence agency and local communities. Baseline and 3-month follow-up measures will be taken over 6 months after recruitment. Each assessment will include: (1) standardized self-administered questionnaires to evaluate socio-demographics, experience of violence and abuse, mental and physical health; (2) weight and height measurement; (3) self-completion of wakening, post-wakening and evening saliva samples. Saliva will be analysed for cortisol and cortisone using Ultra performance liquid chromatography-tandem mass spectrometry. We will compare diurnal cortisol parameters between non-abused controls and abuse survivors with and without mental health conditions. First following descriptive statistics for all the cortisol and mental health outcomes, relationships between them will be investigated using appropriate regression models. Second, these techniques will be used to investigate the extent to which cortisol measures act as potential mediators between type, severity, duration of abuse and mental disorders.

DISCUSSION

Results of the study will increase our understanding of the pathophysiological mechanisms of abuse-related mental health disorders in women and inform researchers and practitioners on the possibility of using salivary cortisol as a biological marker for prognosis, diagnosis, and treatment evaluation among abuse survivors.

TRIAL REGISTRATION

ClinicalTrials.gov registration NCT01632553.

Reflections on the interaction of psychogenic stress systems in humans: the stress coherence/compensation model

Although stress simultaneously affects and causes changes in central nervous system systems together with the sympathetic nervous system and the hypothalamus-pituitary-adrenal axis, this interaction and its behavioral consequences are rarely assessed. The current paper first describes the different systems involved in the perception and processing of stressful stimuli on an anatomical and functional level, and the available measures to assess changes in these systems. It then explores, based on theoretical and empirical grounds, the interaction of the systems. This is followed by a review of previous stress models, and how these attempted to integrate the interaction of these systems. Then, it complements previous models by suggesting a complementary regulation of the stress systems, and discusses potential behavioral consequences. Finally, based on the three-system approach to assess stress it is argued that psychological measures, together with physiological and endocrine measures are indispensable. However, the lack of consensus on how to best assess the central and sympathetic nervous system components of stress make it more difficult to include measures of all systems routinely in future stress studies. Thus, the paper closes by giving some recommendations on how to include a minimum of feasible stress measures for all systems involved in stress processing and regulation.

Major depression in young girls is related to altered cortisol awakening response

BACKGROUND

There is evidence that clinical depression is associated with elevated basal cortisol levels in adult patients.

OBJECTIVE

The present investigation tries to find out, whether this relationship also holds true in adolescents with major depression.

METHODS

For 131 female subjects (63 MDD, 68 controls) the cortisol awakening response (CAR) was measured at 0, 30, 45, and 60 min after awakening. All subjects provided saliva cortisol.

RESULTS

A significantly higher CAR was found in patients. The global mean difference was due to differences 60 and 45 min after awakening.

LIMITATIONS

A causal interpretation of the data is restricted, because of its cross-sectional nature. The effect size of the mean differences is rather small.

CONCLUSION

The observed HPA hyperactivity may be a cause as well as a consequence of depression in childhood.

Cortisol responses to naturalistic and laboratory stress in student teachers: comparison with a non-stress control day

Ambulatory assessments of hypothalamus-pituitary-adrenal axis responses to acute natural stressors yield evidence on stress regulation with high ecological validity. Sampling of salivary cortisol is a standard technique in this field. In 21 healthy student teachers, we assessed cortisol responses to a demonstration lesson. On a control day, sampling was repeated at analogous times. Additionally, the cortisol awakening response (CAR) was assessed on both days. Participants were also exposed to a laboratory stressor, the Trier Social Stress Test, and rated their individual levels of chronic work stress. In pre-to-post-stress assessment, cortisol levels declined after the lesson. However, post-stress cortisol levels were significantly higher compared with those on the control day. Also, the Trier Social Stress Test yielded higher cortisol responses when using the control day as reference baseline. Associations between the CAR and chronic stress measures were observed solely on the control day. There were no significant associations between cortisol responses to the natural and laboratory stressors. Our results indicate that a control day might be an important complement in laboratory but especially in ambulatory stress research. Furthermore, associations between chronic stress measures and the CAR might be obscured by acute stress exposure. Finally, responses to the laboratory stressor do not seem to mirror natural stress responses.

Influences of early shift work on the diurnal cortisol rhythm, mood and sleep: within-subject variation in male airline pilots

We aimed to investigate how early and late work shifts influenced the diurnal cortisol rhythm using a within-subjects study design. Participants were 30 healthy male non-smoking pilots, mean age 39.4, employed by a short-haul airline. The standard rotating shift pattern consisted of 5 early shifts (starting before 0600 h), followed by 3 rest days, 5 late shifts (starting after 1200 h) and 4 rest days. Pilots sampled saliva and completed subjective mood ratings in a logbook 6 times over the day on two consecutive early shift days, two late days and two rest days. Sampling was scheduled at waking, waking+30 m, waking+2.5 h, waking+8 h, waking+12 h and bedtime. Waking time, sleep duration, sleep quality and working hours were also recorded. Cortisol responses were analysed with repeated measures analysis of variance with shift condition (early, late, rest) and sample time (1-6) as within-subject factors. Early shifts were associated with a higher cortisol increase in response to awakening (CAR(i)), a greater total cortisol output over the day (AUC(G)) and a slower rate of decline over the day than late shifts or rest days. Early shifts were also associated with shorter sleep duration but co-varying for sleep duration did not alter the effects of shift on the cortisol rhythm. Both types of work shift were associated with more stress, tiredness and lower happiness than rest days, but statistical adjustment for mood ratings did not alter the findings. Early shift days were associated with significantly higher levels of circulating cortisol during waking hours than late shifts or rest days.