Trier Social Stress Test Protocol Research Articles

Comparing a Fitbit Wearable to an Electrocardiogram Gold Standard as a Measure of Heart Rate Under Psychological Stress: A Validation Study

Wearable devices collect physiological and behavioral data that have the potential to identify individuals at risk of declining mental health and well-being. Past research has mainly focused on assessing the accuracy and the agreement of heart rate (HR) measurement of wearables under different physical exercise conditions. However, the capacity of wearables to sense physiological changes, assessed by increasing HR, caused by a stressful event has not been thoroughly studied. This study followed 3 objectives: (1) to test the ability of a wearable device (Fitbit Versa 2) to sense an increase in HR upon induction of psychological stress in the laboratory; (2) to assess the accuracy of the wearable device to capture short-term HR variations caused by psychological stress compared to a gold-standard electrocardiogram (ECG) measure (Biopac); and (3) to quantify the degree of agreement between the wearable device and the gold-standard ECG measure across different experimental conditions. Participants underwent the Trier Social Stress Test protocol, which consists of an oral phase, an arithmetic stress phase, an anticipation phase, and 2 relaxation phases (at the beginning and the end). During the stress protocol, the participants wore a Fitbit Versa 2 and were also connected to a Biopac. A mixed-effect modeling approach was used (1) to assess the effect of experimental conditions on HR, (2) to estimate several metrics of accuracy, and (3) to assess the agreement: the Bland-Altman limits of agreement (LoA), the concordance correlation coefficient, the coverage probability, the total deviation index, and the coefficient of an individual agreement. Mean absolute error and mean absolute percent error were calculated as accuracy indices. A total of 34 university students were recruited for this study (64% of participants were female with a mean age of 26.8 years, SD 8.3). Overall, the results showed significant HR variations across experimental phases. Post hoc tests revealed significant pairwise differences for all phases. Accuracy analyses revealed acceptable accuracy according to the analyzed metrics of accuracy for the Fitbit Versa 2 to capture the short-term variations in psychological stress levels. However, poor indices of agreement between the Fitbit Versa 2 and the Biopac were found. Overall, the results support the use of the Fitbit Versa 2 to capture short-term stress variations. The Fitbit device showed acceptable levels of accuracy but poor agreement with an ECG gold standard. Greater inaccuracy and smaller agreement were found for stressful experimental conditions that induced a higher HR. Fitbit devices can be used in research to measure HR variations caused by stress, although they cannot replace an ECG instrument when precision is of utmost importance.

An Evaluation of Speech-Based Recognition of Emotional and Physiological Markers of Stress

Life in modern societies is fast-paced and full of stress-inducing demands. The development of stress monitoring methods is a growing area of research due to the personal and economic advantages that timely detection provides. Studies have shown that speech-based features can be utilised to robustly predict several physiological markers of stress, including emotional state, continuous heart rate, and the stress hormone, cortisol. In this contribution, we extend previous works by the authors, utilising three German language corpora including more than 100 subjects undergoing a Trier Social Stress Test protocol. We present cross-corpus and transfer learning results which explore the efficacy of the speech signal to predict three physiological markers of stress—sequentially measured saliva-based cortisol, continuous heart rate as beats per minute (BPM), and continuous respiration. For this, we extract several features from audio as well as video and apply various machine learning architectures, including a temporal context-based Long Short-Term Memory Recurrent Neural Network (LSTM-RNN). For the task of predicting cortisol levels from speech, deep learning improves on results obtained by conventional support vector regression—yielding a Spearman correlation coefficient (ρ) of 0.770 and 0.698 for cortisol measurements taken 10 and 20 min after the stress period for the two corpora applicable—showing that audio features alone are sufficient for predicting cortisol, with audiovisual fusion to an extent improving such results. We also obtain a Root Mean Square Error (RMSE) of 38 and 22 BPM for continuous heart rate prediction on the two corpora where this information is available, and a normalised RMSE (NRMSE) of 0.120 for respiration prediction (−10: 10). Both of these continuous physiological signals show to be highly effective markers of stress (based on cortisol grouping analysis), both when available as ground truth and when predicted using speech. This contribution opens up new avenues for future exploration of these signals as proxies for stress in naturalistic settings.

Efectos psicofisiológicos de la respiración diafragmática y la estimulación térmica sobre la actividad autonómica del estrés agudo

Estudios recientes han evaluado los efectos psicofisiológicos del estrés agudo, la respiración diafragmática (RD) y la estimulación térmica cutánea. El paradigma Trier Social Stress Test (TSST) se ha utilizado como prueba de laboratorio para inducir estrés; sin embargo, no cuenta con una fase de reversiva activa de los efectos que induce. La presente investigación tuvo dos objetivos: 1) evaluar el efecto de la RD sobre la actividad autonómica simpática y la respuesta inflamatoria después del TSST para revertir sus efectos cardiovasculares; y 2) explorar el efecto de la estimulación térmica para inhibir la actividad autonómica durante y después del TSST. Se utilizó un diseño cuasi-experimental de medidas repetidas para cada objetivo. Participaron 22 estudiantes universitarios, normotensos y clínicamente sanos divididos en dos sub-grupos de 11 participantes cada uno. Se aplicaron medidas psicométricas de distrés psicológico (PHQ-4, PC-PTSD), se registró su presión arterial, su tasa cardiaca, su temperatura nasal y en el dedo de la mano izquierda, así como una muestra salival de interleucina 6 (citoquina asociada a procesos inflamatorios sensible a la alteración física y afectiva del organismo). Aunque se igualaron las características sociodemográficas, debido al horario de registro de la presión arteiral en cada grupo y el periodo escolar de cada participante, las muestras no fueron comparables entre sí por lo que los datos se analizaron por separado para cada objetivo: al primer grupo se le administró el protocolo de TSST y después se les instruyó un ejercicio de RD; mientras que el segundo grupo sostuvo con las manos una compresa térmica a una temperatura aproximada de 41°C durante y después del TSST. Los resultados sugirieron que la RD disminuyó la actividad autonómica, pero no la inflamatoria; mientras que el grupo con estimulación térmica inhibió la actividad autonómica durante y después del TSST. Estos hallazgos se discuten en el contexto de la Teoría Polivagal como estrategias psicológicas para disminuir e inhibir los efectos psicofisiológicos del estrés agudo.

Influence of Regular Physical Activity and Fitness on Stress Reactivity as Measured with the Trier Social Stress Test Protocol: A Systematic Review.

Psychosocial stress is associated with multiple health complaints. Research to date suggests that regular physical activity (PA) and higher cardiorespiratory fitness may reduce stress reactivity and therefore contribute to a reduction of stress-related risk factors. While previous reviews have not differentiated between stressors, we focus on psychosocial stress elicited with the Trier Social Stress Test (TSST). Our objective was to examine the effect of regular PA and cardiorespiratory fitness on stress reactivity, with a particular focus on the TSST. The TSST is the laboratory task most widely used to induce socio-evaluative stress and elicits stronger stress reactions than most other cognitive stressor tasks. A systematic search within various databases was performed in January 2018. The following outcomes were considered: cortisol, heart rate, psychological stress reactivity, and potential moderators (age, sex, exercise intensity, assessment mode, and psychological constructs). In total, 14 eligible studies were identified. Cortisol and heart rate reactivity were attenuated by higher PA or better fitness in seven of twelve studies and four of nine studies, respectively. Two of four studies reported smaller increases in anxiety and smaller decreases in calmness in physically active/fitter participants. Three of four studies found that higher PA/fitness was associated with more favorable mood in response to the TSST. About half of the studies suggested that higher PA/fitness levels were associated with an attenuated response to psychosocial stress. Currently, most evidence is based on cross-sectional analyses. Therefore, a great need for further studies with longitudinal or experimental designs exists.

Sex differences in salivary cortisol reactivity to the Trier Social Stress Test (TSST): A meta-analysis

Some, but not all studies using the Trier Social Stress Test (TSST) have demonstrated evidence in support of sex differences in salivary cortisol. The aim of the current meta-analysis is to examine sex differences in salivary cortisol following exposure to the TSST. We further explored the effects of modifications to the TSST protocol and procedural variations as potential moderators. We searched articles published from January, 1993 to February, 2016 in MedLine, PsychINFO, and ProQuest Theses and Dissertations. This meta-analysis is based on 34 studies, with a total sample size of 1350 individuals (640 women and 710 men). Using a random effects model, we found significant heterogeneity in salivary cortisol output across sexes, such that men were observed to have higher cortisol values at peak and recovery following the TSST compared to women. Modifications to the sampling trajectory of cortisol (i.e., duration of acclimation, peak sampling time, and duration of recovery) significantly moderated the heterogeneity across both sexes. Further, there are observed sex differences at various time points of the reactive cortisol following the TSST. Lastly, current results suggest that these sex differences can be, at least in part, attributed to variations in methodological considerations across studies. Future research could advance this line of inquiry by using other methods of analyses (e.g., area under the curve; AUC), in order to better understand the effects of methodological variations and their implications for research design.

Validation of a low intrusiveness heart rate sensor for stress assessment

Heart rate variability (HRV) analysis has been used as a quantitative marker of the autonomous nervous system activity to measure mental stress. Wearable sensors have been emerging as a solution to collect HRV data for stress assessment in a real context, however such studies raise additional requirements. The wearable system must be minimally obtrusive to allow the subjects to perform their tasks without interference, and inconspicuous to avoid the anxiety associated with wearing medical devices in public. The purpose of this study was to quantify the accuracy trade-off in the use of a chest band heart rate sensor that is less intrusive and less costly than a wearable electrocardiogram (ECG). The HRV metrics extracted from a chest band heart rate monitor, Zephyr HxMTM (ZphTM), were compared with those extracted from an ECG certified medical device, Vital JacketTM (VJTM). The two systems were worn simultaneously under laboratory conditions by a population of 14 young and healthy subjects, aged 20 to 26 years, under the stress induced by the Trier Social Stress Test (TSST) procedure. The results showed a mean difference between RR intervals of 9 ms; a root-mean square error (RMSE) of less than 8% and a Pearson’s correlation higher than 0.946, considering all TSST phases. In the HRV analysis, the average of all normal intervals (AVNN) showed errors less than 2% between the two systems with a correlation higher than 0.99 for all TSST phases. We thus conclude that the used chest band sensor represents an alternative to the current wearable medical devices to monitor RR intervals, and could be used for mental stress monitoring similar to the TSST protocol.

Patterns of cortisol and alpha-amylase reactivity to psychosocial stress in maltreated women

BackgroundChildhood maltreatment can trigger enduring changes in major stress response systems, particularly in the context of major depressive disorder (MDD). However, the relative impact of maltreatment versus MDD on hypothalamic-pituitary-adrenal axis and sympathetic-adrenal-medullary system stress reactivity is not well understood. MethodThis study examined salivary cortisol and alpha-amylase responses to the Trier Social Stress Test (TSST) in 26 maltreated (15 with current MDD) and 26 non-maltreated (17 with current MDD) women. ResultsMaltreated women showed greater anticipatory cortisol reactivity during the TSST protocol compared to non-maltreated women. Maltreated women also showed rapid deceleration in cortisol levels. Whereas non-maltreated women showed initial declines in alpha-amylase levels but rapidly increasing alpha-amylase levels during the TSST protocol, maltreated women did not exhibit changes in alpha-amylase levels during the TSST protocol. Contrary to expectation, MDD did not impact cortisol or alpha-amylase responses. LimitationsThe present study is limited by retrospective report of childhood maltreatment, cross-sectional design, and modest sample sizes. ConclusionsThese findings suggest that childhood maltreatment plays a greater role driving alterations in cortisol and alpha-amylase stress reactivity than MDD. Understanding the biological embedding of maltreatment is critical for elucidating mechanisms linking these experiences to risk for negative mental and physical health outcomes.

Pro-inflammatory cytokines and soluble receptors in response to acute psychosocial stress: Differential reactivity in bipolar disorder

Mounting evidence suggests a chronic pro-inflammatory state in individuals with bipolar disorder (BD). Stress exposure is known to exacerbate several inflammatory conditions as well as psychiatric disorders. Here, we analyzed plasma levels of pro-inflammatory cytokines and their soluble receptors to realistic acute psychosocial stress challenge in BD. Thirteen euthymic type 1 BD patients and 15 matched controls underwent the Trier Social Stress Test protocol (TSST). Blood samples were collected before and after TSST and plasma cytokines interleukin IL-2, IL-6, IL-33, and tumor necrosis factor alpha (TNF-α) were measured. In addition TNF-α soluble receptors TNFR1 and TNFR2, and IL-33 soluble receptor sST2 were assessed. Increased IL-33 and reduced sST2 levels were observed in BD subjects as compared to controls, independently of stress exposure. Following TSST, there were higher levels of IL-2 and reduced levels of sTNFR1 in both groups. However, the magnitude change for both cytokines was found higher in controls than BD subjects. Our data suggest that BD patients have differential stress reactivity as compared to controls, possibly related to an immunologic imbalance and failure of regulatory mechanisms.

Effects of an experimental social stressor on resources loss, negative affect, and coping strategies

This experimental study, grounded in Hobfoll's conservation of resources (COR) theory, assessed the effects of manipulating a social stressor on loss of psychological resources, negative affect, and coping strategies. Israeli student volunteers were randomly allocated to one of two conditions: (1) social stressor (n = 66) and (2.) nonstressor (n = 59). The social stressor, aimed at reducing participant's personal resources, was experimentally induced via the Trier Social Stress Test protocol. The protocol consisted of a mock job interview administered under evaluative conditions, followed by performing a difficult arithmetic calculation task. The nonstressor condition involved a neutral interaction with an experimenter, followed by performing a relatively easy mental calculation task. Consistent with our hypotheses, the social stressor, compared to the nonstressor condition, resulted in statistically significant lower mean levels of psychological resources, higher levels of negative affect, and increased emotion-oriented and avoidance-oriented coping. Furthermore, under the social stressor condition, compared with the nonstressor condition, negative affect was more strongly related to loss of psychological resources and various coping strategies. Overall, the data provide experimental support for key tenets of COR theory

Differential neuroendocrine and immune responses to acute psychosocial stress in women with type 1 bipolar disorder

Bipolar disorder (BD) has been associated with immune imbalance, including lymphocyte activation and increased pro-inflammatory cytokines. Immune activation is part of stress response, and psychosocial stress has been implicated in the pathogenesis of psychiatric disorders. Here, we investigated the neuroendocrine and immune responses to acute psychosocial stress challenge in BD. Thirteen euthymic participants with type 1 BD and 15 healthy controls underwent the Trier Social Stress Test protocol (TSST). Blood samples were collected before and after TSST. Lymphocytes were isolated and stimulated in vitro to assess lymphocyte activation profile, lymphocyte sensitivity to dexamethasone, mitogen-activated protein kinase (MAPK) and nuclear factor kappa B (NF-κB) signaling by flow cytometry. Heart rate and salivary cortisol levels were monitored across the task. BD participants exhibited blunted stress responses as shown by reduced heart rate and salivary cortisol levels in comparison to healthy controls. BD was also associated with reduction in the percentage of regulatory T cells, but with expansion of activated T cells. When compared to controls, patients showed increased lymphocyte MAPK p-ERK and p-NF-κB signaling after the stress challenge, but exhibited a relative lymphocyte resistance to dexamethasone. In conclusion, stress-related neuroendocrine responses are blunted, associated with increased immune activation and lower sensitivity to glucocorticoids in BD. An inability in reducing NF-κB and MAPK signaling following TSST could be underlying the immune imbalance observed in BD.

スピーチによる唾液アミラーゼの変動と達成感の関連

Recent studies indicated that salivary alpha-amylase (sAA) is useful not only as a surrogate biological marker for sympathetic nervous activity, but also as a non-invasive index of psychological stress. Some psychophysiological studies have revealed significant increases of aAA during acute stress induces by experimental stressors such as the Trier Social Stress Test (TSST), which were comparable to other endocrinological indices such as salivary cortisol. However, association between change of sAA and performance of public speech within the TSST remain unclear. Thus, in the present study, we recruited 10 participants (mean age = 20.60, SD = 0.80 yrs) to investigate the associations between transition of sAA and performance of speech. SAA and pulsatile heart rate were measured three times before, and three times after the social stress challenge. SAA was measured with a portable sAA biosensor (Salivary amylase monitor; NIPRO, Japan). The Profile of Mood State (POMS) test and Visual Analogue Scale (VAS) were administered to participants after the TSST protocol. An ANOVA revealed a significant increase of sAA after the task. However, no significant change of pulsatile heart rate was observed. Neither a correlation between sAA and VAS nor a correlation between POMS and VAS was observed. These results suggest that sAA induced by the TSST would be a reliable biomarker of acute stress. However, associations between sAA response and performance of public speech during the TSST still remain under question to be further explored.

Elevated salivary C-reactive protein in maltreated children

Childhood maltreatment can trigger enduring changes in major stress response systems, particularly in the context of major depressive disorder (MDD). However, the relative impact of maltreatment versus MDD on hypothalamic-pituitary-adrenal axis and sympathetic-adrenal-medullary system stress reactivity is not well understood.This study examined salivary cortisol and alpha-amylase responses to the Trier Social Stress Test (TSST) in 26 maltreated (15 with current MDD) and 26 non-maltreated (17 with current MDD) women.Maltreated women showed greater anticipatory cortisol reactivity during the TSST protocol compared to non-maltreated women. Maltreated women also showed rapid deceleration in cortisol levels. Whereas non-maltreated women showed initial declines in alpha-amylase levels but rapidly increasing alpha-amylase levels during the TSST protocol, maltreated women did not exhibit changes in alpha-amylase levels during the TSST protocol. Contrary to expectation, MDD did not impact cortisol or alpha-amylase responses.The present study is limited by retrospective report of childhood maltreatment, cross-sectional design, and modest sample sizes.These findings suggest that childhood maltreatment plays a greater role driving alterations in cortisol and alpha-amylase stress reactivity than MDD. Understanding the biological embedding of maltreatment is critical for elucidating mechanisms linking these experiences to risk for negative mental and physical health outcomes.