Area Under The Curve Increase Research Articles

Hypocortisolemic reactivity to acute social stress among lonely young women

ABSTRACT We examined biopsychosocial stress of acute social pain in relation to chronic loneliness. Hypotheses: 1) Cyberball exclusion (vs. inclusion) would be associated with lower cortisol reactivity to a speech task, and 2) loneliness would moderate the relationship between social exclusion and cortisol reactivity to a speech task, such that higher loneliness would be linked to lower cortisol. Participants (n = 31, women, aged 18–25, 51.6% non-Hispanic white) were randomized to be excluded or included in a game of Cyberball, then completed a speech task. Salivary cortisol was measured at baseline, pre-speech, post-speech, and 15 minutes post-speech. Cortisol reactivity was calculated using area under the curve-increase (AUCi). ANOVA revealed a non-significant, meaningful effect of Cyberball exclusion on cortisol AUCi (p=.103, η p 2 =.10), accounting for contraceptive use. Moderation analysis revealed among women with high loneliness, women in the exclusion condition had significantly lower cortisol reactivity than women in the inclusion condition (p=.001). For women with low and medium loneliness, there were no significant differences by Cyberball condition. In sum, lonely young women who are excluded may have hypocortisolemic responses to social stress. Results are consistent with literature suggesting that chronic stress is linked to lower cortisol responses, which is linked to negative physical health outcomes.

Extraversion modulates cortisol responses to acute social stress in chronic major depression

BackgroundChronic Major Depressive Disorder (CMDD) is a common, disabling illness that is often complicated by high reactivity to social stress. To further elucidate the nature of this reactivity, the current study evaluated whether the personality dimensions of neuroticism and extraversion influenced cortisol responses to a social challenge in CMDD patients vs. controls. MethodsFifty participants with CMDD and 58 healthy controls completed the Trier Social Stress Test (TSST) using a standard protocol. Neuroticism and extraversion were measured using the Revised NEO Personality Inventory. Hierarchical linear regressions assessed associations between independent variables neuroticism and extraversion and dependent variable cortisol area-under-the-curve increase (AUCi) in response to the TSST in the two study groups. ResultsThe extraversion-by-group interaction was a significant predictor of cortisol AUCi, while no significant findings related to neuroticism were found. Simple slopes analysis revealed a significant negative association between extraversion and AUCi in the CMDD group, but not in healthy controls. Post-hoc analysis of the raw cortisol data over time found that CMDD participants with higher extraversion scores had significantly higher pre-challenge cortisol levels than did other study participants, however this did not explain or confound the AUCi results. ConclusionsIn participants with CMDD but not in controls, higher levels of extraversion were associated with higher pre-challenge cortisol levels and decreased cortisol reactivity during the TSST, however these two findings were statistically independent. These findings underline the importance of considering personality factors when studying stress biology in CMDD patients. Extraversion may prove to be an important intermediate target for both research and clinical work in this complex, heterogenous and often treatment-resistant population.

Minor Immediate Effects of a Dog on Children's Reading Performance and Physiology.

Literacy is a key factor in occupational success and social integration. However, an increasing number of children lack appropriate reading skills. There is growing evidence that dogs have positive effects on reading performance. We investigated the short-term effects of dogs on reading performance in 36 third-graders and monitored physiological parameters [heart rate (HR), heart rate variability (HRV), and salivary cortisol] as well as behavioral variables. Each child took part in two test sessions at the presence of a tutor, in one of which a dog and its handler were present. To assess reading performance two reading tests were used: two subtests of the standardized “Ein Leseverständnistest für Erst- bis Sechstklässler”, where the children have to carry out time-limited reading tasks, to assess sentence and text comprehension, and repeated reading (RR), where the children have to read the same text twice, to assess reading speed and short-term improvement. Although the dog had no effect on reading performance scores, within the first test session the children improved from the first to the second run of RR when a dog was present but not without dog. The behavior of the children indicated a calming effect of the dog in the first test session with less nervous movements and the children being less talkative. We found no impact of the dog on HR and HRV. However, the excitement about the dog in combination with the unknown situation in the first test session was reflected in a higher difference in the mean HR difference between the two test sessions for the children, who in the first test session had a dog present, compared to the children, who had the dog in the second test session. In the second test session, the children were more aroused with a dog present than with no dog present, as indicated by the area under the curve increase (AUCi) of salivary cortisol values. We conclude that the presence of a dog had a minor short-term positive effect on the children’s motivation and reading performance. More substantial effects could probably be achieved with repeated sessions.

High reactivity of the cortisol awakening response predicts positive treatment outcome in heterogeneous depressed patients completing an alternate milieu inpatient program

ObjectiveDelineating clinically meaningful subgroups within heterogeneous depressed populations is a major challenge. As outlined in the Research Domain Criteria Strategy, biomarkers may help to empirically classify such patients. Following this basic strategy, the current pilot study examined whether the cortisol awakening response (CAR) following admission to hospital predicts treatment response in heterogeneous depressed patients completing a 4-week alternate milieu inpatient program. MethodsThe Alternate Inpatient Milieu program at the Centre for Addiction and Mental Health is composed of both individual-based and group-based programming designed to promote a recovery-oriented, collaborative treatment environment. The current sample consisted of 25 consecutive patients with various forms of complex/chronic depression who completed the full program. Saliva samples were collected at 0, 30 and 60 min after awakening on 2 consecutive days following admission. Linear regressions controlling for baseline depression scores were used to assess whether the CAR AUCg (area under the curve ground) and/or AUCi (area under the curve increase) at admission predicted the change in depression scores from admission to discharge based on the Quick Inventory of Depressive Symptoms scale. ResultsThe CAR AUCi, but not the CAR AUCg, at admission significantly predicted treatment response over the 4-week hospital stay. In these naturalistic patients with major depressive disorder, high CAR reactivity as assessed using the AUCi was associated with a better treatment response (t=2.20; df=2,24; P=.039). The CAR was easy to implement and well accepted by patients and staff. ConclusionThis pilot study suggests that CAR reactivity at admission may help to identify a subgroup of depressed patients most likely to respond clinically to a 4-week alternate milieu inpatient program.

Salivary alpha amylase diurnal pattern and stress response are associated with body mass index in low-income preschool-aged children

Physiological stress responses are proposed as a pathway through which stress can "get under the skin" and lead to health problems, specifically obesity. We tested associations of salivary alpha amylase (sAA) diurnal patterns and stress responses with body mass index (BMI) in young, low-income children (51% male; 54% non-Hispanic white). Diurnal saliva samples were collected three times per day across three days for 269 children (M age 50.8 months, SD 6.3). Individual sAA intercept and slope values were calculated using random effect models to represent morning sAA levels and rate of sAA change across the day. A subset of children (n=195; M age 56.6 months, SD 6.9) participated in a lab-based behavioral stress protocol. Area under the curve increase (AUCI) across four timepoints was calculated to represent increase in sAA output during stress elicitation. Children were weighed and height measured and BMI z-score was calculated. Linear regression was used to evaluate associations of sAA intercept, sAA slope, and sAA AUCI with BMI z-score, controlling for child age, sex, and race/ethnicity; maternal weight status; and family income-to-needs ratio. Diurnal and stress-response sAA patterns were related to child adiposity: for each 1-standard deviation unit (SDU) decrease in morning sAA level, the child's BMI z-score increased by 0.11 (SE 0.05) SDU's (p<.04); for each 1-SDU increase in sAA slope across the day, the child's BMI z-score increased by 0.12 (SE 0.05) SDU's (p<.03); and for each 1-SDU decrease in sAA AUCI during the stress elicitation, the child's BMI z-score increased by 0.14 (SE 0.06) SDU's (p<.03). Blunted stress responses and atypical diurnal patterns of sAA have been found following exposure to chronic life stressors such as poverty. Findings suggest that associations of stress, sAA, and elevated body mass index may develop very early in the lifespan.

Daily Life Stress and the Cortisol Awakening Response: Testing the Anticipation Hypothesis

The cortisol awakening response (CAR) is a distinct facet of the circadian cortisol rhythm associated with various health conditions and risk factors. It has repeatedly been suggested that the CAR could be a result of the anticipated demands of the upcoming day (stress anticipation) and could support coping with daily life stress. In a sample of 23 healthy participants CARs were assessed on two consecutive days by measures of salivary cortisol upon awakening (S1) and 30 and 45 minutes later, which were aggregated to the area under the curve increase (AUCI). Stress anticipation was assessed immediately after awakening. On the same days, daily life stress and distress were assessed six times per day based on a quasi-randomized design using handheld computers. Associations were tested by day using regression analysis and standard multilevel/mixed effects models for longitudinal data. The CAR AUCI moderated the effect of daily life stress on distress; higher CAR increases were associated with attenuated distress responses to daily life stress on both days (day 1: p = .039; day 2: p = .004) adjusted for age, gender, sleep quality, time of awakening and oral contraceptive use. Lagged-effects and redundancy models showed that this effect was not due to prior-day CAR increases but specific for same day CARs. On day 2, associations between daily life stress and distress were stronger when individuals showed a higher S1 cortisol level, but this effect was similar for S1 on day 1, and the day 2 effect of S1 became non-significant when S1 on day 1 was controlled. No associations were found between stress anticipation and CARs. Findings indicate that the CAR increase is associated with successful coping with same-day daily life stress.

Endogenous cortisol is associated with functional connectivity between the amygdala and medial prefrontal cortex

Whether glucocorticoids mediate medial prefrontal cortex (mPFC) regulation of the amygdala in humans remains unclear. In the current study we investigated whether cortisol levels under relatively stress-free circumstances are related to amygdala resting-state functional connectivity with the mPFC. Resting-state fMRI data were acquired from 20 healthy male participants. Salivary cortisol was sampled at multiple times throughout the experiment. The cortisol area under the curve increase (AUCi) was calculated as a measure of cortisol dynamics. Next, seed based correlations were employed on the resting-state fMRI data to reveal regions of amygdala functional connectivity related to variations in cortisol AUCi. The resulting statistical maps were corrected for multiple comparisons using cluster based thresholding (Z>2.3, p<.05). Two regions in the mPFC showed decreasing negative functional connectivity with the amygdala when a lesser decrease in cortisol AUCi was observed: the perigenual anterior cingulate cortex and medial frontal pole (BA10). Although we initially showed a relation with cortisol AUCi, it seemed that the baseline cortisol levels were actually driving this effect: higher baseline cortisol levels related to stronger negative functional connectivity with the mPFC. Endogenous cortisol levels may modulate amygdala functional connectivity with specific regions in the mPFC, even under relatively stress-free circumstances. Our results corroborate previous findings from both animal and human studies, suggesting cortisol-mediated regulation of the amygdala by the mPFC. We propose that through this feedback mechanism the stress response might be adjusted, pointing to the putative role of cortisol in modulating stress- and, more generally, emotional responses.

The Effect of a Real Dog, Toy Dog and Friendly Person on Insecurely Attached Children During a Stressful Task: An Exploratory Study

ABSTRACTThe regulation of stress by an attachment figure is a key feature of attachment relationships. Previous research suggests that in some cases animal companionship may be regarded as an attachment relationship. This may be particularly important for persons with an insecure or disorganized attachment pattern who may find it more difficult than securely attached individuals to accept social support from humans. In our study, we investigated whether 31 boys (aged 7–12 years) with insecure/disorganized attachment would profit more from the presence of a dog (n = 11) than of a friendly human (n = 11) or a toy dog (n = 9) as support during a socially stressful situation (Trier Social Stress Test for Children, TSST-C). Stress levels were assessed via salivary cortisol recorded five times before, during, and after the TSST-C. The behavior of the children was coded from video recordings. Self-reported stress levels did not significantly differ between the groups before and after the TSST-C. Salivary cortisol, however, was significantly lower in the real dog condition than in the other two conditions (Kruskal-Wallis H test on area under the curve increase (AUCi): χ2 = 15.17, df = 2, p = 0.001). Also, the more the children stroked the dog, the less pronounced was their stress reaction (rs = −0.818, p = 0.002). Our data suggest an important role of physical contact in the stress reducing effect. We conclude that the children investigated profited more from interacting with a friendly dog than with either a human or a toy dog in a stressful situation. We discuss the relevance of our findings for animal-assisted interventions.

BDNF Val66Met polymorphism is associated with HPA axis reactivity to psychological stress characterized by genotype and gender interactions

A key protein in maintaining neuronal integrity throughout the life span is brain-derived neurotrophic factor (BDNF). The BDNF gene is characterized by a functional polymorphism, which has been associated with stress-related disorders such as anxiety-related syndromes and depression, prompting us to examine individual responses by Genotype and Sex to a standardized social stress paradigm. Gender differences in BDNFxstress responses were posited because estrogen induces synthesis of BDNF in several brain regions. 97 university students (51 females and 46 males) participated in a social stress procedure (Trier Social Stress Test, TSST). Indices of stress were derived from repeated measurement of cortisol, blood pressure, and heart rate during the TSST. All subjects were genotyped for the Val66Met polymorphism. Tests of within-subject effects showed a significant three-way interaction (SPSS GLM repeated measures: Time (eight levels)xBDNF (val/val, val/met)xSex: p=0.0002), which reflects gender differences in the pattern of cortisol rise and decline during the social challenge. In male subjects, val/val homozygotes showed a greater rise in salivary cortisol than val/met heterozygotes. In female subjects, there was a trend for the opposite response, which is significant when area under the curve increase (AUCi) was calculated for the val/val homozygotes to show the lowest rise. Overall, the same pattern of results was observed for blood pressure and heart rate. These results indicate that a common, functionally significant polymorphism in the BDNF gene modulates HPA axis reactivity and regulation during the TSST differently in men and women. Findings may be related to gender differences in reactivity and vulnerability to social stress.

The relationship between alexithymia and salivary cortisol levels in somatoform disorders

The purpose of this study was to investigate cortisol levels as a function of the hypothalamic–pituitary–adrenal axis (HPA) in relation to alexithymia in patients with somatoform disorders (SFD). Diurnal salivary cortisol was sampled in 32 patients with SFD who also underwent a psychiatric examination and filled in questionnaires (Toronto Alexithymia Scale, TAS scale; Screening for Somatoform Symptoms, SOMS scale; Hamilton Depression Scale, HAMD). The mean TAS total score in the sample was 55.6±9.6, 32% of patients being classified as alexithymic on the basis of their TAS scores. Depression scores were moderate (HAMD=13.2, Beck Depression Inventory, BDI=16.5). The patients’ alexithymia scores (TAS scale “Difficulty identifying feelings”) correlated significantly positively with their somatization scale scores (Symptom Checklist-90 Revised, SCL-90-R); r=0.3438 (P<0.05) and their scores on the Global Severity Index (GSI) on the SCL-90-R; r=0.781 (P<0.01). Regression analysis was performed with cortisol variables as the dependent variables. Cortisol levels [measured by the area under the curve–ground (AUC-G), area under the curve–increase (AUC-I) and morning cortisol (MCS)] were best predicted in a multiple linear regression model by lower depressive scores (HAMD) and more psychopathological symptoms (SCL-90-R). No significant correlations were found between the patients’ alexithymia scores (TAS) and cortisol levels. The healthy control group (n=25) demonstrated significantly higher cortisol levels than did the patients with SFD; in both tests P<0.001 for AUC-G and AUC-I. However, the two groups did not differ in terms of their mean morning cortisol levels (P>0.05). The results suggest that pre-existing hypocortisolism might possibly be associated with SFD.