Showing papers by "Clemens Kirschbaum published in 2011"
TL;DR: The TSST-G provides a novel, effective, and economical protocol for experimental paradigms requiring simultaneous stress induction in multiple participants and induced significant increases in cortisol, heart rate, and psychological stress responses.
301 citations
TL;DR: Evidence is provided for a stress-induced time-dependent decrease of cognitive flexibility that might be related to changes in cortisol levels, which paralleled the time course of the hypothalamus–pituitary–adrenal (HPA) stress response.
Abstract: Dynamically adjusting the right amount of goal shielding to varying situational demands is associated with the flexibility of cognitive control, typically linked with pFC functioning. Although stress hormones are found to also bind to prefrontal receptors, the link between stress and cognitive control remains elusive. Based on that, we aimed at investigating effects of acute psychosocial stress on dynamic control adjustments. Forty-eight healthy volunteers were exposed to either a well-established stress induction protocol (the Trier Social Stress Test, TSST) or a standardized control situation before a selective attention (Simon) task involving response conflicts. The individual physiological stress response was monitored by analyzing levels of free cortisol and α-amylase activity in saliva samples showing that the TSST reliably induced an increase of endogenous stress hormone levels. Acute stress did not inevitably impair cognitive functioning, however, as stressed participants showed tonically increased goal shielding (to reduce interference) at the expense of decreased cognitive flexibility. Importantly, as a novel finding in humans, stress effects on cognitive functions were not present immediately after the stress experience but developed gradually over time and, therefore, paralleled the time course of the hypothalamus-pituitary-adrenal (HPA) stress response. In addition, the total increase of individual cortisol levels reflecting HPA activity, but not the total changes in α-amylase activity associated with sympathetic activity, was reversely related to the amount of cognitive flexibility in the final block of testing. Our study provides evidence for a stress-induced time-dependent decrease of cognitive flexibility that might be related to changes in cortisol levels.
195 citations
TL;DR: The hair cortisol findings tentatively suggest that under naturalistic conditions GAD is associated with hypocortisolism, and demonstrates the important qualities of cortisol measurement in hair as an ecologically valid, retrospective index of long-term cortisol secretion and as a marker for psychiatric disorders associated with hypo- or hypercortisolistan.
Abstract: article i nfo Previous research examining hypothalamic-pituitary-adrenal (HPA) axis activity in generalised anxiety disorder (GAD) has suggested a general hypercortisolism. These studies have mostly relied on salivary, plasma or urinary assessments, reflecting cortisol secretion over short time periods. The current study utilised the novel method of cortisol assessment in hair to obtain a retrospective index of cortisol secretion over a prolonged period of time. Hair cortisol levels were determined in 15 GAD patients and in 15 age- and gender- matched controls. In addition, participants collected six saliva samples (on awakening, +30 min, 12:00, 16:00, 20:00 h and at bedtime) on two consecutive weekdays for the assessment of the diurnal cortisol profile. Results revealed significantly lower (50-60%) cortisol levels in the first and second 3-cm hair segments of GAD patients compared to those of controls. No significant between-group differences were seen in diurnal cortisol profiles. The hair cortisol findings tentatively suggest that under naturalistic conditions GAD is associated with hypocortisolism. If corroborated by future research, this demonstrates the important qualities of cortisol measurement in hair as an ecologically valid, retrospective index of long-term cortisol secretion and as a marker for psychiatric disorders associated with hypo- or hypercortisolism.
191 citations
TL;DR: The current hair cortisol findings suggest that PTSD in severely traumatized individuals who continue to live under stressful conditions might be associated with general hypercortisolism.
169 citations
TL;DR: Results indicate that an fMRI experiment may elicit subjective and neuroendocrine stress reactions that can influence functional activation patterns and lead to impaired data quality and premature termination of scans.
118 citations
TL;DR: The data support the idea that work breaks during complex laparoscopic surgery can reduce psychological stress and preserve performance without prolongation of the operation time compared with the traditional work scheme.
Abstract: Background
Intermittent work breaks are common in fields with high workload but not yet for surgeons during operations. We evaluated the effects of intraoperative breaks during complex laparoscopic surgery (5 min every half hour) on the surgeon.
110 citations
TL;DR: Variation in the FKBP5 gene is associated with both cortisol(AUC) and the likelihood of depressive symptoms and a genome wide association study of cortisol (GWAS) findings suggest this.
103 citations
TL;DR: There was a significant interaction of 5-HTTLPR genotype and SLEs, but this interaction was only significant in younger adults and only when the measured SLES had occurred during the first 5 years of life, suggesting that both age and the specific type of SLE has a role in whether a significant gene–environment interaction is observed.
89 citations
TL;DR: Evidence is provided that in depressed compared to healthy women, cortisol's effects on hippocampal function are altered, and in both depressed men and women, glucocorticoids' effects on emotional memory formation and hippocampalfunction are related.
54 citations
TL;DR: It is suggested that morning serum cortisol is not a causal factor in the development of dementia, and there was no relation between serum levels of cortisol and the risk of developing dementia or Alzheimer's disease.
Abstract: Higher levels of cortisol have been observed in persons with cognitive decline and dementia. It is unknown whether these higher levels are a cause or a consequence of disease. We investigated whether morning levels of serum cortisol were associated with cognitive function, cognitive decline, and the risk of dementia and Alzheimer's disease in the Rotterdam Study, a large prospective population based cohort study. Cortisol levels were assessed in fasting blood serum in 3341 participants, who were free of dementia at baseline (1997-1999). Cognitive function was assessed with a dedicated neuropsychological test battery at baseline and at follow-up examination (2002-2004). In addition, the cohort was continuously monitored for incident dementia until January 1, 2007. After a mean follow-up of 7.1 years, 243 participants had developed dementia, of whom 210 were diagnosed with Alzheimer's disease. Morning serum levels of cortisol were neither related to cognitive function at baseline, nor to annual cognitive decline. There was no relation between serum levels of cortisol and the risk of developing dementia or Alzheimer's disease. These results suggest that that morning serum cortisol is not a causal factor in the development of dementia.
53 citations
TL;DR: Regression analyses revealed a significant effect of HTR1A genotype with the G allele being associated with a less pronounced stress response and an inverse relationship between past stressful life events and cortisol release but no gene × environment interaction was detected.
TL;DR: Overall, pack-years was related to morning cortisol rise, but this was accounted for by current smokers, and time since quitting was positively associated with a greater decline in daytime cortisol indicating that the effects of smoking remit is short-term rather than long-term.
TL;DR: This study provides the first evidence for an impairment of the ability to flexibly implement task goals in chronically sleep‐deprived new parents and, thus, for a link between chronic sleep curtailment and executive functions.
Abstract: SUMMARY Chronic sleep curtailment is a major concern for health in Western societies. Yet, research on potential consequences of long-term sleep curtailment on cognitive functions is still scarce. The present study investigated the link between chronic sleep limitation and executive functions that enable adaptation to changing environmental demands, i.e. the ability to flexibly implement task goals. To address the effects of chronic sleep restriction under real-life conditions, we considered a sample of adults who often suffer from reduced sleep durations over many months. One-hundred and six new parents (infants age: 6–18 months) were assigned to a sleep-curtailed group ( h of nighttime sleep) and a non-sleep-curtailed group (‡ 7 h of nighttime sleep), respectively, based on their self-reported average nighttime sleep duration over the preceding 6 months. The ability to implement task goals was addressed applying a taskswitching paradigm in which participants randomly switched between two tasks. While the two groups did not differ with regard to overall performance level, number of nighttime awakenings, naps during the day, daytime sleepiness, mood, chronic stress level and subjectively perceived cognitive capability, sleep-curtailed new parents showed higher costs for switching between tasks compared with repeating a task than non-sleep-curtailed new parents. This finding on the group level was further substantiated by a negative correlation between nighttime sleep duration and switch costs. With this study, we provide the first evidence for an impairment of the ability to flexibly implement task goals in chronically sleep-deprived new parents and, thus, for a link between chronic sleep curtailment and executive functions.
TL;DR: Older adult carriers of COMT variants, which result in lower enzyme activity and therefore probably enhanced dopamine signaling, showed stronger startle activity, and the results point to a potential influence of SLC6A3 on startle magnitude.
Abstract: The dopamine transporter (DAT) and the enzyme catechol-O-methyltransferase (COMT) both terminate synaptic dopamine action. Here, we investigated the influence of two polymorphisms in the respective genes: DAT1 (SLC6A3) VNTR and COMT val158met (rs4680). Startle magnitudes to intense noise bursts as measured with the eye blink response were recorded during the presentation of pictures of three valence conditions (unpleasant, pleasant and neutral) and during baseline without additional pictorial stimulation in a sample of healthy older adults (N = 94). There was a significant Bonferroni corrected main effect of COMT genotype on the overall startle responses, with met/met homozygotes showing the highest and participants with the val/val genotype showing the lowest startle response, while participants with the val/met genotype displayed intermediate reactions. There was also a DAT1 VNTR main effect, which, after Bonferroni correction, still showed a tendency toward significance with carriers of at least one 9-repeat (R) allele showing smaller overall startle responses compared to 10R/10R homozygotes. Thus, older adult carriers of COMT variants, which result in lower enzyme activity and therefore probably enhanced dopamine signaling, showed stronger startle activity. Although the functional significance of DAT1 VNTR is less defined, our results point to a potential influence of SLC6A3 on startle magnitude.
TL;DR: A higher total output of sAA was found in individuals not using AD or being hypertensive, and especially pronounced in hypertensive individuals not use AD, which indicates a difference between normotensive and hypertensives and an association of AD with characteristics of diurnal amylase.
TL;DR: While stretching improved fatigue and physical functioning, yoga buffered changes associated with XRT in terms of fatigue, QOL and benefit finding, resulted in steeper cortisol slopes, and increased HRV, suggesting that the benefits of yoga are due to more than simple stretching, social support or other indirect effects.
Abstract: 9009 Background: Radiotherapy (XRT) can decrease quality of life (QOL), disrupt cortisol rhythm and contribute to cardiovascular disease. We examined the effects of yoga on buffering changes in QOL...