This thesis aims to further unravel the role of the stress-systems in the pathophysiology of stress-related psychiatric disorders, by exploring elements of regulation and dysregulation of the two... Show moreThis thesis aims to further unravel the role of the stress-systems in the pathophysiology of stress-related psychiatric disorders, by exploring elements of regulation and dysregulation of the two major stress systems (i.e. the ANS and the HPA-axis), and their relation with psychological and psychiatric characteristics. Show less
Center-based child care settings are a common form of non-parental child care for many families worldwide. However, according to earlier studies, children can experience stress when they attend... Show moreCenter-based child care settings are a common form of non-parental child care for many families worldwide. However, according to earlier studies, children can experience stress when they attend child care. The aim of the current dissertation was to elucidate the correlates of physiological and behavioral stress (especially around transitions) for young children (aged 0 – 4 years, with a specific focus on infants) and their parents in the context of center-based child care, and to examine whether and how we can support families with the aim of reducing stress. We did this by conducting a meta-analysis, a large-scale correlational study, and a small-scale intervention study combining questionnaires, observations, and physiological measures. Results showed that a significant part of children and parents experienced stress during and beyond the transition to center-based child care, irrespective of the quality of child care, and that several child (age and number of hours at child care) and parental (sensitivity and separation anxiety) factors were correlated. We also identified some clues as to what type of support can be helpful to assist families within this context, with the ultimate goal of promoting well-being in both young children and their parents. Show less
Daskalakis, N.P.; Meijer, O.C.; Kloet, E.R. de 2022
'You can't roll the clock back and reverse the effects of experiences' Bruce McEwen used to say when explaining how allostasis labels the adaptive process. Here we will for once roll the clock back... Show more'You can't roll the clock back and reverse the effects of experiences' Bruce McEwen used to say when explaining how allostasis labels the adaptive process. Here we will for once roll the clock back to the times that the science of the glucocorticoid hormone was honored with a Nobel prize and highlight the discovery of their receptors in the hippocampus as inroad to its current status as master regulator in control of stress coping and adaptation. Glucocorticoids operate in concert with numerous neurotransmitters, neuropeptides, and other hormones with the aim to facilitate processing of information in the neurocircuitry of stress, from anticipation and perception of a novel experience to behavioral adaptation and memory storage. This action, exerted by the glucocorticoids, is guided by two complementary receptor systems, mineralocorticoid receptors (MR) and glucocorticoid receptors (GR), that need to be balanced for a healthy stress response pattern. Here we discuss the cellular, neuroendocrine, and behavioral studies underlying the MR:GR balance concept, highlight the relevance of hypothalamic pituitary-adrenal (HPA)-axis patterns and note the limited understanding yet of sexual dimorphism in glucocorticoid actions. We conclude with the prospect that (i) genetically and epigenetically regulated receptor variants dictate cell-type-specific transcriptome signatures of stress-related neuropsychiatric symptoms and (ii) selective receptor modulators are becoming available for more targeted treatment. These two new developments to 'restart the clock' with the to resilience. Show less
In the present study we measured the concentrations of cortisol, thyroid hormones, testosterone, and GABA (gamma aminobutyric acid) in am blood plasma samples of combatants with an at least 10 year... Show moreIn the present study we measured the concentrations of cortisol, thyroid hormones, testosterone, and GABA (gamma aminobutyric acid) in am blood plasma samples of combatants with an at least 10 year history of military psychological trauma (N = 74) divided in groups that either suffer from post-traumatic stress disorder (PTSD) (N = 37) or are resistant (N = 37) as well as in a control group without traumatic experience in the anamnesis, (N = 34). PTSD symptoms were assessed using the Clinician-Administered PTSD Scale (CAPS). The results show that the am blood cortisol levels of individuals that were exposed to war zone experiences irrespective susceptibility for or resistance to PTSD were significantly higher than the values observed in the controls. Testosterone levels in PTSD patients differed neither from that observed in PTSD resistant nor control groups. In the resistant group testosterone levels were however significantly higher than in controls. The level of all thyroid hormones did not differ between the study groups. GABA level was significantly lower in the PTSD group compared with healthy controls. In the resistant group blood GABA levels were not significantly different from either PTSD patients or controls. In conclusion, the current data show that cortisol and to some extent testosterone may serve as biomarker of war zone stress per se, even if trauma was experienced at least ten years before, rather than of only PTSD or resistance to PTSD. GABA, in contrast, can be considered a potential marker of the protracted nature of PTSD. Show less
Background: Learned placebo effects induced by pharmacological conditioning affect immune and endocrine outcomes and may offer new possibilities for clinical applications. Whether or not cortisol... Show moreBackground: Learned placebo effects induced by pharmacological conditioning affect immune and endocrine outcomes and may offer new possibilities for clinical applications. Whether or not cortisol is subject to this type of associative learning processes, and whether conditioning may affect responses to stress, is currently unclear.Method: A randomized placebo-controlled trial was conducted in 48 healthy young women. During acquisition, participants received a pill containing either 100 mg hydrocortisone (unconditioned stimulus) or placebo, paired with a gustatory conditioned stimulus on three consecutive days. During evocation, all participants received placebo paired with the conditioned stimulus, again on three consecutive days. During the third evocation trial, participants underwent a psychosocial stress task. The main outcome parameter salivary cortisol and secondary outcome parameters salivary alpha-amylase, self-reported positive affect and tension, heart rate, and skin conductance level were measured at several time points.Results: Significant baseline group differences on cortisol were found at several time points, which complicate the interpretation of group differences. During the first evocation session, the conditioned group showed a moderately smaller cumulative decrease in salivary cortisol from baseline than the placebo control group. No significant differences were found between the groups on cortisol during the second and third evocation or in response to stress, nor on other outcome measures.Conclusion: Although the results provide potential further indications for effects of conditioning on cortisol, baseline differences make it impossible to draw clear conclusions. No indications for possible effects of conditioning on the cortisol stress response or autonomous or affective responses to stress were found. Show less
Gelderen, M.J. van; Nijdam, M.J.; Vries, F. de; Meijer, O.C.; Vermetten, E. 2020
Background: Hypothalamic-pituitary-adrenal axis functioning has been related to treatment outcome in posttraumatic stress disorder (PTSD). Previous studies have primarily focused on cortisol levels... Show moreBackground: Hypothalamic-pituitary-adrenal axis functioning has been related to treatment outcome in posttraumatic stress disorder (PTSD). Previous studies have primarily focused on cortisol levels before and after a course of therapy and findings have not been fully consistent. This study investigated session-related cortisol levels in veterans with treatment-resistant PTSD over the course of a novel motion-assisted virtual reality exposure therapy and aimed to determine whether cortisol levels were related to changes in PTSD symptom severity.Methods: Veterans (N = 22) received six exposure sessions during which salivary cortisol samples were collected pre-session, post-session and in the late afternoon following sessions. PTSD symptom severity was assessed by structured clinical interviews at pre- and post-treatment. Average cortisol levels were compared between responders and non-responders. Linear regression analyses were conducted with PTSD symptom change as criterion variable, average cortisol levels as predictor, and timing of sampling and baseline PTSD symptoms as covariates.Results: Responders to treatment tended to have higher average cortisol levels at pre-session (p = 0.064) and postsession (p = 0.050) compared to non-responders. Higher average pre-session and post-session cortisol levels predicted greater PTSD symptom improvement (pre: b = 1.83, p = 0.009; post: b = 3.57, p = 0.004).Conclusion: This study provides preliminary evidence for session-related cortisol as biomarker of response to exposure-based therapies for PTSD. Higher cortisol levels may have facilitated fear extinction and reconsolidation, and may indicate increased physiological stress activation necessary for appropriate treatment engagement. Further work involving comparable methodology is encouraged to establish session-related cortisol as biomarker and to determine the mechanisms through which it interacts with treatment outcome. Show less
In this thesis, we have studied the potential of the zebrafish larval model in studying the ECS, as a complementary model to the existing rodent models. More specifically, we have looked at the... Show moreIn this thesis, we have studied the potential of the zebrafish larval model in studying the ECS, as a complementary model to the existing rodent models. More specifically, we have looked at the role of the ECS in regulating locomotion and anxiety, and its interaction with the hypothalamic-pituitary-interrenal (HPI) axis, or stress axis. This study has provided us with an interesting animal model which allows for pharmacological screening of Cnr1 agonists, and their involvement in the CNS, as shown by a change in locomotion, anxiety-like behavior and HPI axis activity. The zebrafish larval model can be used as a complementary model to the existing rodent animal models, to study the ECS. The zebrafish larval model brings several interesting features, such as optical transparency and possibilities for high-throughput screening. Furthermore, a complete ECS is present, there is lack of endogenous activity, allowing for exogenous compound screening, and zebrafish data is generally in line with rodent literature. Since the ECS is involved in many diseases, more research of this system may result in the discovery of novel drugs and drug targets. Show less
Galbally, M.; Watson, S.J.; IJzendoorn, M. van; Saffery, R.; Ryan, J.; Kloet, E.R. de; ... ; Lewis, A.J. 2020
Understanding fetal programming pathways that underpin the relationship between maternal and offspring mental health necessitates an exploration of potential role of epigenetic variation in early... Show moreUnderstanding fetal programming pathways that underpin the relationship between maternal and offspring mental health necessitates an exploration of potential role of epigenetic variation in early development. Two genes involved in stress response regulation, the glucocorticoid and mineralocorticoid receptors (NR3C1 and NR3C2) have been a focus in understanding stressful exposures and mental health outcomes. Data were obtained from 236 pregnant women from the Mercy Pregnancy Emotional Wellbeing Study (MPEWS), a selected pregnancy cohort, recruited in early pregnancy. Depression was measured using the Structured Clinical Interview for DSM-IV (SCID-IV) and repeated measures of the Edinburgh Postnatal Depression Scale (EPDS). Antidepressant use, stressful events and anxiety symptoms were measured. NR3C1 and NR3C2 DNA methylation was measured in placental and infant buccal samples. Infant cortisol was measured in repeat saliva samples across a task. This study found maternal early pregnancy depressive disorder and symptoms were associated with lower DNA methylation at NR3C2 CpG_24 in placental tissue. There were no significant differences for depression or antidepressant use for DNA methylation of NR3C1. Antenatal depression was associated with lower infant cortisol reactivity at 12 months. DNA methylation in CpG_24 site in NR3C2 in placental samples suppressed the relationship between early maternal depressive symptoms and infant cortisol reactivity. These findings show a relationship between antenatal depression, NR3C2 DNA methylation and infant cortisol response providing support for a specific fetal programming pathway. Further research is required to examine the stability of this epigenetic mark across childhood and long-term mental health outcomes. Show less
Purpose To assess the reliability and safety of a postsurgical evaluation strategy of adrenal function using CRH stimulation and basal cortisol concentrations after transsphenoidal pituitary... Show morePurpose To assess the reliability and safety of a postsurgical evaluation strategy of adrenal function using CRH stimulation and basal cortisol concentrations after transsphenoidal pituitary surgery.Methods Retrospective cohort study of all patients undergoing endoscopic transsphenoidal surgery from 2010 to 2017, in whom early postoperative basal cortisol and/or CRH-stimulated cortisol secretion were available, including confirmation of adrenal function during follow-up. Patients with Cushing's disease were excluded. Optimal test performances were assessed using ROC analysis.Results A total of 156 patients were included. Sensitivity and specificity of the CRH test were 78% and 90%, respectively, and 86% and 92% for basal cortisol, respectively, using an optimal cutoff of 220 nmol/L. Eight patients had false-negative test results with the CRH test (normal test but adrenal insufficient at follow-up), and six patients with basal cortisol, the majority of which had multiple pituitary hormone deficiencies and fluid imbalances. No clinical adverse events occurred in patients with false-negative test results. The diagnostic performance of a single basal cortisol measurement was superior to the CRH test.Conclusions The early postoperative basal cortisol is a safe and simple measurement to guide (dis)continuation of hydrocortisone replacement. However, disturbing factors, e.g., sodium balance disorders, contraceptives, untreated hypopituitarism, and illness impact the interpretation and in those cases this measure is unreliable. We propose an algorithm in which hydrocortisone replacement at discharge is based on basal cortisol <220 nmol/L on postoperative day 2 or 3 in a stable condition. Show less
Understanding maternal mental health and cortisol regulation across pregnancy and the relationship to the development of the offspring's stress regulation Is critical to a range of health outcomes.... Show moreUnderstanding maternal mental health and cortisol regulation across pregnancy and the relationship to the development of the offspring's stress regulation Is critical to a range of health outcomes. The aim of this study was to investigate infant and maternal cortisol in women with depression. Data were obtained from 241 pregnant women within the Mercy Pregnancy and Emotional Wellbeing Study (MPEWS), a selected pregnancy cohort study. Depression was measured using the Structured Clinical Interview for DSM-IV (SCID-IV) and repeat Edinburgh Postnatal Depression Scale (EPDS). Repeated measures of antidepressant use, stressful events, anxiety symptoms and maternal hair cortisol concentrations (HCC) and infant cortisol at 12 months postpartum in saliva and hair. Socio-emotional outcomes were measured at 12 months by maternal report on the Brief Infant and Toddler Socio-emotional Assessment (BITSEA). This study found that maternal depression was not associated with maternal HCC. Anxiety, stress and antidepressant use were not associated with maternal HCC. Independently, higher maternal 3rd trimester maternal depressive and anxiety symptoms were associated with lower infant cortisol response at 12 months of age. A higher number of postpartum stressful events was associated with lower infant cortisol response. Lower infant stress reactivity was associated with higher externalizing symptoms at 12 months of age. Future studies are required to understand implications for later mental health. Show less
Hypercortisolism causes numerous and potentially severe complications, which are often underestimated and not well recognized in clinical practice. There are two main causes for... Show moreHypercortisolism causes numerous and potentially severe complications, which are often underestimated and not well recognized in clinical practice. There are two main causes for hypercortisolism. Firstly, exogenous hypercortisolism through corticosteroid use, which is highly prevalent, since around 1% of the general population uses corticosteroids. Secondly, endogenous Cushing’s syndrome, which is rare, but the disease burden is considerable through increased morbidity and mortality risks. In this thesis, potential complications of exogenous hypercortisolism, and treatment and clinical outcomes of Cushing’s syndrome, are discussed. These studies on various aspects of hypercortisolism emphasize the importance of suppressing cortisol secretion to physiological ranges. Both hypercortisolism and adrenal insufficiency have enormous, and sometimes deleterious, impact on physical and psychological functioning. Treatment of hypercortisolism and adrenal insufficiency attempting to restore normal cortisol concentrations does not eliminate risk of adverse outcomes. Finally, increasing knowledge on the effects of endogenous Cushing’s syndrome and exogenous hypercortisolism is likely to improve patient care beyond the endocrinology department, as these conditions serve as a model for long-term exposure to stress, which is a highly prevalent condition. Insight into the potential consequences of long-term stress exposure, can aid all individuals exposed to long-term stress, including patients with chronic disease or long-term hospital admission. Show less
