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
Many stress-related parameters have been associated with antisocial behavior, including low cortisol awakening responses (CAR), as well as low cortisol and alpha-amylase reactivity to stress. These... Show moreMany stress-related parameters have been associated with antisocial behavior, including low cortisol awakening responses (CAR), as well as low cortisol and alpha-amylase reactivity to stress. These parameters reflect different, yet interrelated components of the stress system, yet it remains to be determined whether they exert joint or independent effects. Therefore, this study examined them in concert, as this may offer a better explanation of the psychophysiological mechanism’s underlying antisocial behavior. Antisocial behavior was assessed through self-report by 197 general population boys and girls (Mage = 17.31, SD = 0.44). The CAR was assessed, as well as cortisol and alpha-amylase reactivity to a public speaking task. Neither stress-related parameter was independently related to antisocial behavior. The best explanation was provided by a CAR × Cortisol reactivity interaction, indicating that in youth with a low CAR, antisocial behavior was positively associated with cortisol reactivity. In youth with a high CAR, no association between antisocial behavior and cortisol reactivity was found. Between cortisol and alpha-amylase reactivity a trend toward an interaction appeared, indicating a negative association between cortisol reactivity and antisocial behavior in those with low alpha-amylase reactivity, and a positive association in those with high alpha-amylase reactivity. These findings indicate that in order to understand the mechanisms underlying antisocial behavior, the stress system should be studied comprehensively rather than focus on single parameters. Particularly cortisol parameters appear to be jointly related to antisocial behavior, the additional value of alpha-amylase reactivity to cortisol reactivity may however be limited. Show less
Vries-Bouw, M. de; Jansen, L.; Vermeiren, R.; Doreleijers, T.; Ven, P. van de; Popma, A. 2012
ObjectiveRecently, salivary alpha-amylase (sAA) has been proposed as a suitable index for sympathetic activity and dysregulation of the autonomic nervous system (ANS). Although determinants of sAA... Show moreObjectiveRecently, salivary alpha-amylase (sAA) has been proposed as a suitable index for sympathetic activity and dysregulation of the autonomic nervous system (ANS). Although determinants of sAA have been described, they have not been studied within the same study with a large sample size without potential disturbances of psychopathology. In this paper, we report about correlates of evening sAA in saliva. MethodsIn 487 participants (mean age=42.9years, 59.8% female) without lifetime psychiatric disorders from the Netherlands Study of Depression and Anxiety (NESDA), sociodemographic, health and sampling determinants of sAA levels were examined using multivariable linear regression analysis. sAA was measured in two saliva samples that participants collected in the late evening, at 22:00h and 23:00h, after which these were averaged. ResultsIn multivariate analysis, age (β=0.20, p<0.001) and daily alcohol intake (β=−0.13, p=0.01) were independent determinants of evening sAA levels. Gender, allergy or lung disease, and the use of oral contraceptives were univariate correlates, but no longer associated with sAA in the multivariate model. ConclusionsAge and alcohol use were identified as potential confounding factors that should be taken into account in epidemiologic studies that examine the ANS function using sAA. Show less
This thesis studies the normal developmental pattern of social evaluative fears from childhood to adolescence. We have investigated age differences in self-reported social fears and physical... Show moreThis thesis studies the normal developmental pattern of social evaluative fears from childhood to adolescence. We have investigated age differences in self-reported social fears and physical responses during a public speaking task. In addition, youth's perceptions of speaking in public were studied through a short interview. Finally, two aspects of adolescent development are highlighted, namely resistance to peer influence and self-restraint, in the two concluding chapters. The main finding of the thesis is that social evaluative fears seem to increase with age. However, future research needs to develop more developmentally sensitive measures and further investigate the underlying processes of this increase. Show less