tract Salivary alpha-amylase (sAA) increases rapidly in response to psychosocial stress in young adults, but no direct comparisons between different age groups across the life span have been made. Secretion of sAA and cortisol was assessed in children, young adults, and older adults after exposure to the Trier Social Stress Test. Additionally, cardiovascular activity was measured in both adult groups. Older adults showed attenuated sAA, heart rate (HR), and heart rate variability (HRV) responses. Furthermore, we found higher sAA but lower cortisol at baseline as well as lower sAA and cortisol responses in children. Age x sex interactions were observed only for cortisol with higher responses in older male participants. No associations between the parameters were found. These results implicate sAA as an alternative or additional sympathetic stress marker throughout the life span, with marked and rapid stress responsiveness in three relevant age groups.

There has been significant controversy whether stressful life events (SLEs) experienced over the lifespan may elevate the risk of depression in individuals who are homozygous for the short (S) allele of the repeat length polymorphism (5-HTTLPR) in the regulatory region of the serotonin transporter gene (SLC6A4), compared with individuals homozygous for the long (L) allele. On the basis of the hypothesis that age may be a critical variable, by which such a gene-by-environment interaction may be present in younger adults, but not in older adults and in children, aim of this study was to investigate the role of 5-HTTLPR and SLEs on the endocrine stress response in multiple age cohorts. A total of 115 children (8-12 years), 106 younger adults (18-31 years), and 99 older adults (54-68 years) were subjected to the Trier Social Stress Test (TSST) and structured interviews on SLEs. The TSST induced significant endocrine stress responses in all groups. There was a main effect of genotype in younger and older adults with individuals homozygous for the more active L allele showing a significantly larger cortisol response to the TSST than individuals carrying at least one of the low-expressing S alleles. As predicted, 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.

No abstract

The definition of generalized anxiety disorder (GAD) has been narrowed in successive editions of DSM by emphasizing intrusive worry and deemphasizing somatic symptoms of hyperarousal. We tried to determine the clinical characteristics of more broadly defined chronically anxious patients, and whether they would show physiological signs of sympathetic activation. A group whose chief complaint was frequent, unpleasant tension over at least the last six weeks for which they desired treatment, was compared with a group who described themselves as calm. Participants were assessed with structured interviews and questionnaires. Finger skin conductance, motor activity, and ambient temperature were measured for 24h. Results show that during waking and in bed at night, runs of continuous minute-by-minute skin conductance level (SCL) declines were skewed towards being shorter in the tense group than in the calm group. In addition, during waking, distributions of minute SCLs were skewed towards higher levels in the tense group, although overall mean SCL did not differ. Thus, the tense group showed a failure to periodically reduce sympathetic tone, presumably a corollary of failure to relax. We conclude that broader GAD criteria include a substantial number of chronically anxious and hyperaroused patients who do not fall within standard criteria. Such patients deserve attention by clinicians and researchers.

Dopamine and norepinephrine are key regulators of cognitive and affective processes. The enzyme catechol-O-methyltransferase (COMT) catabolizes catecholamines and the COMT Val158Met polymorphism has been linked to several neuropsychiatric variables. Additionally, stressful life events (SLEs) contribute substantially to affective processes. We used the stress-induced activation of the hypothalamic-pituitary-adrenal axis to investigate the effects of COMT and SLEs on the cortisol response in 119 healthy children (8-12 yr). Saliva cortisol was measured during and after the Trier Social Stress Test for Children. SLEs were assessed with a standardized interview with one of the children's parents. Linear regression analysis revealed a significant effect for COMT, with Met allele carriers showing a higher cortisol response (β=0.300, p=0.001). In turn, more SLEs lead to a less pronounced cortisol increase (β=-0.192, p=0.029) probably indicating increased resilience. Our results further underscore the essential and differential role of genetic variation and environmental factors on stress responsivity.