Neuroendocrine responses to psychological stress in adolescents with anxiety disorder

Neurotransmitter-neuroendocrine and cardiovascular responses to the administration of a psychologically stressful mixed-model test (Mental Arithmetic, Stroop Color Word Interference Task, Trier Social Stress Test) were examined in 20 male peripubertal subjects affected by anxiety disorder (group A: 14 with generalized anxiety disorder, 6 with generalized anxiety disorder and separation anxiety disorder) and 20 junior school adolescents, matched for age, without overt psychological disorders (group B). Plasma levels of norepinephrine (NE), epinephrine (EPI), adrenocorticotropic hormone (ACTH), beta-endorphin (beta-EP), cortisol (CORT), growth hormone (GH), prolactin (PRL) and testosterone (Te) were measured immediately before the beginning of the tests and 30 min later at their end. Mean prestress values of GH, PRL, beta-EP and ACTH were significantly higher in anxious subjects than in controls. There was no difference in NE, EPI, CORT and Te prestress levels in the two groups. After the psychological stress session NE, GH and Te concentrations increased significantly in anxious subjects (A), but not in controls. In contrast, beta-EP and PRL decreased significantly during the psychological stress session in anxious subjects, and were unaffected by stress in the subjects without anxiety. No significant changes were found in ACTH, CORT and EPI during the challenge either in anxious subjects or in controls, which may be attributed to the late time of poststress blood sampling. In contrast to controls, heart rate and systolic blood pressure increased significantly in anxious subjects after psychological stress testing. Our data support the hypothesis that the hyperactivity of the noradrenergic system in response to stress is associated with anxiety disorders in adolescents and might influence the responses of GH and Te. High prestress basal values of stress hormones seem to be induced in anxious subjects by the anticipation of the task or by a persistent hyperactivity of the noradrenergic system. Further studies are needed to investigate in more detail the involvement of the HPA axis in anxious adolescents by a more refined resolution of time points of blood sampling.