Associations between HPA axis functioning and level of anxiety in children and adolescents with an anxiety disorder.

The hypothalamus-pituitary-adrenal (HPA) axis becomes active in response to stress. Hence, increased levels of anxiety in children and adolescents may be associated with changes in HPA-axis functioning. The aim of this study was to test if level of anxiety or specific anxiety disorders were associated with basal HPA axis activity in children and adolescents with an anxiety disorder. In 99 8- to 16-year-olds with an anxiety disorder, basal cortisol levels were assessed. It was tested if (1) cortisol levels correlated with the level of self-reported anxiety and (2) if cortisol levels were different for individuals with different anxiety disorders. In girls, low levels of anxiety were associated with a stronger rise in early morning cortisol concentrations. In both boys and girls, harm avoidance predicted low cortisol concentrations after awakening. Separation anxiety and physical anxiety symptoms predicted cortisol concentrations at noon. Differences between individuals with different anxiety disorders were not found. More research is needed regarding mechanisms that explain the associations that were found, and to investigate if treatment may influence HPA axis functioning in children and adolescents with an anxiety disorder.

Early attention processes and anxiety in children.

It has been hypothesized that anxiety in children is associated with attentional bias in the early stages of information processing. Bias towards threat indicates the tendency of an individual to direct attention towards threatening information. The aim of the present study was to investigate whether high test-anxiety in a sample of nonreferred children is associated with attentional bias towards threat pictures, and if low test-anxiety is associated with attentional bias away from threat pictures. A probe-detection task was used with 44 10- to 13-yr.-old children. The overall analyses indicated the presence of an attentional bias away from threatening pictures in these nonreferred children. However, in relation to anxiety, the study did not confirm that high anxious children show an attentional bias towards threatening pictures or that low anxious children show an attentional bias away from threatening pictures. Yet, higher anxiety did seem to be associated with longer mean response times. These longer response times might originate from the interpretation of the nature of a stimulus as too threatening, compared to the actual threatening content, in the first stage of information processing. This finding could be useful to improve treatment methods aimed at anxiety symptoms during childhood.