Children suffering from separation anxiety disorder (SAD) show increased HPA axis activity compared to healthy controls.

RESEARCH QUESTIONS Separation anxiety disorder (SAD) is one of the most common mental disorders in childhood, and one of the earliest emerging. Little is known about the association between SAD and the hypothalamic-pituitary-adrenocortical (HPA) axis activity. Therefore, the present study aimed at investigating this association in children suffering from separation anxiety compared to healthy controls. METHODS A total of 31 children with diagnosed SAD (mean age: 8.45; 17 females, 14 males) and 25 healthy controls (HC; mean age: 9.74; 12 females, 13 males) took part in the study. All participants underwent psycho-physiological testing for HPA axis challenge. Testing consisted of a separation and a social exposure paradigm. Saliva samples to assess HPA axis-related cortisol secretion were gathered in parallel. RESULTS Compared to healthy controls, children with SAD showed greatly increased HPA axis activity, as reflected by an increased cortisol secretion throughout the entire period of investigation. The rise of cortisol was already observed in anticipation of, but not following the separation paradigm. No gender-related differences of cortisol secretion were observed. CONCLUSIONS Separation anxiety disorder (SAD) in children is reflected in greatly increased HPA axis activity. Compared to healthy controls, children with SAD showed increased cortisol values from the beginning of, and throughout, the entire investigation. This pattern of results suggests that both the anticipation of a separation and a persistent hyperactivity of the HPA axis system leads to an increased cortisol secretion.