The hypothalamo-pituitary-adrenal axis in major affective disorder: a review

This paper reviews studies of the hypothalamo-pituitary-adrenal (HPA)-axis activity in patients with affective disorders. It is concluded that, despite methodological drawbacks in most studies, dysregulation of the HPA axis seems to be a consistent finding in a proportion of patients with affective disorder. The HPA axis is a complex neuroendocrine network with multiple integrated levels of control, and it is likely that the dysregulation involves abnormalities at several sites within the axis. At present, it is not clear whether the abnormalities are related to the affective episodes only or to the disorder itself. There is a need for prospective studies of larger samples of patients to be followed during successive affective episodes with a combination of measurements of the HPA-axis activity and brain imaging.