[Neuro-endocrine correlates of burnout]

The symptoms of burnout are similar to those of depression on the one hand and chronic fatigue syndrome on the other hand. However, the neuro-endocrine correlates of these two syndromes are the opposite, the former being a hyperfunction of the hypothalamic-hypophysial-cortical axis (HPA) and the latter being a hypofunction of the hpa-axis.

To find out, via a systematic review of the literature, whether burnout is associated with either a hyperfunction or a hypofunction of the HPA-axis.

We searched PubMed using the following search terms: 'burnout syndrome and burnout', 'adrenocorticotropic hormone', 'corticotropin releasing factor', 'hypothalamic pituitary adrenal axis' and 'cortisol'. We retrieved 16 original articles en one meta-analysis were included in the study.

Functional stress testing showed hypersuppression of the HPA-axis after dexamethasone. Basal cortisol values were found to be less conclusive, although a meta-analysis pointed to a negative association between burnout and cortisol. We did not find any studies that were carried out with the help of physiological, physical or psychological stress factors in burnout.

Burnout is associated primarily with a hypofunction of the HPA-axis, which is a neuro-endocrine characteristic of exhaustion, rather than of depression. However, further studies involving functional stress testing are needed in order to map the neuro-endocrine profile fully and to clarify the link with the deregulation of the immune system.