Effects of the Addition of Metyrapone to Antidepressant Therapy in Depression With Dexamethasone Suppression Test Non-suppression.

The hypothesis of a link between depression and Hypothalamic-Pituitary Axis (HPA) dysfunction is now experienced. Since a first description in 1949 this link has made the HPA one of the most investigated hormonal axis in depression. Many studies have demonstrated quantitative variations of circulating cortisol in situation of depression including increasing of basal concentration of blood cortisol or Adrenocorticotropic Hormone (ACTH). Furthermore there is an attenuated negative feedback performance of the blood cortisol on the release of ACTH and cortisol. This attenuation seems to be a consequence of a bluntness of sensibility of the hypothalamic cells and their Glucocorticoids Receptors type 2. Actually it seems that these phenomena are included in a diversion of the cortisol\'s action. From a function of acute stress management, with short-time exposures, the cortisol become one of the factors increasing an allostatic load, or resulting of this increase, maintaining a permanent state of stress, an inertia delay to adaptation and facilitating the emergence of psychiatric disorders. This lack of function can be estimated by the Dexamethasone Suppression Test (DST) which, by stimulation attempting of feedback mechanisms by Dexamethasone (which has cortisol-like properties), can show a non-suppressor population with HPA bluntness. If this biological feature isn\'t a biological marker of depression, because of a lack of specificity and sensibility, is notably associated with a poor outcome and higher risks of suicidal behaviors and pharmacological resistance. Many studies have explored possibilities of action on the HPA to treat depression or improve antidepressant specific therapeutics, with inconstant results. One of the most promising molecule seems to be Metyrapone, a reversible inhibitor of the 11ß-hydroxylase enzyme which transform desoxycorticosterone and 11deoxycortisol to respectively corticosterone and cortisol. There have been several open label studies which aim to explore the possibility of an effect of the combination between Metyrapone and antidepressant molecules. This led to two randomized double blind controlled versus placebo studies whose conclusions are divergent. These conclusions and their heterogeneity lead to think that there is a sub-population which could be better responder to this type of association. Physiopathological knowledges and preliminary observations in DST non-suppressor population by using anti-glucocorticoids therapies , makes it possible to consider possible that responsive sub-population can be defined by the feature \" DST non-suppressor \".