Hypothalamic Pituitary Adrenal Axis and Prolactin Abnormalities in Suicidal Behavior

Hypothalamic Pituitary Adrenal (HPA) axis hyperactivity measured with the dexamethasonesuppression test and the dexamethesone/CRH test may be found to have some predictive power for suicidal behavior in mood disorders. Increased prolactin (PRL) levels may be related both to physiological and pathological conditions. HPA axis abnormalities and increased levels of PRL may coexist and common neuroendocrine changes may activate both HPA axis and PRL release. HPA axis hyperactivity is presumably present in a large subpopulation of depressed subjects. Suicidal behavior is considered to be a form of inward directed aggression and aggressive behavior has been connected to high androgen levels. However, lower plasma total testosterone levels have also been reported in subjects with depression and higher suicidality. Lipid/immune dysregulations, the increased ratio of blood fatty acids and increased PRL levels may be associated with the increased production of pro-inflammatory cytokines, which were reported both in major depression and suicidal behavior. Although no studies have been done to determine whether antemortem physical stress may be detected by raised post-mortem PRL, this would be of great interest for physicians.

Keywords: Suicidal behavior, stress, prolactin, HPA axis.