Neuroendocrine aspects of suicidal behavior.

To assess biologic risk factors in suicidal behavior accurately, it is necessary to distinguish prospective from retrospective design. The former studies are more likely to elicit information concerning possible risk factors in suicide, whereas the latter may be better indicators of biologic traits. In both types of investigations, measures taken close to the suicide attempt are more likely to reflect the biologic state of the individual at the time of the behavior. Although the abnormalities present in suicidal individuals are not entirely clear, most evidence to date suggests an overactivity of the hypothalamic-pituitary-adrenal axis and a dysregulation of both serotonin and adrenergic metabolism. These systems are interrelated. Both animal and human studies have established that a multivariate biologic approach is necessary to the understanding of the pathophysiology of suicide.