Association of serum nitric oxide levels with depressive symptoms: A studywith end-stage renal failure patients

Background: Nitric oxide (NO) is a soluble gas produced by the activity of an enzyme found in neurons. It has been implicated in a great number of nor mal physiological functions (such as noradrenaline and dopamine release, me mory and learning, regulation of the cerebrovascular system, modulation of wakefulness, modulation of nociception, olfaction, food intake and drinking ) as well as pathologies (Alzheimer's, Huntington's disease, cerebral ische mia, stroke). Two reports have addressed the involvement of NO in depressio n. Methods: The objective of the study was to examine the association betwe en NO and specific depressive symptoms. For this purpose, in a sample of 28 end-stage renal failure patients (who have increased NO levels), we tested the hypothesis that the subgroup of patients with these specific depressiv e symptoms was differentiated from the patients without these symptoms with regard to serum levels of NO metabolites. The depressive symptoms were ass essed using the Zung self-rating scale. Results: Our study revealed an asso ciation of NO with the following depressive symptoms: sexual dysfunction, w eight loss, psychomotor retardation, indecisiveness and irritability. Concl usion: The association between NO system and symptoms of depression does no t necessarily imply a pathogenetic association between NO and depressive di sorder. Further research is needed to verify these findings and study their possible pathogenetic implications. Copyright (C) 2001 S. Karger AG, Basel .