Circulating Glial-derived neurotrophic factor is reduced in late-life depression.

BACKGROUND The Glial cell-line derived neurotrophic factor (GDNF) is part of the TGF-β superfamily and is abundantly expressed in the central nervous system. Changes in GDNF homeostasis have been reported in affective disorders. AIM To assess serum GDNF concentration in elderly subjects with late-life depression, before antidepressant treatment, as compared to healthy elderly controls. METHODS Thirty-four elderly subjects with major depression and 37 age and gender-matched healthy elderly controls were included in this study. Diagnosis of major depression was ascertained by the SCID interview for DSM-IV and the severity of depressive symptoms was assessed by the Hamilton Depression Rating Scale (HDRS-21). Serum GDNF concentration were determined by sandwich ELISA. RESULTS Patients with major depression showed a significant reduction in GDNF levels as compared to healthy elderly controls (p < 0.001). Also, GDNF level was negatively correlated with HDRS-21 scores (r = -0.343, p = 0.003). DISCUSSION Our data provide evidence that GDNF may be a state marker of depressive episode in older adults. Changes in the homeostatic control of GDNF production may be a target to development of new antidepressant strategies.