Association study between plasma GDNF and cognitive function in late-onset depression

Abstract

Objective: Improving evidence suggest that neurotrophic growth factor systems might be involved in the pathophysiology of major depressive disorder (MDD). The glial cell line-derived neurotrophic factor (GDNF) is a neurotrophic factor from the transforming growth factor-β-family, which plays a role in the development and function of hippocampal cells. This study was aimed to test whether GDNF in plasma was abnormal in late-onset depression (LOD), and whether it was associated with the cognitive impairment of LOD.

Methods: The plasma GDNF levels in LOD patients (n=27) before antidepressant treatment and normal control subjects (n=28) were measured with the ELISA method. All subjects were assessed by neuropsychological tests and Hamilton Depression Rating Scale (HDRS).

Results: The performance of neuropsychological tests of the LOD group except TMT-B was significantly poorer than those of the control group. The plasma GDNF levels in LOD patients were significantly increased compared to control subjects (P<0.05). Furthermore, the increase of plasma GDNF level was significantly positively correlated with Digit Span Test backward score in LOD patients, and negatively associated with TMT-B performance.

Conclusions: The findings suggest that LOD patients in acute phase have extensive impairments of cognitive function, and higher plasma GDNF might be involved in the pathogenesis of LOD, which may be associated with the cognitive dysfunction in LOD.