Effects of escitalopram on serum BDNF levels in elderly patients with depression: a preliminary report

Background and aims Increasing evidence in the literature suggests a link between the brain-derived neurotrophic factor (BDNF) system and adult depression, supporting a role in the pathophysiology of the disease and response to therapy. Few studies have reported BDNF serum levels in elderly depressed subjects and their relationship with antidepressant therapy. The aim of the study was to evaluate BDNF serum levels in naive elderly depressed patients, before and after antidepressant treatment. Methods We enrolled n = 5 elderly naive patients affected by depression, according to the Diagnostic and Statistical Manual of Mental Disorders-IV Text Revision criteria for major depressive episode. BDNF serum levels were evaluated through ELISA method. Cognitive functions were examined by Mini Mental State Examination (MMSE) and severity of depression was assessed by Geriatric Depression Scale (GDS). BDNF levels were measured at baseline (T0) and after 2 months (T2) of escitalopram. Ten healthy elderly subjects were enrolled as a control group. Results The serum BDNF levels in patients (T0) and controls were 11.5 +/- 0.6 and 13.6 +/- 3.4 ng/ml (m +/- SD), respectively. At T2, the patients showed a significant improvement of depressive symptoms (p < 0.05), with a not significant increase of MMSE. The serum BDNF concentrations increased to 16.0 +/- 2.7 ng/ml at T2 (p < 0.05), beyond the levels of BDNF in controls. The increase in BDNF levels was significantly related to the improvement in GDS scores of the patients (r = 0.9, p < 0.05). Conclusions Serum BDNF levels may be considered as a marker of response to antidepressant treatment for depression in the elderly.