Biological Psychiatry, Volume 54, Issue 1 , 1 July 2003, Pages 70-75
Eiji Shimizu (a), Kenji Hashimoto (a), Naoe Okamura (a), Kaori Koike (a), Naoya Komatsu (a), Chikara Kumakiri (a), Michiko Nakazato (a), Hiroyuki Watanabe (a), Naoyuki Shinoda (a), Sin-ichi Okada (a) and Masaomi Iyo (a)
(a) Department of Psychiatry, Graduate School of Medicine, Chiba University, Chiba, Japan
Received 20 September 2002; revised 7 January 2003; accepted 17 January 2003; Available online 1 May 2003.
ABSTRACT:
BACKGROUND:
B ecause researchers have reported that antidepressants increase the expression of brain-derived neurotrophic factor (BDNF) in the rat hippocampus, we investigated whether serum BDNF levels may be used as a putative biological marker for major depressive disorders (MDD).
METHODS:
We measured serum BDNF in the following three groups: antidepressant-naive patients with MDD (n = 16), antidepressant-treated patients with MDD (n= 17), and normal control subjects (n = 50). Patients were evaluated using the Hamilton Rating Scale for Depression (HAM-D). Serum BDNF was assayed with the sandwich ELISA method.
RESULTS:
We found that serum BDNF was significantly lower in the antidepressant-naive group (mean, 17.6 ng/mL; SD, 9.6) than in the treated (mean, 30.6 ng/mL; SD, 12.3; p = .001) or in the control group (mean, 27.7 ng/mL; SD, 11.4; p = .002). There was a significant negative correlation (r = -.350, z = -2.003, p = .045) between serum BDNF and HAM-D scores in all patients. In a preliminary examination, reduced BDNF values of three drug-naive patients recovered to basal levels after antidepressant treatment.
CONCLUSION:
Our study suggests that low BDNF levels may play a pivotal role in the pathophysiology of MDD and that antidepressants may increase BDNF in depressed patients.
Author Keywords: Antidepressants; brain-derived neurotrophic factor (BDNF); major depression; mood disorder; biological marker
Corresponding author. Address reprint requests to Dr. Eiji Shimizu, Department of Psychiatry (K2), Chiba University Graduate School of Medicine, Inohana 1-8-1, Chuou-ku, , Chiba 260-8670, Japan. | 
