Alterations of serum levels of brain-derived neurotrophic factor (BDNF) in depressed patients with or without antidepressants.
BACKGROUND
Because 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.


CONCLUSIONS
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.
Shimizu
Eiji
E
Department of Psychiatry, Graduate School of Medicine, Chiba University, Chiba, Japan.
Hashimoto
Kenji
K
Okamura
Naoe
N
Koike
Kaori
K
Komatsu
Naoya
N
Kumakiri
Chikara
C
Nakazato
Michiko
M
Watanabe
Hiroyuki
H
Shinoda
Naoyuki
N
Okada
Sin-ichi
S
Iyo
Masaomi
M
D000328:Adult; D000368:Aged; D000928:Antidepressive Agents / Q000494:pharmacology / Q000627:therapeutic use*; D015415:Biomarkers / Q000097:blood; D019208:Brain-Derived Neurotrophic Factor / Q000097:blood* / Q000187:drug effects; D016022:Case-Control Studies; D003865:Major Depressive Disorder / Q000097:blood* / Q000188:drug therapy*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged
D000928:Antidepressive Agents; D015415:Biomarkers; D019208:Brain-Derived Neurotrophic Factor