Plasma Brain-Derived Neurotrophic Factor as a Candidate Bio-Marker of the Neuroplastic Changes Related with Fluoxetine Administration in Major Depressive Disorder

Original Article

Psychiatry Investigation 2006;3(2):63-72.

Tae-Young Hwang, MD, MPH1;Shinn-Won Lim, MS2;Jihea Yun, MA2; and Doh Kwan Kim, MD, PhD1.2;

¹;Department of Psychiatry, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, ²;Center for Clinical Research, Samsung Biomedical Research Institute, Seoul, Korea

Abstract

Objective

:
The aim of this study was to investigate whether plasma brain-derived neurotrophic factor (BDNF) could be a biological marker related to the pathophysiology of depression and the action mechanism of antidepressants in patients with major depressive disorder (MDD).

Methods
and Materials:
Forty-nine patients with MDD and 34 normal controls were recruited and analyzed for this study. The severity of depression was measured using the 17-item Hamilton Rating Scale for Depression (HAM-D-17) for MDD patients before and after a 6-week treatment with the antidepressant, fluoxetine. A minimum baseline HAM-D-17 score of 15 was required for study inclusion. The plasma BDNF was measured in all subjects at baseline and after the 6-week treatment (for the patients). Treatment outcome was measured as response (≥50% improvement on HAM-D-17) and remission (final HAM-D-17 score ≤7).

Results

There were no significant differences in age and gender distribution, or in baseline plasma BDNF, between the MDD and control groups. The severity of depression and plasma BDNF level at baseline were not significantly correlated. There was no significant change in the plasma BDNF of the MDD group after the 6-week treatment, although a modest trend to decrease was noted (Wilcoxon's signed rank test, S=-186.5, p=0.0629). In addition, there was no significant difference in the change of plasma BDNF between responders and non-responders.

Conclusions

The findings of this study do not support the proposed hypothesis that plasma BDNF plays a significant role as a biological marker in reflecting the neuroplastic change related to the short-term effect of anti-depressants in MDD. Nevertheless, the possibility of false negative findings suggests that further studies are necessary to replicate the findings.

Key words BDNF;Plasma;Neuroplasticity;Major depressive disorder;Antidepressant.