Brain-Derived Neurotrophic Factor and Major Depressive Disorder: Evidence from Meta-Analyses.

Taro Kishi,Toshikazu Ikuta,Nakao Iwata,Reiji Yoshimura

doi:10.3389/fpsyt.2017.00308

Abstract

Accumulating evidence suggests that brain-derived neurotrophic factor (BDNF) is associated with the pathophysiology of major depressive disorder (MDD). In this mini review, we explored the association between BDNF and MDD using meta-analytic evidence. Our findings indicated that the Val66Met polymorphism in the BDNF gene was not associated with MDD or hippocampal volume in patients with MDD. However, plasma/serum levels of BDNF were decreased in patients with acute MDD compared with healthy controls. Both antidepressant treatment and electroconvulsive therapy increased plasma and serum levels of BDNF in patients with MDD. Val66Met polymorphism in the BDNF gene was associated with an antidepressant response in patients with MDD. Taken together, we did not detect any plausible evidence regarding Val66Met polymorphism in the BDNF gene contributing to a risk of MDD. However, peripheral BDNF levels are decreased in patients with MDD, and the polymorphisms are associated with treatment response. In conclusion, BDNF is best understood to be a biomarker for the state of MDD and its treatment response rather than a risk factor for MDD.

Highlights

Brain-derived neurotrophic factor (BDNF) has often been suggested to contribute to the pathophysiology of major depressive disorder (MDD)
They demonstrated that Val66Met in the BDNF gene was not associated with MDD in European (odds ratio = 1.00; 95% confidence interval = 0.93–1.09; p = 0.69; I2 = 48.4%; 24 case–control samples; 15,419 patients and 29,007 controls) and Asian populations
Val66Met in the BDNF gene was associated with bipolar disorder in the European population but not in the Asian population

Summary

Introduction

Brain-derived neurotrophic factor (BDNF) has often been suggested to contribute to the pathophysiology of major depressive disorder (MDD). BDNF plays a major role in neuronal growth and survival, serves as a neurotransmitter modulator, and contributes to neuronal plasticity, all of which are related to MDD. BDNF stimulates and controls the growth of new neurons from neural stem cells (i.e., neurogenesis), and BDNF protein and mRNA have been detected in various regions of the brain, including the olfactory bulb, cortex, hippocampus, basal forebrain, mesencephalon, hypothalamus, brainstem, and spinal cord [1].

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