Brain-derived neurotrophic factor, behavior, and new directions for the treatment of mental disorders.

Brain-derived neurotrophic factor (BDNF), a member of the neurotrophin family of survival-promoting molecules, plays an important role in the growth, development, maintenance, and function of several neuronal systems. The purpose of this article is to point out evidence for the involvement of this molecule in the maintenance of normal cognitive and emotional functioning, and to outline recent developments using BDNF, or the regulation of endogenous BDNF expression, in the treatment of a variety of mental disorders. This article discusses the important role of BDNF in neuronal growth and survival, in modulating neurotransmission, in activity-directed synaptic remodeling, and in adult neurogenesis. We next outline evidence for the involvement of BDNF in complex behaviors such as learning, feeding, locomotion, responses to painful stimuli, and the management of severe stress. Finally, our review focuses on the involvement of BDNF in treatments for clinical depression and other chronic neurodegenerative processes. We discuss the way that current and future treatment development can be guided by our growing understanding of this molecule's actions in the brain and the ways the expression of BDNF can be regulated. Copyright 2003 Elsevier Inc. All rights reserved.