Long-term course of brain-derived neurotrophic factor serum levels in a patient treated with deep brain stimulation of the lateral habenula.

Introduction: According to the neurotrophin hypothesis, a brain-derived neurotrophic factor (BDNF) decrease has been postulated as a pivotal pathomechanism in affective disorder, and the treatment-associated increase in peripheral BDNF has been linked to therapeutic efficacy of antidepressant drugs and electroconvulsive therapy. However, in deep brain stimulation (DBS), a still experimental antidepressant treatment approach, this issue has not yet been investigated.

Methods: We examine the long-term course of serum BDNF levels in a 64-year-old woman who is being treated with DBS of the lateral habenula for severe major depressive disorder.

Results: Our main findings are a significant increase in BDNF serum levels following DBS of the lateral habenula and an inverse U-shaped correlation of depression scores and BDNF levels.

Discussion: The data indicate that DBS, like other effective antidepressant treatments, may contribute to an increase in peripheral BDNF levels, which are thought to reflect central nervous DBS-induced neuroplastic changes. Moreover, our observations underscore the complex nature of disease-associated BDNF alterations. Their identification as either state or trait marker remains controversial and requires larger-scale longitudinal studies.