Brain-derived neurotrophic factor serum concentrations in depressive patients during vagus nerve stimulation and repetitive transcranial magnetic stimulation

background: Vagus nerve stimulation (VNS) and repetitive transcranial magnetic stimulation (rTMS) of the dorsolateral prefrontal cortex are brain stimulation techniques used as therapeutic interventions in major depression. Methods: In this study, we report the impact of these stimulation techniques on serum concentrations of brain-derived neurotrophic factor (BDNF) in treatment-resistant patients with a diagnosis of major depression. Results: We found no changes of BDNF serum concentrations and no association of neurotrophin concentrations in serum with clinical parameters in our sample. Conclusions: Our preliminary results suggest that brain stimulation techniques-in contrast to several antidepressant medications-do not change BDNF serum concentrations.