Brain-derived neurotrophic factor and subcallosal deep brain stimulation for refractory depression

Abstract

Objectives. Subcallosal cingulate (SCC) deep brain stimulation (DBS) is a promising experimental treatment for treatment-resistant depression (TRD). Given the role of brain-derived neurotrophic factor (BDNF) in neuroplasticity and antidepressant efficacy, we examined the effect of SCC-DBS on serum BDNF in TRD. Methods. Four patients with TRD underwent SCC-DBS treatment. Following a double-blind stimulus optimization phase of 3 months, patients received continuous stimulation in an open label fashion for 6 months. Clinical improvement in depressive symptoms was evaluated bi-weekly for 6 months using the Hamilton Depression Rating Scale (HDRS). Mature serum BDNF levels were measured before and 9–12 months after surgery. Results. Three patients responded to SCC-DBS: two showed full clinical response (50% reduction in HDRS scores) and one had partial response (35% reduction in HDRS scores) at the clinical endpoint. Interestingly, all four patients showed reduction in serum BDNF concentration from pre-DBS baseline. Conclusions. SCC-DBS for TRD may be associated with decreased levels of serum BDNF. Longitudinal studies with multiple measurements in a larger sample are required to determine the role of BDNF as a biomarker of SCC-DBS antidepressant efficacy.

Key words::

• brain-derived neurotrophic factor
• depression
• deep brain stimulation
• subcallosal cingulate region
• biomarker

Acknowledgements

This study was supported by grants from the Hotchkiss Brain Institute (HBI) Clinical Research Unit, University of Calgary, and Alberta Innovates Health Solutions. We thank Dr G. MacQueen for screening patients, Susan Anderson for stimulus programming, and Ana Andreazza her assistance in analysis of the samples.

Statement of Interest

None to declare.