Neuropsychological impact of Cg25 deep brain stimulation for treatment-resistant depression: preliminary results over 12 months.

The purpose of this study was to evaluate preservation of cognitive function after deep brain stimulation (DBS) of the subgenual cingulate (Cg25) for treatment-resistant depression (TRD). We have previously reported on the treatment methods, safety, and 6-month clinical outcome (Mayberg et al., Neuron. 2005;45:651-660). Comprehensive neuropsychological assessments tapping 4 domains of frontal lobe function, and general cognitive abilities, were completed before implantation and at 3, 6, and 12 months postonset of continuous DBS in 6 TRD patients. No adverse neuropsychological effects were noted following surgery, onset and maintenance of DBS with the exception of transient motor slowing noted at 3 and 6 months that improved to normative levels by 12 months. Several areas of cognition that were below average or impaired at baseline improved over follow-up, and these changes were not correlated with improvements in mood. Though the sample size is small, these results support cognitive safety of Cg25 DBS for TRD.