Neuromodulation of the NAcc with DBS has been shown to significantly improve symptoms, reduce aberrant NAcc activity and restore altered fronto-striatal connectivity in treatment-resistant OCD [159]. Based on this finding, the authors [159] suggested that, for some patients, dysregulated reward circuit activity interferes with the functioning of other (i.e. fronto-striatal) circuits, and contributes to OCD symptoms, and that this can be effectively reversed with neuromodulation. While originally developed for reward alterations in depression, DBS targeting the medial forebrain bundle (white matter tracts connecting regions of the reward system including the NAcc) also improves symptoms in treatment-resistant OCD [160]. The approach of these studies targeting white matter fiber bundles is in line with recent findings showing the importance of targeting white matter networks rather than discrete cortical targets [70–71].
