**8. DBS in psychiatric disorders**

Psychiatric disorders are assorted conditions affecting multiple pathways with overlap. Such disorders have few (if any) biochemical markers that support treatment and outcomes, and there is a lack of data for its outcome assessment in patients. Thus, this affects the designing of clinical trial studies. In addition, the quality of surgical trials is also hindered due to significant selection barriers [63]. In an attempt to alleviate refractory psychiatric symptoms, numerous prospective studies have been done to evaluate if focal disruption at specific anatomic targets can impact circuitwide or network-wide changes. Though the strategy is enticing, there are still some challenges.
