Advanced treatment options are available from a few tertiary centres for patients with the most severe and treatment-refractory forms of depression and obsessive-compulsive disorder. These treatments include ablative neurosurgery and electrical stimulation procedures directed against different neural targets. They include vagus nerve stimulation (VNS) and deep brain stimulation (DBS). Ablative procedures, such as anterior cingulotomy, are the best established of these alternatives, although the newer electrical stimulation procedures confer potential advantages with respect to surgical morbidity and reversibility. Whilst evidence for VNS as an effective therapy for depression is accruing, DBS remains an experimental treatment, with definitive evidence of efficacy awaited. All neurosurgical procedures used to treat psychiatric disorder should be provided by specialist multidisciplinary teams with expertise in the management of psychiatric disorder by pharmacological and psychological treatment methods. All psychiatric neurosurgical procedures should be subject to detailed long-term clinical audit to determine efficacy and adverse effect burden.