Psychosurgery, also called neurosurgery for mental disorder (NMD), is the neurosurgical treatment of mental disorder. It was introduced in 1930s and has a controversial history; Portuguese neurologist Egas Moniz is usually credited with being the originator of psychosurgery, although there had been previous attempts to operate on the brains of mentally ill people.

Currently, interest in the neurosurgical treatment of mental illness is shifting from ablative psychosurgery (where the aim is to destroy brain tissue) to deep brain stimulation (DBS) where the aim is to stimulate areas of the brain with implanted electrodes