This was introduced in 1936 by Egas Moniz, Professor of Medicine in Lisbon University, for the surgical treatment of certain psychoses (see PSYCHOSIS). For his work in this field he shared the Nobel Prize in 1949. The original operation, known as leucotomy, consisted of cutting white fibres in the frontal lobe of the BRAIN. It was accompanied by certain hazards such as persistent EPILEPSY and undesirable changes in personality; pre-frontal leucotomy is now regarded as obsolete. Modern stereotactic surgery is much more precise in the location of the tissue removed. (see STEREOTAXIS). It may be advised in rare intractable psychiatric illnesses in which the patient is chronically incapacitated, especially where there is a high suicide risk. Patients are only considered for psychosurgery when they have failed to respond to all other therapies. One contraindication is marked histrionic or antisocial personality. Conditions in which a favourable response has been obtained are intractable and chronic obsessional neuroses (see NEUROSIS), anxiety states and severe chronic DEPRESSION.

Psychosurgery is now rare in Britain. The Mental Health Act 1983 requires not only consent by the patient – confirmed by an independent doctor, and two other representatives of the Mental Health Act Commission – but also that the Commission's appointed medical representative also advise on the likelihood of the treatment alleviating or preventing a deterioration in the patient's condition.