Psychosurgery can be considered an extreme and destructive attempt at controlling human behaviour, involving at least partial death of the personality, irreversible mutilation, or a surgical manipulation of the brain for purely behavioural aberrations of unknown aetiology.
Psychosurgery may be used to deliberately destroy certain areas of the human brain to produce more amenable individuals. The technique is occasionally used to treat violent or criminal behaviour. Post-operative blunting of the personality, apathy and irresponsibility are frequent, and some researchers mention deterioration of the intellect in those of high intelligence. Psychosurgery is subject to strong criticism because of the impossibility of obtaining the informed consent of the psychotic or mentally handicapped patient to such treatment; because of its evolving nature; and because of the lack of a clear indication that alternative treatments have been exhausted.
Although after the operation, the patients may be less subject, or no longer subject at all, to anxieties, fears, or symptoms of violence; but they are reduced to a state (variously describe as 'buffoons', 'clowns', or 'human vegetables') considered by some to be incompatible with human dignity.
While psychosurgery cannot guarantee results (good results are only obtained in about 40% of cases), in carefully screened patients it offers the only hope for ameliorating extreme behavioural disturbances such as uncontrollable violence. It enables some otherwise intractable patients to adapt to society or to become more manageable in institutions.