Abstract
Psychiatric disorder is a common complication of mental handicap. Whilst there are few detailed studies of psychiatric morbidity in mentally handicapped people, recent epidemiological surveys indicate that approximately 50% of mentally handicapped people in hospital and in contact with services in the community have suffered from psychiatric symptoms or behavioural problems sufficient to require specialist advice. All forms of psychiatric disorder are seen although the pattern differs somewhat from that in the general population and there is a high frequency of behaviour disorders.