The natural history of behavioural symptoms among severely and profoundly mentally retarded patients

In a study of the evolution of behavioural symptoms in severely and profoundly mentally retarded adults in hospital over a period of six years, items of abnormal behaviour were found to be remarkably persistent. There is a high prevalence rate of psychiatric disorder in this population, when this disorder is defined in a widely descriptive sense. A substantially improved living environment, and increased staff-patient ratios, are prerequisites for improving disturbed behaviour in these patients.