Descriptive epidemiology of registered mentally retarded persons in Galicia (northwest Spain).

In a cross-sectional epidemiological study of mentally retarded persons registered in the diagnosis and therapeutic guidance centers administered by the Galician authorities, 13,636 retarded persons were identified, 9,357 of whom were severely retarded (IQ less than 50). These figures correspond to prevalence rates of 4.95 and 3.40 per 1,000, respectively. The registered retarded population was categorized by age group when diagnosed, age group on January 1, 1983, sex, level of retardation, etiological diagnosis, associated disorders, family standard of living, schooling, and educational aid received. The results, including prevalence rates, where appropriate, were compared with those reported for other countries.