Assessment of depression in mentally retarded adults: reliability and validity of the Children's Depression Inventory (CDI).

The applicability of the Children's Depression Inventory (CDI) in the informant-rating version to mentally retarded adults (> 19 years of age) of all degrees of severity is researched here for the first time. The sample (N = 798) consisted of residents in community-based group homes (56.9%) and residents of a variety of institutions (43.1%). On average, 23 of the 24 CDI items were to be assessed. Internal consistency, interrater reliability, and the item-total score correlations were adequate. The three factors derived from factor analysis were open to clear interpretation. The CDI score proved to be independent of age, sex, and degree of mental retardation. Persons with behavior problems, psychotropic drug treatment, non-Down syndrome status, as well as the residents of a psychiatric clinic, all returned a higher CDI score. Among those having a CDI score > or = 17 (n = 54), there were 57% with DSM-III-R depressive disorders. These results suggest that the CDI in an informant-rating version is suitable as a diagnostic and screening instrument for mentally retarded adults.