The GDS is less valid in assessing cognitively impaired patients. This is not surprising, since asking a person how he has felt in the past week is a recall task (27, p859). In such cases, self-report is commonly supplemented by evidence from an informant. The GDS has not been well validated on the very old. Although it may lack some items relevant to identifying depression, the GDS performs better than most self-rating scales when applied to elderly people. We recommend its use but, as with most self-rating depression scales, it should be followed by a psychiatric interview to confirm the classification.