Caregivers play a critical role in providing the social support that allows impaired elders to remain at home. The demands of caregiving, however, may stretch the physical and psychological resources of the caregiver, thus jeopardizing the elder. The social support available to the caregiver may help buffer or mitigate the ill effects of caregiving. The purpose of this review is to examine the effect of social support on the development of depression in the caregiver, with a consideration of the components and measurement of social support. The practical as well as the research implications are discussed. Although the anticipated difficulty of caregiving depends on assessment of the elder's mental and functional disability as well, the clinician must not neglect to consider the caregiver's appraisal of the social support available. This assessment need not be elaborate and might include inquiring (1) whether the caregiver has someone in whom to confide; (2) who visits the caregiver, how often, and whether the caregiver is happy with these relationships; (3) what aspects of caregiving are most disturbing; and (4) whether there are symptoms of depression.