This study determines the relative effects of functional impairment, cognitive impairment, and duration of care of the elderly on caregivers' depression, and identifies the factors that influence this relationship. The variables were entered individually, based on a logical order in the path modeling. For mediators, the order of three types of social support was assumed to be financial support, instrumental support, and emotional support. The order of five dimensions of caregiver burden was assumed to be impact on finances, feelings of abandonment, impact on schedule, impact on health, and sense of entrapment. Findings indicate that functional impairment had both direct and indirect effects on caregiver depression, and direct effects on impact on schedule, impact on health, and sense of entrapment. The effect of cognitive impairment on caregiver depression was primarily indirect but had direct impact on sense of entrapment. Duration of care had no direct effect on caregiver depression and burden, but did have indirect effects on impact on finances, feelings of abandonment, and impact on health through emotional support. Caregivers of elders with functional impairment were more likely to give care for longer periods, and those who give care for longer periods were likely to receive less emotional support and experience more burden in the dimensions of impact on finances, feelings of abandonment, and impact on health. Caregivers who experience greater impact on finances and impact on health ultimately were at higher risk of depression. The results have important implications for intervention models aimed to increase emotional support for the caregiver. (Contains 3 tables and 1 figure.)