A longitudinal study of the relationship between levels of depression among persons with Alzheimer's disease and levels of depression among their family caregivers.

The purpose of this study was to examine the effects, over time, of depressive symptoms in persons with Alzheimer's disease on depression in their family caregivers. In a sample of 353 patients and caregivers, multilevel longitudinal analysis was used to accommodate an observational design in which the number of observation points and the intervals between points varied across caregivers. The rate of change (increase) in caregiver depression was predicted by the rate of change (increase) in patient depressive symptoms and by increase in patient dependency in instrumental activities of daily living (ADLs). Acceleration of the increase in caregiver depression was predicted by acceleration in patient dependency in instrumental and basic ADLs but not by acceleration in patient depressive symptoms. These findings indicate the importance of measuring the rate and acceleration of change in patient characteristics in order to understand caregiver depression. They also support early interventions for caregivers.