Objectives: To assess the extent to which loss of ability to perform everyday activities in early stage senile dementia is worsened by the presence of depressive illness.
Methods: To evolution of disabilities is measured by an activity scale permitting observation of small changes in everyday performance in a cohort of 397 elderly persons with subclinical cognitive deficit. Over the 3 years of the study, 11% of the cohort developed dementia without depression and 5% dementia with depression.
Results: Progressive disablement was found to be greater in persons with senile dementia as compared to normal subjects. Depression alone had no significant effect over the time period. Persons with both senile dementia and depression had significantly higher rates of disability at 3 years than persons with senile dementia alone. Significantly greater decrements across the observation period were observed in dressing, washing, use of telephone and continence in the senile dementia-depression group only.
Conclusion: Depression does not in itself engender significant disability, but interacts with senile dementia to accelerate loss of functioning. Effective treatment of depressive illness in senile dementia may have significant impact on the prevalence and severity of disability.