Functional limitations and somatic diseases are independent predictors for incident depressive disorders in seniors: Findings from a nationwide longitudinal study

Purpose: Few nationwide comprehensive studies analyzed the factors leading to the onset of depression in correlation with medical disease and other related factors concerning geriatric depression. This study examined medical diseases with other factors which lead to depression among the elderly.

Methods: This Taiwan-based longitudinal study examined a collection of 1467 seniors aged over 65. Subjects who fit this criteria were initially interviewed in 2003, and then four years later. Independent variables included baseline demographics, chronic medical illnesses, and the change of subjects' self-perceived health status, functional limitations including ADL, IADL and mobility limitation factors. The dependent variable was the symptoms of incident depression, as ascertained by the ten-item questionnaire during the later session. The logistic regression analyses were used to examine some of the predictors related to depressive disorders.

Results: The findings showed that heart conditions (adjusted OR=1.55, 95% CI: 1.12-2.15, p=0.008) and joint disorders (adjusted OR=1.51, 95% CI: 1.09-2.09, p=0.013), as well as functional limitations, particularly IADL (adjusted OR=1.81, 95% CI: 1.24-2.65, p=0.002) and ADL (adjusted OR=1.77, 95% CI: 1.27-2.47, p=0.001) were independently associated with the onset of depression among the elderly population.

Conclusion: These findings indicated that when classifying symptoms of depression in geriatric patients with several underlying medical diseases, keen attention should be directed to the type of medical disorders and the functional deterioration in terms of daily activities and autonomic capabilities.