Association of Comorbidity with Depressive Symptoms in Community-Dwelling Older Persons

BACKGROUND: Depression in later life poses a serious threat to mental health and well-being of older persons burdened with medical illnesses. Comorbid medical conditions independently, as well as through interactions, may influence the degree of depressive symptoms manifested by the elderly. Insight into the role medical comorbidity plays in the manifestation of depression may help to better address both physical and mental health care needs of the depressed elderly. OBJECTIVE: To examine independent and synergistic effects of comorbid medical conditions in the presentation of depressive symptoms among older adults living in the community. METHODS: Data from a national survey of community-dwelling older persons aged 60 years and over (n = 2,058) in Korea were used. The levels of depression were assessed using an eleven-item Center for Epidemiological Studies Depression Scale. Comorbidity was defined as the number of chronic medical conditions and the combination of disease pairs. Sociodemographic characteristics, self-rated health, physical functioning, history of hospital admission in the past year, frequency of contact with friends or neighbors, and emotional support were used as covariates. RESULTS: Overall, persons with a medical condition compared to those without tended to show a higher depressive symptom score. Comorbidity, in terms of the number of medical conditions, tended to show a significant linear association with depression, controlling for confounders. More important, independent effects of medical conditions as well as a tendency to synergy among specific medical conditions were found, with notable gender differences. CONCLUSION: Given the significant but complex association of comorbid medical conditions with depressive symptoms in aged persons, clinicians should exercise care to address their physical and mental health needs within a common therapeutic context.