Aim: To describe the prevalence and associates of major depression and minor depression among the Finnish non-demented population aged 85 years and older (n = 339).
Methods: DSM-III-R criteria were used in diagnosing major depression and dementia. Minor depression was diagnosed by the physician in those who did not fulfil the DSM-III-R criteria for major depression, but had still at least two depressive symptoms. In the first phase, cross-tabulation was used to determine relative risks (RR) and their 95% confidential intervals (95% CI). An additive logistic regression model was then used to find the independent associates of depressive disorders.
Results: The prevalence of major depression was 8.1% in men and 4.9% in women, and that of minor depression 18.9% in men and 18.5% in women. In men major depression was associated independently with poor physical health and in women with rare contact with family or friends and poor physical health. Minor depression was associated independently with poor physical health and previous myocardial infarction in men and with poor physical health, a poor ability to walk, and smoking in women.
Conclusions: The prevalence of depressive disorders is quite high among the oldest-old Finns. The factors associated with major and minor depression are largely similar. Although the results suggest that psychosocial stress factors affect the development of both major and minor depression in the oldest-old, no conclusions about causality can be made.