Natural history of depression in the oldest old: population-based prospective study.

Abstract

Despite its negative consequences, little is known about the natural history of depression in the oldest old. To study the incidence, course and predictors of depression in the general population of the oldest old. The Leiden 85-plus Study is a prospective population-based study of 500 people from their 85th to their 89th birthdays. Depressive symptoms were annually assessed with the 15-item Geriatric Depression Scale, using a cut-off of 4 points. During a mean follow-up of 3.9 years, the annual risk for the emergence of depression was 6.8%. Poor daily functioning and institutionalisation predicted depression. Among the 77 participants with depression at baseline (prevalence 15%) the annual remission rate was ony 14%. In more than half of the participants with a remission of depression, we observed a relapse of depression during follow-up. No predictors of remission could be identified. Among the oldest old, depression is frequent and highly persistent. More active case-finding and treatment would be potentially rewarding.