Depression among the oldest old: the Umeå 85+ study.

OBJECTIVES

To investigate the prevalence of depression among the oldest old and to analyze factors associated with depression.

METHODS

A cross-sectional, population-based study was undertaken in Umeå, Sweden. Out of 319 eligible participants aged 85, 90 and 95 years and older, it was possible to evaluate 242 people (75.9%) for depression. Data were collected from structured interviews and assessments in the participants' homes, and from medical charts, relatives and caregivers. Depression was screened for using the Geriatric Depression Scale-15 and further assessed with the Montgomery-Asberg Depression Rating Scale. Cognition was assessed using the Mini-mental State Examination, activities of daily living (ADL) using the Barthel ADL Index, nutrition using the Mini Nutritional Assessment and well-being using the Philadelphia Geriatric Center Morale Scale.

RESULTS

The 85-year-olds had a significantly lower prevalence of depression than the 90- and 95-year-olds (16.8% vs. 34.1% and 32.3%). No sex differences were found. One-third of those with depression had no treatment and among those with ongoing treatment 59% were still depressed. Persons diagnosed with depression had a poorer well-being and a higher 1-year mortality. Logistic regression analyses showed that depression was independently associated with living in institutions and number of medications.

CONCLUSION

Depression among the oldest old is common, underdiagnosed and inadequately treated, and causes poor well-being and increased mortality. More knowledge about depression is essential to improve the assessment and treatment of depression among the oldest old.