[Depression in the elderly: prevalence and associated factors]

To determine the prevalence of depression, and to study the factors associated with it among community-dwelling 85-year-olds.

A cross-sectional study was conducted within the framework of a randomized clinical trial in elderly people, all born in 1924, from seven urban and rural primary health care centers. Sociodemographic data and geriatric assessment were performed. Functional status was measured with Barthel index and Lawton index, cognitive impairment with Mini-mental Status Examination, social risk with Gijon test, and comorbidity by Charlson index. The presence of exhaustion and physical activity were recorded along with the chronic prescription of psycothropic drugs, and the presence of depression in clinical registers. Depression was evaluated using the Yesavage Geriatric Depression Scale (GDS) of 5 items (depression ≥ 2). The statistical program used was the R project: (version 2.12.2) Foundation for Statistical Computing, Vienna.

The sample was consisted of 220 subjects, 129 women (58.6%), 76 (34.5% were depressed using the GDS, 46 (20.9%) subjects had depression in the clinical records, and 60 (35.5%) patients were taking antidepressant drugs, 66 (36,8%) benzodiazepine, and 10 (4%) antipsychotic drugs. Depression was associated with poorer functional status according to basic and instrumental activities of daily living, cognitive impairment, exhaustion, low physical activity, and psychotropic drugs. Finally, the factors significantly associated with depression were low physical activity and increased exhaustion.

The present study found a high prevalence of depression in subjects older than 85 years. Physical activity and having a good self-perception of energy are associated to a lower prevalence of depression.