Risk factors for late-life depression and correlates of antidepressant use in Costa Rica: Results from a nationally-representative longitudinal survey of older adults.

BACKGROUND: Risk factors for late-life depression have been studied in high-income countries, but there have been no longitudinal studies from middle-income countries. This study reports risk factors for late-life depression and correlates of antidepressant using the Costa Rican Longevity and Healthy Aging Study (CRELES), a nationally representative cohort of adults age 60 and over.

METHODS: CRELES contains baseline interviews in 2005 (n=2827) with follow-up interviews in 2007 and 2009. CRELES used the Geriatric Depression Scale Short Form to identify depression using cut-offs for mild and severe depression and contained a 14-question assessment to determine physical disability. Participants self-reported antidepressant use and chronic health conditions. We examined correlates of newly screened depression and new antidepressant use among participants not depressed or not using antidepressants in the previous study wave. We used generalized estimating equations to estimate the association among variables.

RESULTS: Increases in disability were associated with newly screening for mild and severe depression. New medical conditions and recent widowhood were associated with newly screening for severe depression. Recent widowhood was also associated with new use of antidepressant medication.

LIMITATIONS: Limitations of this study include absence of persons living in institutions, inconsistency of screening tools with clinical diagnoses, and possible effects of stigma and recall bias on screening.

CONCLUSIONS: Risk factors for late-life depression in Costa Rica are similar to risk factors in high-income countries. Patterns of antidepressant use suggest providers may recognize the role of bereavement as a risk factor for late-life depression but not of disability or chronic conditions.