Depressive morbidity and gender in community-dwelling Brazilian elderly: systematic review and meta-analysis

BACKGROUND: Although studies indicate that community-dwelling elderly have a lower prevalence of major depression compared with younger age groups, prevalence estimates in Brazil show that clinically significant depressive symptoms (CSDS) and depression are frequent in the older population. However, a systematic review and meta-analysis of prevalence of and factors associated with depressive disorders and symptoms in elderly Brazilians has not previously been reported. The aims were (i) to perform a survey of studies dating from 1991 to 2009 on the prevalence of depressive disorders and CSDS in elderly Brazilians residing in the community; (ii) to determine depression prevalence and identify associated factors; and (iii) develop a meta-analysis to indicate the combined prevalence and the influence of gender on depressive morbidity in this population. METHODS: Studies were selected from articles dated between January 1991 and May 2009, extracted from Medline, LILACS and SciELO databases. RESULTS: A total of 17 studies were found, 13 with CSDS, 1 with major depression alone and 3 with major depression and dysthymia, involving the evaluation of 15,491 elderly people. The average age of participants varied between 66.5 and 84.0 years. Prevalence rates of 7.0% for major depression, 26.0% for CSDS, and 3.3% for dysthymia were found. The odds ratios for major depression and CSDS were greater among women. There was a significant association between major depression or CSDS and cardiovascular diseases. CONCLUSION: The review indicates greater prevalence of both major depression and CSDS compared to rates reported in the international literature, while the prevalence of dysthymia was found to be similar. The high prevalence of CSDS and its significant association with cardiovascular diseases reinforces the importance of evaluating subthreshold depressive symptoms in the elderly in the community.