Prevalence of depressive symptoms and its associated factors among healthy community-dwelling older adults living in Australia and the United States

Objective: This study was conducted to estimate prevalence rates and factors associated with depressive symptoms indexed by the Centre for Epidemiological Studies-Depression (CES-D-10) score in a large sample of community-dwelling healthy older adults from Australia and the United States. Convergent and divergent validity of the CES-D-10 were also examined.

Methods: A total of 19 114 individuals aged greater than or equal to 65 years old were enrolled from a primary prevention clinical trial. Depressive symptoms were classified using the CES-D-10 score greater than or equal to 8 and greater than or equal to 10. Gender-specific prevalence for subgroups according to sociodemographic characteristics were reported, and factors associated with depressive symptoms were estimated.

Results: The overall prevalence rates of depressive symptoms were 9.8%, 95% CI, 8.5-11.2 and 5.0%, 95% CI, 4.0-6.0, according to the CES-D-10 score greater than or equal to 8 and greater than or equal to 10, respectively. Depressive symptoms were more common in women, individuals with less than 12 years of education, those living alone or in a residential care, ethnic minorities, current smokers, and former alcohol users. Convergent and divergent validities of the CES-D-10 were confirmed by observing strong negative association with the SF-12 mental health component and a modest negative association with SF-12 physical component, respectively.

Conclusions: This study reports the prevalence of depressive symptoms in Australian and US community-dwelling healthy older populations. These findings emphasize the high burden of the condition and factors associated with depressive symptoms, to better inform clinicians and help with early detection and treatment of depression in this age group.