The Relationship Between Activities of Daily Living and Depression Among Community-Dwelling Older Adults

Background and purpose: Depression has recently become a major public health concern, not only to personal suffering but national economic burden that related morbidity and increased mortality. Physical function such as daily activity have emphasized to reduce the depressive symptoms for older adults who cognitively intact in community-dwelling. Studies have proved physiological mechanism of physical activity that not only associate with depressive symptom, but also mediate the relationship between depression and cognitive decline. Despite accumulative evidence showing the interrelatedness between depressive symptoms and ADLs among older adults, the strength of the association may differ depending on sample characteristics and methodology across the studies. For instance, the strength of the relationship between depressive symptoms and ADLs in aged living at home showed the weak correlation than in institutionalized older adults despite of similar cognitive status. Thus, this study examined this relationship among community-dwelling older adults, via a systematic review and meta-analysis. We synthesized the information obtained to calculate the strength of the relationship.

Methods: Systematic review and meta-analysis were conducted to search the existing published observational literature using 5 electronic databases. Published and unpublished studies measuring the direction and strength of the relationship between depressive symptoms and ADLs were independently extracted by the researchers. Several electronic databases, such as PubMed, EMBASE, PsycINFO, the Cochrane library, CINAHL, and Medline, were used. MeSH terms such as "Aged"[Mesh] OR "Aging"[Mesh] OR "Housing for the Older adults"[Mesh], "Depressive symptoms"[Mesh] OR "Depressive Disorder"[Mesh] AND "Activities of Daily Living"[Mesh] were used to retrieve relevant articles from June 2005 to June 2015. Studies reporting r-values between depressive symptoms and the ADLs of older adults were included in the meta-analysis. relationship is affected by various factors of interest, such as sample and study characteristics.

Results: Of total 11840 studies, 16 studies that reported the association r-values were included in the meta-analysis. A total of 7184 older adults participated in 16 studies, with sample sizes ranging from 44 to 1308. Among the 16 studies, three were designed as longitudinal surveys and the design of remaining studies was cross-sectional. The mean ages of the participants included in these studies ranged from 63 to 84 years. No significant bias was observed for the included studies. The quality of the 16 included studies was assured using the appraisal tool for descriptive/cross-sectional studies. The overall effect size suggested a moderate association between ADLs and depressive symptoms among older adults. The strength of the relationship between ADLs and depressive symptoms tended to be larger in studies in which the majority of the participants were female, under 75 years, and not Asians population. The effect size of residing in a senior residence was significantly greater compared to those studies in which the participants were living at home.

Conclusion: Based on these findings, we provisionally conclude that there is a significant negative association between ADLs and depressive symptoms, and this relationship is of moderate strength. Further meta-analysis should be conducted to confirm this relationship by using data accumulated from individual studies.