Bidirectional, longitudinal associations between depressive symptoms and IADL/ADL disability in older adults in China: a national cohort study.

Introduction: Based on the data from the China Health and Retirement longitudinal study (CHARLS), we aimed to investigate the bidirectional relationship between depressive symptoms and functional disability.

Methods: Data were collected across 3 waves from 2013 to 2018. The activities of daily living (ADLs) and the instrumental activities of daily living (IADLs) scales were used to measure functional disability and the CESD-10 was used to measure depressive symptoms. Cross-lagged models were performed to examine cross effect between depressive symptoms and functional disability across three waves.

Results: Data on 10,092(mean [SD] age, 61.98[8.44] years; 3764 females [37.30%]) and 10,180 participants (mean [SD] age, 62.01[8.46] years; 3788 females [37.21%]) in IADL sample and ADL sample were included in the analyses. For IADL disability, the cross-lagged model shows a bidirectional association across three waves; the multivariable GEE model revealed that changes in CESD-10 score across waves were associated with worse IADL disability (β ranges: 0.08-0.10) and vice versa, worsen of IADL disability ascending developing of CESD-10 score (β ranges: 0.09-0.10). For ADL disability, the cross-lagged model shows a bidirectional association across three waves; the multivariable GEE model revealed that changes of CESD-10 score across waves were associated with worse IADL disability (β ranges: 0.08-0.10) and vice versa, worsen of IADL disability ascending developing of CESD-10 score (β ranges: 0.09-0.10).

Discussion: Study findings underscore a significant bidirectional between depressive symptoms and functional disability in older adults. Thus, simultaneous intervention should be taken to manage the mutual development of functional disability and depression.