Objectives: To test whether contagious depressive symptoms mediate the association between spousal depressive symptoms (spousal-DS) and the other spouse's cognitive function, and test the moderated mediation of social activities engagement and sleep quality.
Study design: A total of 3,230 adults aged ≥60 and one of his/her close relatives were interviewed in 2016 in Xiamen, China.
Methods: Cognitive function and depressive symptoms were measured by MoCA and GDS-15/CES-D-10, respectively. Social activities engagement and sleep quality were self-reported. Mediation and moderated mediation were tested by PROCESS macro with 5000 bootstrapping re-samples.
Result: Among all, 1,193 pairs were husband-wife with complete information and were included. The mean ages of older adults and their spouses were 68.35 ± 6.53 and 66.53 ± 7.91 years, respectively. The mean MoCA and GDS-15 scores for older adults were 22.21 ± 5.45 and 1.73 ± 2.17, respectively. The average score of CES-D-10 for spouses was 14.18 ± 4.77. Spousal-DS were associated with cognitive functions of older adults via the contagious depressive symptoms (indirect effect: -0.048, 95% confidence interval (CI): (-0.075, -0.028)). Such mediation can be buffered by attending social activities (interaction: -0.062, 95% CI: (-0.111, -0.013)) and improving sleep quality (interaction: -0.034, 95% CI: (-0.057, -0.012)).
Conclusion: Cognitive function of older adults was associated with his/her spouse's depressive symptoms, and the association was mediated by contagious depressive symptoms and moderated by social activities as well as sleep quality.
Keywords: cognitive function; sleep quality; social activities; spousal depressive symptoms.