ObjectiveThis study examined the moderating effect of overall social support and the different types of social support on cognitive functioning in depressed older adults. We also investigated whether the moderating effect varied according to age.MethodsA total of 2,500 older adults (≥60 years old) from Shanghai, China were enrolled using a multistage cluster sampling method. Weighted linear regression and multiple linear regression was utilized to analyze the moderating effect of social support on the relationship between depressive symptoms and cognitive function and to explore its differences in those aged 60–69, 70–79, and 80 years and above.ResultsAfter adjusting for covariates, the results indicated that overall social support (β = 0.091,p= 0.043) and support utilization (β = 0.213,p< 0.001) moderated the relationship between depressive symptoms and cognitive function. Support utilization reduced the possibility of the cognitive decline in depressed older adults aged 60–69 years (β = 0.310,p< 0.001) and 80 years and above (β = 0.199,p< 0.001), while objective support increased the possibility of cognitive decline in depressed older people aged 70–79 years (β = −0.189,p< 0.001).ConclusionOur findings highlight the buffering effects of support utilization on cognitive decline in depressed older adults. We suggest that age-specific measures should be taken when providing social support to depressed older adults in order to reduce the deterioration of cognitive function.