The Down syndrome advantage: it depends on what and when you measure.

A "Down syndrome advantage"--better outcomes for individuals with Down syndrome and their families than for those with other intellectual/developmental disabilities (IDD)--is reduced when variables confounded with diagnostic category are controlled. We compared maternal outcomes in a longitudinal sample of families rearing children with Down syndrome or other IDD, and found that a Down syndrome advantage is (a) most likely when the metric is about the son/daughter rather than the parent or family more globally, (b) may be present or absent at different ages, and (c) is partially explained by higher levels of adaptive behavior for individuals with Down syndrome. We discuss the importance of multiple measures at multiple times, and implications for family expectations and adjustment at various life stages.