Major depression affects approximately 1-2% of older adults living in the community but as many as 20% experience symptoms. Researchers from Yale University School of Medicine studied 754 people over 70, starting in 1998. At the beginning of the study, and at follow-up assessments conducted every 18 months participants were asked to provide demographic information, take cognitive tests and report any medical conditions. They were also screened for symptoms of depression during the previous week. Over the course of the study 35.7% were depressed at some point, 17.8% were depressed during two consecutive time periods, 11.2% at three time points, 6.3% at four points and 4.5% at all five. More women than men were depressed at each 18-month follow-up and women were more likely than men to experience depression at consecutive time points.
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