The purpose of this research study is to test if a reduction in depressive symptoms in response to treatment with an antidepressant improves levels of certain proteins which have been associated with increased risk for the development of Alzheimer's disease (AD). This study will be conducted at New York University Langone Health (NYULH) or Nathan Kline Institute (NKI), and we expect a total of about 150 subjects age 60+ to enroll in the study across the 2 sites to reach a goal of 90 randomized subjects.