Brain Aging and Treatment Response in Geriatric Depression

This study is designed to conduct a double-blind placebo-controlled trial of Namenda (Memantine) as an augmentation to Lexapro (Escitalopram) in depressed older adults 60 years of age and older. Throughout the course of the study, the investigators anticipate screening about 400 subjects to recruit 134 participants in the first four years. This study will require that the subjects complete up to 20 (twenty) visits in 12 (twelve) months to the study site during their participation. The purpose of this study is to determine whether Namenda (memantine) when taken in combination with Lexapro (escitalopram), may improve the quality of treatment response by making it faster and more complete, and also by improving thinking and memory in comparison to Lexapro taken with a placebo. Enrolled subjects will be provided with 10-20 mg of escitalopram for 12 months, and concurrently randomly assigned to either memantine or placebo groups. The investigators will also examine the safety and tolerability (how well the treatment works and the side effects) of a combination of Namenda and Lexapro as compared to placebo and Lexapro in subjects with major depressive disorder and mild cognitive impairment who are at least 60 years of age. Memantine is likely to accelerate and enhance antidepressant response to escitalopram and improve cognitive performance. Subjects with amnestic mild cognitive impairment or biomarkers of brain aging at baseline are likely to have preferential response to the combination of memantine and escitalopram compared to escitalopram and placebo, thus identifying a more personalized treatment approach in the high-risk subgroups for poor clinical outcomes.