ABSTRACT
Several lines of evidence demonstrate an association between depressive disorders (DD) and Alzheimer’s disease (AD), both conditions that are characterized by significant cognitive dysfunction. We previously suggested that insulin resistance (IR) is a primary link between DD and AD (1,2). Aside from its other deleterious effects, it is thought that IR causes inadequate glucose metabolism in the brain, resulting in cognitive dysfunction. As we postulated earlier, inadequate glucose utilization resulting from IR underlies neuronal changes in crucial brain regions observed among patients with DD (1,2). Further, such neuronal changes in glucose utilization, if unresolved, may result in treatment-resistant DD, cumulative cognitive impairment, and eventually, neurodegeneration and facilitation of AD onset. Herein, we review the lines of evidence demonstrating the importance of IR in DD and the development and progression of AD.
