1/2-Dopaminergic Dysfunction in Late-Life Depression (The D3 Study)

Growing evidence suggests that dopamine contributes to key cognitive, emotional, and motor functions across the lifespan. In Late-Life Depression (LLD), dysfunction in these areas is common, predicts poor outcomes, and manifests as difficulties in motivation and effort along with cognitive and gait impairment. While studies of dopamine function in early and midlife depression primarily focus on individuals' ability to feel pleasure and respond to rewards, they often exclude the cognitive and physical function domains relevant for older adults despite a recognized decline in dopamine function with normal aging. The objectives of this collaborative R01 proposal between Columbia University/New York State Psychiatric Institute and Vanderbilt University Medical Center are to: 1) characterize dopaminergic dysfunction in LLD across cognitive, emotional, and motor domains at several levels of analysis (cellular Positron Emission Tomography \[PET\], circuit Magnetic Resonance Imaging \[MRI\], and behavioral / self-report); and 2) examine the responsivity of dopamine-related circuits and behavior to stimulation with carbidopa/levodopa (L-DOPA).