The primary aims of our research are to: (1) examine the relationship of specific cognitive dysfunction in geriatric depression to structural abnormalities and functional measures related to the dopamine (DA) system in geriatric major depression; (2) describe the relationship between mood disturbance of geriatric depression and the functional and structural measures of the DA system; (3) characterize the relationship between behavioral disability of geriatric depression and the functional and structural measures of the DA system. The main focus is on integrating neuroimaging data with other neurobiologic and clinical features in geriatric depression.

In our preliminary efforts:

1. We observed that plasma DA metabolite homovanillic acid (HVA) concentration correlated with cognitive functioning as measured by the Mini-Mental State examination.

2. Using high resolution, axial proton density MRI, and a systemic sampling stereologic method we observed that caudate nuclei volume correlated with measurement of behavioral disability and cognitive dysfunction in geriatric major depression. In contrast, the putamen nuclei correlated only with severity of depression.

Our plan is on using more advanced morphometric methods and functional magnetic resonance imaging.