Molecular Imaging of Brain Inflammation in Depressive Disorders

In a number of neuropsychiatric disorders such as depression, both brain inflammation and glutamate mediated excitotoxicity (cell death through over-activated stimulation) are suspected to play a key role. It is difficult, if not impossible, to determine the potential destructiveness of the inflammatory response seen in disease states by studying the brain's inflammatory cells (microglia) activity in isolation. The investigators are proposing to develop the means to concurrently study inflammatory response (i.e., microglial activity) and its potentially devastating consequence (i.e., glutamate excitotoxicity) across the entire brain in order to establish the importance of inflammation. In this study the investigators propose a phased clinical study whereby the early-phase involves the development of our capacity to study inflammation-mediated damage to brain cells, followed by a feasibility study in patients with clinical depression that tests whether concurrent inflammation and glutamate excess could be measured in key brain regions associated with a depressed mood state.