Effects of Drugs on Cerebral Blood Flow in Patients With Mood Disorders

Positron Emission Tomography (PET) is a technique used to investigate the functional activity of the brain. The PET technique allows doctors to study the normal biochemical and metabolic processes of the central nervous system of normal individuals and patients with neurologic illnesses without physical / structural damage to the brain.

When a region of the brain is active, it uses more fuel in the form of oxygen and sugar (glucose). As the brain uses more fuel it produces more waste products, carbon dioxide and water. Blood carries fuel to the brain and waste products away from the brain. As brain activity increases blood flow to and from the area of activity increases also. Knowing these facts, researchers can use radioactive chemicals (H215O) and PET scans to observe what areas of the brain are receiving more blood flow.

Patients diagnosed with mood disorders and healthy volunteers will receive positron emission tomographic (PET) scans with H215O while doing simple tasks. Patients will continue to receive scans while in different mood states and while taking different medications. Patients eligible for this study will be participating in other research studies measuring other clinical and biochemical parameters (mood and anxiety ratings, medication responses, and psychological test results). Information gathered from H215O PET scans measuring blood flow to specific brain areas will be compared to the data gathered from other studies.

Objectives of this study are;

1. To determine differences in blood flow to the brain of patients with mood disorders compared to healthy volunteers. 2. To determine differences in blood flow to the brain of patients with subtype mood disorders (such as unipolar versus bipolar) compared to healthy volunteers.

2. To determine changes in blood flow to the brain of patients with mood disorders who experience spontaneous changes in symptoms

3. To determine changes in blood flow to the brain of patients with mood disorders who receive various kinds of therapy (medication, transcranial magnetic stimulation, etc.)

4. To determine if blood flow to specific areas of the brain can be used to predict how patients will respond to certain types of therapy

5. To compare blood flow changes with various other clinical and biochemical parameters.