Neuroimaging of Dopamine Metabolism in Normal and Psychiatric Patients

Brain cells communicate with each other by releasing chemicals called neurotransmitters. In order for brain cells to transfer information, one cell will release a neurotransmitter that will be recognized by a receptor located on surface of another cell. One such neurotransmitter is dopamine. Abnormal dopamine transmission has been seen in patients with substance abuse and different neuropsychiatric disorders including schizophrenia. A radioactive drug called IZBM (I-123 iodobenzamide) can also bind to certain dopamine receptors. IZBM can be seen by Single Photon Emission Tomography (SPECT). Therefore, by using IZBM and SPECT scans, researchers can find and "map" the location of dopamine receptors in the brain. Patients participating in this study must also have been selected for other genetic studies being conducted at the NIMH. Patients with schizophrenia will be selected from a NIMH research study titled, "Neurobiological Investigation of Patients with Schizophrenia Spectrum Disorders and Their Siblings" (95-M-0150). Normal patient volunteers will be selected from another NIMH study titled, "Inpatient Evaluation of Neuropsychiatric Patients" (89-M-0160). All aspects of clinical care and genetic analysis of these patients will be covered in these studies, while information pertaining to IBZM SPECT scans will be covered in this study. This study will not directly benefit patients participating in it. However, information gathered may contribute to faster and more accurate diagnosis of schizophrenia and eventually better treatment for the disorder.