Medical Student Research Fellowship for Summer 2006

Mentor: Carol A. Tamminga, M.D.
Co-Mentor: Elena Ivleva, M.D.
Department: Psychiatry
Room number: NE5.110F
Mail Code: 9070
Phone number: 214-645-2789
E-mail: carol.tamminga@utsouthwestern.edu
Project title: Neurophysiological and genetic studies in schizophrenia and other psychiatric disorders

Human subjects IRB approved project number (where applicable): 052004-021

Animal subjects IRB approved project number (where applicable): N/A

Project Type (patient-based research, animal-based research, or basic research; this characterization is only to permit a general classification for grouping similar types of projects): patient based research

Brief Description of Project:
Objective:
The overall goal of this study is to characterize the degree of overlap between schizophrenia (SZ) and other psychiatric illnesses (mainly Bipolar I Disorders (BP), Schizoaffective Disorder (SAD)) by studying a broad panel of endophenotypes in affected individuals and their unaffected relatives.
Background: Although epidemiological, family and linkage studies do not suggest that SZ and BP are a single diagnosis, they do show that the two groups of disorders share some genetic risk and may be more closely related than previously thought. Identifying disease-related genetic effects has been a major focus in SZ and BP research in recent years. Although, these studies have identified interesting leads and some replicated "hot spots" on the genome associated with each of the disorder, failures of replication across studies has been one of the most consistent and bothersome outcome. This state of affairs is likely due to the heterogeneous nature of these disorders and lack of clear boundaries of the clinical phenotypes. Investigators are now focusing on alternative phenotypes such as BP with psychosis, P50, PPI and eye tracking abnormality in linkage analysis with some success. Unfortunately, in the existing data sets there is minimal information on alternative neurophysiological or neurocognitive phenotypes, thus limiting the scope of analyses that could be carried in the existing samples. In light of these etiologic complexities there is a critical need for use of alternative phenotypes that reflect specific aspects of disease risk for both SZ and BP.
Methods:
We recruit SZ and BP probands, their family members (1st degree relatives), and control subjects. Recruited individuals undergo an extensive screening process with strict exclusion criteria (i.e. ages younger than 16 and older than 55 years, serious medical conditions affecting brain function, current substance abuse/dependence and extensive drug history, etc.). Once enrolled, all subjects then undergo a series of clinical assessments which include sociodemographic information, medical history, family history, scales rating psychotic, affective, negative symptoms and schizophrenia spectrum personality disorders. We obtain measures of neurophysiological putative endophenotypes (e.g. Smooth Pursuit Eye Movements, evoked potentials (P50, P300) and Repulse Inhibition), neurocognitive function (e.g. IQ level, sustained attention, working and declarative memory, executive function, and problem-solving), and brain structure (structural MRI, Voxel-Based Morphometry). In addition, we collect blood samples in order to obtain DNA for future genetic analysis.
Significance: This study will provide valuable information in unique and overlapping putative endophenotypes and genetic markers in psychosis domain of SZ and BP.

Previous Research Activities or Publications with Medical Students:
Erica N. Effros: summer internship (May-August, 2005)
Anh Nguyen: Joint Admissions Medical Program (JAMP) summer internship (June, 2005)
Jena Shockley: research internship (October, 2005 - February, 2006)
Gloria Baquero: research internship (February - May, 2006)
Jamie Raju (UTSW medical student): research internship (September, 2005 - February, 2006), abstract presentation (January, 2006)

Return to Medical Student Research Page