Neurophysiological Studies in Schizophrenia and Psychiatric Disorders
Condition: Schizophrenia; Schizoaffective Disorder; Bipolar Disorder
MeSH terms: Schizophrenia; Bipolar Disorder; Psychotic Disorders; Mental Disorders; Problem Behavior
Study type: Observational

Summary: 
      The overall goal of this project is to identify intermediate phenotypes for psychosis across
      the schizophrenia and bipolar disorders boundary with implications for future genetic
      studies. Recent studies provide considerable evidence that schizophrenia and psychotic
      bipolar disorder may share overlapping etiologic determinants. Identifying disease-related
      genetic effects is a major focus in schizophrenia and bipolar research, with enormous
      implications for diagnosis and treatment for these two disorders. Efforts have been
      multifaceted, with the ultimate goal of describing causal paths from specific genetic
      variants, to changes in neuronal functioning, to altered brain anatomy, to behavioral and
      functional impairments. Parallel efforts have identified and refined several alternative
      endophenotypes that are stable, heritable, have (partly) known biological substrates, and are
      associated with psychosis liability. Although many such endophenotypes have been individually
      studied in schizophrenia, and to a lesser extent in bipolar disorder, no study has
      comprehensively assessed a broad panel of these markers in the two disorders with parallel
      recruitment, and the extent to which they mark independent aspects of psychosis risk, or
      their overlap in the two disorders. In this research project, we will examine a broad panel
      of putative endophenotypes in affected individuals and their first degree, biological
      relatives in order to: 1) characterize the degree of familial phenotypic overlap between
      schizophrenia and psychotic bipolar disorders; 2) identify patterns of endophenotypes unique
      to the two disorders; and, 3) contrast the heritability of endophenotypes across the
      disorders. We will obtain measures of neurophysiology (e.g., eye tracking, P50 gating, PPI,
      and P300), neurocognition (e.g., attention/vigilance, episodic and working memory), and brain
      structure (e.g., volumes of gray and white matter in specified brain regions). Blood samples
      will also be collected and stored for formal DNA linkage analyses using the independent
      phenotypes identified above. All volunteers will also be given the option to donate dermal
      biopsies for future research studies.

      Establishing similarities and differences in the endophenotypic signatures within
      schizophrenia and bipolar families will provide important insights for future genetic
      studies, and clarify concepts about common and distinct aspects of pathophysiology,
      potentially meaningful heterogeneity with disorders, and the clinical boundaries of the two
      most common psychotic disorders in adult psychiatry. This line of investigation will
      potentially impact our conceptualization of psychotic disorders, help us make critical
      strides to identify the pathophysiology of psychosis, and guide development of new specific
      treatments targeting particular deficits.
    


Observational model: Family-Based
Time perspective: Cross-Sectional
Sampling method: Non-Probability Sample
Study population: 
        Individuals with schizophrenia, schizoaffective, or bipolar I disorder.
      
Biospecimen description: 
      Blood, no more than 30cc; urine, small collection cup (about 30cc) to administer drug urine
      screen and pregnancy tests for females; buccal swabs (at least 5 swabs from volunteers that
      cannot donate blood); and, optional: 4mm punch of skin for dermal biopsy.
    
Keywords: Schizophrenia; Schizoaffective disorder; Bipolar disorder; Psychosis; Genetics; Phenotype