Each site will recruit individuals in a large geographic area, and use efficient ascertainment strategies and assessment procedures in order to maximize the number collected. Subjects thought to have schizophrenia will be assessed by personal and family interviews and a review of medical records. Diagnoses will be made by consensus best-estimate procedures. Blood specimens will be obtained from all individuals with schizophrenia or schizoaffective disorder plus their available parents and also the control individuals. A clinical self-assessment will be administered to each control subject. The assessment will include validated self-assessments of lifetime major depression, anxiety disorders, and substance use, and self-reported history of bipolar or psychotic symptoms. Permanent cell lines will be created and DNA extracted at the NIMH-sponsored Center for Genetic Studies. At the end of the four-year project period, biological materials and blinded pedigree and clinical data will be made available to the scientific community for genetic studies of schizophrenia and related disorders. The control sample will, however, be released in a staggered fashion, twice during each fiscal year, to start during the 2nd year of recruitment. The informed consent for controls includes consent for specimens to be used in research on the genetics of any medical disorder. In years 3 and 4, we will undertake association analyses. Power analyses suggest that this study will have excellent power to detect loci associated with genes with relatively small etiologic effects. Data derived from this study will potentially have applications for the treatment and prevention of schizophrenia.