Array-based comparative genomic hybridization (CGH) allows high-throughput genome-wide survey for DNA copy number aberrations, providing a powerful tool for investigating genetic disorders and for developing diagnostic and therapeutic targets. Arrays used in this study consist of approximately 43,000 60-mer oligonucleotide probes that span coding and noncoding regions of the whole human genome with an average spatial resolution of around 35 kb. Furthermore, the sensitivity of these arrays is capable of detecting and mapping regions of single-copy losses, homozygous deletions, and amplicons of various sizes even when using full-complexity genomic samples. In this study, the investigators will conduct an array-based comparative genomic hybridization (CGH) with genomic DNA of many affected members from "schizophrenia families" (the investigators classified families according to the presence or absence of two or more affected members) to identify a set of candidate genes associated with this disease. It is hoped that the results obtained from this study will improve the accuracy and efficiency of psychotic treatment.