Schizophrenia and bipolar disease are severe mental illnesses that affect thinking, mood and behaviour, and cause lifelong disability. Schizophrenia alone costs the Canadian economy about $2.5 billion per year. While the exact causes remain unknown, both disorders are thought to arise from the interaction of genetic defects with environmental factors. Research into these psychotic disorders lags behind advances in other health fields, so new and innovative research strategies are needed. Studies have shown that certain DNA changes can strongly predispose people to psychotic disorders, but the full scope of DNA changes in schizophrenia and bipolar disease has not been explored. Dr. Robert Holt is using new technology called microarray comparative genome hybridization to scan the entire genome of patients with schizophrenia and bipolar disease to detect losses or gains of DNA. The research could contribute to better understanding of the genetic factors that predispose people to schizophrenia and bipolar disorder, lead to diagnostic tests to identify those at risk, and strategies for early intervention to achieve better outcomes.