Schizophrenia is a brain disorder that affects thinking, behavior and emotion. It is caused by genetic and environmental factors interacting. Some signs include hallucinations, disorganized speech and behavior, and lack of normal emotional expression. The disorder is associated with abnormalities in brain structure and function. While the causes are not fully understood, schizophrenia results from complex interactions in the brain rather than a single region. Effective treatment and management of symptoms is possible for many with the disorder.