Schizophrenia is a mental disorder that generally appears in late adolescence or early adulthood - however, it can emerge at any time in life. It is a mental disorder often characterized by abnormal social behavior and failure to recognize what is real. It is one of many brain diseases that may include delusions, loss of personality (flat affect), confusion, agitation, social withdrawal, psychosis, and bizarre behavior. Individuals with schizophrenia may hear voices that are not there. Some may be convinced that others are reading their minds, controlling how they think, or plotting against them. This can distress patients severely and persistently, making them withdrawn.