Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. Psychosis is a mental illness that interferes with one’s ability to perceive objective reality in an adequate way. Individuals suffering from the disease experience symptoms, such as hallucinations, paranoia and delusional thoughts, that make it difficult to successfully distinguish between reality and imagination. As a result, the mental condition changes behavior and cognitive patterns of the affected individuals. Learn more about the disease, its causes, symptoms and treatment in this book.