Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. The term mood disorders is used to describe a group of diagnoses, where a disturbance in the person's mood is thought to be the main underlying attribute. These mood disorders are generally divided in two categories, based on whether the person has ever had a manic or hypomanic episode. Learn more about the many various types of mood disorders, their possible causes and effects in the following page.