These include disorders characterized by feelings of extreme sadness and worthlessness, along with reduced interest in previously enjoyable activities. Examples include Major Depressive Disorder and Persistent Depressive Disorder. These episodes are characterized by feelings of a depressed or sad mood along with a lack of interest in activities. It may also involve feelings of guilt, fatigue, and irritability. During a depressive period, people with bipolar disorder may lose interest in activities that they previously enjoyed, experience sleeping difficulties, and even have thoughts of suicide.