Depersonalization-derealization disorder occurs when you persistently or repeatedly have the feeling that you're observing yourself from outside your body or you have a sense that things around you aren't real, or both. Feelings of depersonalization and derealization can be very disturbing and may feel like you're living in a dream. This disorder is more common in people who've had traumatic experiences. This disorder can be severe and may interfere with relationships, work and other daily activities. The main treatment for depersonalization-derealization disorder is talk therapy (psychotherapy), although sometimes medications also are used.