Healthy people experience a range of moods and have a large repertoire of affective expressions. In general, they feel in control of their moods and affects (the outward expression of mood). Mood disorders are a group of clinical conditions characterized by a loss of that sense of control and a subjective experience of great distress.
 
These disorders almost always result in impaired interpersonal, social and occupational functioning. Clients with elevated mood demonstrate euphoria, flight of ideas, decreased sleep and grandiose ideas. Clients with depressed mood experience a loss of energy and interest, feelings of guilt, difficulty concentrating, loss of appetite and thoughts of death or suicide.