- It is manifested by a combination of symptoms that interfere with the ability to work, study, sleep, eat, and enjoy once pleasurable activities. Such a disabling episode of depression may occur only once but more commonly occurs several times in a lifetime.
- involves long-term, chronic symptoms that do not disable, but keep one from functioning well or from feeling good.
- is characterized by cycling mood changes. It is also called manic- depressive illness. Bipolar disorder involves cycles of depression and elation or mania. Mania often affects thinking, judgment, and social behavior in ways that cause serious problems and embarrassment. This phase is often a chronic recurring condition.