It is a disorder in which a person feels unhappy but at the same time feels full of vitality, freshness, and is very active. Mood swings are another name for this type of disorder. The fact that the condition manifests itself at two opposite extremes of a person's emotional nature gives rise to its name, bipolar disorder. Those who are depressed cannot participate in any activities because they spend the entire day feeling miserable and have no interest in doing anything.