The World Health Organization's classification system defines "a manic episode" as one where mood is higher than the person's situation warrants and may vary from relaxed high spirits to barely controllable exuberance, is accompanied by hyperactivity, a compulsion to speak, a reduced sleep requirement, difficulty sustaining attention and/or often increased distractibility. Frequently, confidence and self-esteem are excessively enlarged, and grand, extravagant ideas are expressed. Behavior that is out-of-character and risky, foolish or inappropriate may result from a loss of normal social restraint.