A 40-year-old man reports 1 week of increased activity associated with an elevated mood, a decreased need for sleep, and inflated self-esteem. Although the man does not object to his current state (“I’m getting a lot of work done!”), he is concerned because he recalls a similar episode 10 years ago during which he began to make imprudent business decisions that resulted in bankruptcy. A physical examination and laboratory work are unrevealing for any medical cause of his symptoms. He had taken medication for a major depressive episode but self-discontinued it 3 months ago because he felt that his mood was stable.