A 32-year-old man from Bangalore is referred to psychiatry by his general practitioner. Over the past 4 days, he has experienced a distinct period of elevated mood, increased talkativeness, and heightened creativity (writing poetry and composing music). He reports needing only 4–5 hours of sleep per night but does not feel tired. He started a new hobby (painting) with intense focus but has not neglected his job or family responsibilities. He denies any grandiose beliefs, risky financial decisions, or sexual indiscretions. His past psychiatric history includes two major depressive episodes (each lasting 3 months), treated with fluoxetine. He has never experienced a full manic episode. Mental status examination shows elevated mood, increased rate of speech, and normal insight. What is the most likely diagnosis?