A 24-year-old man presents with mood swings every 2-3 weeks…
A 24-year-old man presents with mood swings every 2-3 weeks over the past 15 months. He describes periods lasting about 2 days of feeling “energized,” sleeping less, and spending impulsively, followed by episodes of low mood, fatigue, and withdrawal for a few days. He cannot recall if these episodes caused significant impairment, and no episode has clearly met full criteria for mania or major depression. There is no history of psychosis, hospitalization, or suicidal ideation. Based on this presentation, which of the following is the most appropriate diagnosis?