Question: A nurse practitioner is assessing a patient who describes feeling "emotionally flat" most of the day, every day, for the past two years, with no significant periods of feeling elevated mood. The patient reports a chronic course with poor appetite, low energy, and low self-esteem. Which disorder is most consistent with this presentation? • Bipolar I disorder • Persistent depressive disorder (PDD) • Disruptive mood dysregulation disorder (DMDD) • Major depressive disorder (MDD)