Diagnosing a Mood Disorder: Major Depressive Disorder

A 28-year-old female patient presents to the emergency department with severe emotional distress, including persistent sadness, loss of interest in previously enjoyed activities, and feelings of worthlessness. She reports difficulty concentrating, changes in appetite, and sleep disturbances. Her symptoms have been present for over two weeks, significantly impacting her daily functioning. Her medical history is notable for episodes of depression following stressful life events.

Based on the information provided, which of the following diagnoses is most appropriate for this patient?