A 27-year-old woman, gravida 2, para 2, comes to the physician to have her staples removed after an elective repeat cesarean delivery. Her pregnancy course was uncomplicated. She states that she is doing well except that since the delivery she has noticed some episodes of sadness and tearfulness. She is eating and sleeping normally and has no strange thoughts or thoughts of hurting herself or others. Physical examination is within normal limits for a patient who is status post cesarean delivery. Which of the following is the most likely diagnosis?
A. Maternity blues
B. Postpartum depression
C. Postpartum mania
D. Postpartum psychosis
E. Poststerilization depression