A 67-year-old man presents for a follow-up evaluation. He was diagnosed with Huntington disease six months ago. Over the past two months he developed depressive symptoms and was diagnosed with major depressive disorder one month ago. The depressive symptoms have caused severe impairment in his social functioning. Which of the following would be most consistent with a diagnosis of depressive disorder due to another medical condition?
A. Concurrent features of mania or hypomania
B. Depressive symptoms resulting from the psychological stress of a medical condition
C. Pending diagnosis of Huntington disease
D. The depressive symptoms are not better explained by another mental disorder