Ernest Is Deeply Sad

Ernest is deeply sad. He does not eat much, doesn't seem to want to take care of himself, and believes his life's work is useless. You think this is strange because several weeks ago Ernest was very excited about his life. He talked and talked about his new book and even seemed to stay up an entire week writing. Ernest probably has

A) major depression.
B) schizophrenia.
C) obsessive-compulsive disorder.
D) bipolar disorder.