For the previous six weeks or so, Carlton's co-workers have noticed that he has seemed very sad much of the time. He has also stopped going to team lunches and stays in his office on his own far more than usual. However, in the last few days, he has seemed very different. He has been in an excited state much of the time, talking more rapidly than usual, and many of his ideas at team meetings seem unrealistic and overambitious. Which of the following disorders are Carlton's symptoms most consistent with? a. dysthymia
b. major depression
c. bipolar disorder
d. schizophrenia