Carleen comes to therapy because she is feeling sad. carleen says her she has often had periods of extreme sadness in the past and they typically last between 6 and 8 months. during those times she overeats, has trouble sleeping, feels exhausted all the time, and thinks a lot about dying. at other times, however, carleen says she feels wonderful. during those times, which last about a week, she gets a lot done, feels as if she could do anything, talks a lot and quickly, doesnt sleep, but doesnt feel tired. carleen says her up times are great and have never caused her any trouble. carleens most likely diagnosis is:
a. major depressive disorder
b. dysthymia
c. bipolar i
d. bipolar ii