Which Statement About Bipolar I Disorder Is Accurate

Multiple Choice

Which statement about bipolar I disorder is accurate?

A) The depressive phase is more likely to involve psychotic features than in major depressive disorder.
B) The onset of bipolar symptoms are never associated with seasons of the year as they are in unipolar depression.
C) Single episodes of the disorder are extremely rare.
D) Manic and depressive phases are always separated by lengthy intervals of normal mood.