Questions: What does rapid cycling mean?
Answers: Rapid cycling means that someone diagnosed with bipolar disorder (or depression) experiences four or more episodes of depression and/or mania in one year. 
   Rapid cycling can happen any time someone experiences bipolar disorder—about 10-20% of people diagnosed with bipolar disorder experience rapid cycling at some point. In many cases, rapid cycling eventually goes away on its own and people return to a pattern of longer and less frequent episodes.