Hi fern. I never owned the DSM-IV or earlier versions, but I do own the DSM 5. "Ultradian cycling" is not written there unless I have really overlooked it. What is mentioned is "with rapid cycling", as a specifier. It's my assumption that when that specifier is used, it likely refers to any form of rapid cycling meaning "four or more episodes in a year". There is certainly confusion in that the DSM 5 only labels a mood episode as one meeting certain time and symptom criteria. I am not 100% sure of this, but if one had significant mood shifts (as you mentioned) and they were present for days in a row and included sufficient symptoms, then maybe that could qualify as an episode????? If so, then it would clearly be up to the psychiatrist how to label it (what type of episode and specifier).

I do believe that people with bipolar disorder have mood lability not necessarily qualifying as any episode. That's known in many circles. As for anyone having mood shifts during the day that aren't "bipolar-related", sure. Fern's point is definitely valid. Regular folks don't usually feel fatigued and suicidal in the morning and elated and ultra high energy in the afternoon for no really major reason. How do us folks with bipolar disorder really know where the limits are unless we've truly learned what stability is. I think I know what regular "non bipolar" mood shifts are. I think Fern does, too. I also know what I regard as "mood lability" that is still outside the norm. This term also apples to the major drastic shifts that people with borderline personality disorder experience, but they don't own the term exclusively. That disorder has almost mandatory dx criteria that most people with bipolar disorder never meet.

For anyone interested in this topic, Dr. Phelps goes into it well. For those who want to read it but bypass my blog post, find the relevant page on Dr. Phelps' site at
Rapid Cycling And Mixed States As "Waves" - PsychEducation