I think I have experienced "ultra ultra rapid cycling" a few times a number of years ago, but only for a handful of days (not usually consecutive days) max. It wasn't common in my bipolar, like others say it is for them. A couple of years I had rapid cycling, but only as 4 or 5 separate episodes in a year. Not ultra ultra rapid cycling's multiple episodes in a day. I did very often experience what used to be called "mixed episodes", where I experienced some depressive symptoms with manic symptoms simultaneously. That, to me, was what a mixed episode was. Not ultra ultra rapid cycling.

When the term "mixed episode" disappeared from the new DSM (DSM-5) and the new use of a "with mixed features" specifier was created, it became easier for me to understand some of my past episodes previously called "mixed episodes". Some of you probably already know how they use the new specifiers, like "with mixed features". If you do, ignore the below explanation. For anyone that doesn't, they identify the episode that is dominant (e.g. the episode with the most symptoms represented) and then add the "with mixed features" specifier if some (but not as many) symptoms of another episode are represented. For example:

*Depressive episode with mixed features (meaning some hypomanic or manic)
*Hypomanic episode with mixed features (meaning only some depressed)
*Manic episode with mixed features (meaning only some depressed)

There is no situation where manic symptoms would be mixed features of hypomanic, and vice versa. Certainly if one went from hypomanic to full blown manic, the diagnosis could switch what was initially considered depressive episode with mixed features to manic episode with mixed features, if the manic symptoms began to outnumber or be dominant over the depressed symptoms.

In the DSM-5, if there are seemingly an equal number of manic symptoms as depressive symptoms (with neither seemingly dominant), they will call it a manic episode with mixed features. Or equal number of hypomanic as depressive (with neither dominant), it is depressive episode with mixed features.

I am pretty sure I have experienced all of the three primary "with mixed features" episode types above in the past. They obviously felt and presented a bit differently because of the leaning in a dominant direction. Like when I had depression with mixed features, I might have lacked the disinhibition, grandiosity,goal-directed activity, distractability, or pressure talking that comes with hypomania or mania, but I might have had all or almost all of the depressive symptoms, but with decreased need for sleep, racing thoughts, and agitation. Sometimes I even lacked the energy of hypomania or mania in such cases.

When I had manic episodes with mixed features, I had almost all manic symptoms except elation and perhaps grandiosity, but felt hopeless and desperate, lack of interest in things, worthless, and maybe suicidal or prone to self-harm. I did not have the fatigue or diminished ability to think (I had racing thoughts instead), wasn't in bed all day, and may still be productive in a frantic manic kind of way, but with distress.

For me, both of the above episodes w/mixed features were horrible and potentially dangerous. I think, for me, the manic episodes w/mixed features were a bit more dangerous. I had the extra manic disinhibition to make harmful attempts and actions more likely. I, personally, had more psychosis when the mania was dominant w/mixed features.

An interesting thing that has changed is that the DSM-5 allows for hypomania w/mixed features and depression with mixed features to be part of Bipolar type 2. In the past, the DSM stated that any mixed episodes would automatically mean a Bipolar 1 diagnosis. From what I have read, many psychiatrists (but not all) ignored that rule if they had never seen or had evidence/history of symptoms sufficiently severe to be considered full-blown manic.

Sorry if this was an unsolicited long explanation, but I felt compelled to offer it since the former "mixed episodes" did not necessarily look the same in me at all times.

I had a psychologist friend who was adamant at referring to mild-moderate mood cycling within a day as "mood lability" and not ultra ultra rapid cycling. I think she was from a school of thought that sort of rejected the idea of such extremely rapid cycling. She said that "mood lability" is common in bipolar disorder and represents mood issues that don't meet the full criteria for any given episode (like 4 days or more for hypomania, 1 week or more for mania, or 2 weeks or more for depression, unless hospitalization is required).

As an aside, in addition to there now being a "with mixed features" specifier in the DSM-5, there are the following other specifiers that can be added to an episode type: "with anxious distress", "with rapid cycling", "with melancholic features", "with atypical features", "with mood-congruent psychotic features", "with mood-incongruent psychotic features", "with catatonia", "with peripartum onset", and "with seasonal pattern".