i read an interesting research article a few days ago (would post a link, but you'd have to pay to read it. It was free for me through my university's subscription) on mood lability in bipolar II. Apparently, the researchers discovered that frequent mood swings could be used as a screening test for bipolar II in people with depression.

Subjects with BP II and unipolar MDD were asked whether these statements applied to them:
1. "My mood often changes from happiness to sadness without my knowing why."
2."I have frequent ups and downs in mood, with and without apparent cause."

Those with BP II were significantly more likely to admit to frequent mood swings. People with BPD were excluded from the study (because mood lability is already a well-known symptom of that disorder) so the rapid mood changes in the BP II subjects were not due to co-morbid borderline disorder.

I feel that this study explains a lot. Looking across the last several years, I have periods of several months when I was mostly depressed, other periods when I had more energy and was very productive and confident, and still other periods when I was somewhere in the middle. This seems like classic, slow-cycling bipolar.

BUT, if you "zoom in" on any given period of mood, you'll find moments, days, even weeks of symptoms of the opposite mood blended in. Zoom in even further, sometimes, and you'll see me switch from up to down to up again within a five minute span! This had really confused me: do I have a mostly ultradian, ultra rapid, rapid, or slow cycling pattern?!? I have cycles on top of cycles!
And apparently, this is normal.
Does anyone else find that they have mood swings within their normal cycling pattern?