I agree with that statement; during an inpatient stay, the in-house pdoc diagnosed me as mixed when I was actually having very distinct fluctuations daily for about a month. Not all of them seem to want to acknowledge how differently bipolar can present itself.

I, too, can sometimes get very emotional or reactive to my environment depending on my mood, but in the past I've also become emotionally flat for months or years in response to inner turmoil and chronic stress.

When we're exposed to these stresses and triggers over many years, I think our threshold and tolerance before experiencing a strong reaction is lowered greatly. The association between emotional sensitivity and borderline is really quite baseless. I thought I had it once, but it seems to be more about your social functioning and self image.