Excellent article, Gabyunbound. I've always been a little perplexed why they confuse people, because they really are quite different. I think a lot of it stems from the word "mood". Like in BPD, it's a transient reactive emotional thing, whereas in BP it's more a sustained state of being. But people don't tend to think about the range of meaning it can have.

He covered a lot of good points like stable periods vs a constant situation.

Thanks for recommending it.