I don't think anyone with any type of personality should dampen your spirit, maybe put it on alert, but dampen noOoo. If their spirit has dampening zones or is repulsive, ignore them. Before long I'm quite sure they won't be content knowing that they have no company to share whatever misery. So they'll either change or relocate to profitable territory. lol
They kind of bring me down, because it can be pretty exhausting talking to someone who is always bubbly, energetic, talkative, etc. If someone is a bit more mellow, its easier to talk and not get buried under the other person's excitement.
Do they? Absolutely YES. I have lived with some people of those kind (not that I'm not one of them as sometimes I could be) and it's difficult especially if you live in the same roof. But should they? It's always an issue of interior disposition. When one is properly disposed interiorly, I believe that nobody could even shake the person or define him/her with such type of personality.