Yeh, I don't think it's specific to anyone really. Certain people seem more receptive to the placebo effect, but, I find it hard to see how there could any be any objective test to see if some people are more receptive than others.
If you had two depressed people, and you gave the singer some sugar tablets and he felt ok, and gave the bassist a brand new (what's in fashion these days?) Wal and he didn't feel much better, or he felt 100 times better, you couldn't really make a judgement either way.
I don't know if i'm making sense, but i'd like to know if there are any tests/studies that have been or can be done to see the responsiveness of people to the placebo effect, and whether the results of this would suggest different responses from different "groups" of people.