I spent two years w/a T who was, and being much younger too, I called her "Doctor"

In retrospect, it wasn't a good experience, between the power differential (which she stressed) and her style.

My T now is "just" an LMFT/LPC, so she has a master's and some specialized training. But I think really it's her focus and experience (20 years) plus personality that does the trick, not the titles.