In response to Rack,
As you say it's true most actors don't have multiple personas, if one did study Depp and all his TV interviews - very interesting! You see I have this fascination with Andy Kaufman, Crispin Glover, David Byrne, David has been diagnosed as AS and Andy is so AS. From what I notice, this is with myself also, is there are subtle intellectualisms in choice of the voice mainly, body language is not natural it's improvised, I believe that persona comes together through the perception of the person and what their mood is at the time when they take into account who's interviewing them, what clothes and appearance they are wearing themselves, the type of show, it's every TV appearance persona is 'cooked' intellectually and acted out as they desire, sometimes to fool and intrigue, sometimes just to get through the interview!
I believe some Aspies are the real actors - the best actors, it's like their whole life is a film, everything is a stage, there is no real them to find amongst the acting, it's evident with Andy Kaufman there is no real him, he is/was a child - who learnt to act like an adult, he mimiced he acted his whole life