I am susceptible to hypnotism.
On those occasions when I have been hypnotized, it has always felt as though I'm simply choosing to go along with it, allowing my mind to think and act as directed. There remains some part of me that considers itself to be detached, and is consciously making the choice to go with the flow. The extent to which this is actually true, I do not know.
It feels much the same with any other form of altered consciousness. When I'm inebriated or overtired or emotionally offcenter, there is always this kernel - of varying sizes and varying strengths, depending on the nature of the alteration of my consciousness - this kernel of self that sits apart and says "yes, yes, it is good that we should act in this way."
Of course, this might very well be an illusion of the mind. Very often, in retrospect, I find myself regretting the choices that my self has, apparently, chosen to make.
All of this is to say that I don't really know to what extent Max was "playing it up", and I don't think she really does either. The human mind is not neatly compartmentalized, and for all practical intents and purposes, there is little difference between a human being who is intentionally acting in accordance with a disorder they have, and a human being who is a slave to that disorder.