New York Times article about “The Amy Adams Method” of playing Gillian Flynn protagonist in TV mini-series raises question of multiple personality in actors

In my post earlier today, prompted by an article in The New York Times—

https://www.nytimes.com/2018/06/29/arts/television/amy-adams-hollywood-sharp-objects.html—I focused on the multiple personality of protagonists in Gillian Flynn’s novels. But the New York Times article is primarily about an actress, Amy Adams, and acting.

The article mentions that the actress had “an attendant ‘negative self-dialogue’ that never quite went away. ‘I have this internal voice that is just not a cheerleader for myself’ she said.” (She may be describing the voice of, and dialogue with, a critical alternate personality.)

“Ms. Flynn said that…Ms. Adams ‘completely immersed herself physically, bodily, mentally into Camille’ [Flynn’s protagonist in “Sharp Objects”]. [The director added:] ‘I noticed her voice dropped a few notes and her way of walking changed…’ ”

[The article goes on to explain:] “To create a believable performance, many actors jettison their own personality, hoping their character will seize the resulting void like a territorial spirit. During the making of ‘Lincoln,’ Daniel Day-Lewis was so thoroughly consumed by his presidential portrayal that Sally Field, who played Mary Todd Lincoln in the film, later claimed she’s ‘never met him.’

“Some have noted that most method actors…take pride in burying themselves in work…‘Oh, my gosh, the demons they must take on!’ Ms. Flynn said.” (Her mocking metaphor of demon possession is an old theory to explain multiple personality.)

The above, commonly made remarks about actors and acting, make actors seem like a group that might have a high percentage with multiple personality, like fiction writers. So I have often been tempted to write about actors, but compared to writers, actors have very little written either by or about them.