Sophie Turner, famous for her role as Sansa Stark in the fantasy series Game of Thrones, says she had to read up on schizophrenia and mental disorders so as to prepare for her role in X-Men: Dark Phoenix. The actor, who debuted as Jean Grey in X-Men: Apocalypse, was provided with study material by director Simon Kinberg. 

"As soon as Simon told me what the film was about we started sharing ideas and materials. He gave me a big, big book on schizophrenia too. Also, I found this video online which kept repeating what it sounds like being a schizophrenic. So I used to walk around town with all these voices in my head to see what it actually felt like," she says, adding that she wanted to understand the complexity of her character. "Jean is just so, so, layered. She's so complex in X-Men: Dark Phoenix. I really don't think that I've done more research for a role than for this one and I loved every minute of it."