Trivia

Her research indicated that in 2009 most people with the disease were either misdiagnosed or undiagnosed. Cahalan was fortunate to be correctly diagnosed because, according to Najjar's estimates, only 10 percent of people with the disease were properly diagnosed at that time. Since then, a better understanding of the disease and its symptoms has resulted in more frequent diagnosis and treatment.

Dakota Fanning was originally cast in the lead role.

Charlize Theron was cast in a role, but she dropped out. However, she remained on as a producer.

In May 2014, it was announced that the book was being adapted into a film of the same name starring Chloë Grace Moretz and produced by Cahalan and Charlize Theron. The film was released on Netflix June 22, 2018.