ALICIA: What's wrong with him?
DR. ROSEN: John has schizophrenia. People with this disorder are often paranoid.
ALICIA: But…but his work, he deals with conspiracies, so…
DR. ROSEN: Yes, yes, I know. In John's world, these behaviors are accepted, encouraged. As such, his illness may have gone untreated far longer than is typical.
ALICIA: What do you mean? How long?
DR. ROSEN: Possibly since graduate school. At least, that's when his hallucinations seem to have begun.
Alicia and Dr. Rosen have this exchange right after John has been institutionalized for schizophrenia. As you can see, Alicia had not suspected that anything was up. She had even believed John when he told her stories about people she had never met, and who turned out not to be real.