Good watch, probably won't watch again, but can recommend.
SEIZURE WARNING: Movie contains more than one scene of intense flashes. Honestly made me nauseated.
Christina Ricci greatly carries this movie, and they certainly needed a strong actress to play crazy as required for this script, and she does amazingly well.
You can certainly feel the atmosphere of uncertainty in the movie as well as the shift from it being about her mental well-being to general conspiracy theory craziness. John Cusack steps in with some good support in that regard, adding as many questions as answers.