My husband and I were at a friend's house last night. He has the DVD of The Polar Express so I told him about what I had heard. He showed me the parts where the boy is walking on the top of the train, the hobo and the runaway train sequence. None of these events is in the book itself. It's a beautifully done movie. Although those parts didn't cause me to experience anxiety our friend agrees that the movie causes him to feel very much that way.