The Insanity of Denethor

[Essex]

Yes it does, but I always enjoy finding lines in the book that Jackson uses as an excuse to add something in. Gandalf's 'striking' of Denethor being one and, for example, a paragraph from TT in that it was stated

Out of the darkness arrows whistled. Swiftly a scout rode back and reported that wolf-riders were abroad in the valley, and that a host of Orcs and wild men were hurrying southward from the Fords of Isen and seemed to be making for Helm's Deep.

and so he adds in the whole Warg Rider scene.