Reading as an addiction

Great quote from Diane Setterfield in the back of her book The Thirteenth Tale. (see my review) Setterfield is answering the question:
Margaret says on page 4 that reading can be dangerous. In what ways do you think that is true, besides falling off of stone walls while wrapped in a story?

an excerpt of Setterfield's answer:
... about whether reading could be considered an addiction. It is, after all, mind altering. (I'd be interested to know what what happens inside the brain, chemically and structurally, when someone reads. It might shed light on the reading addiction question.) I know there are people who don't read fiction at all and I find it hard to understand how they can bear to be inside the same head all the time. ... I find it so soothing to have another mind I can just hop into by opening a book. In fact if I have to get a train and I don't have enough reading with me, I can feel quite panicky. So am I addicted? And is it dangerous?
...
Is reading dangerous? I don't know. But I know one thing that is always dangerous, and that is not living. So I resist the lure of the kitchen/library. For now, at least.