I don't have any addictions excluding cigarettes (damn why did they have to ban proper cloves here in the States? :grumblesnazzlefrass: DON'T SMOKE KIDS!), and I don't have any compulsive disorders - what I do have is a thing with my brain wiring being all off. A sort of learning disability - but while I will go into the machine writing mode, I am capable of doing other things at the same time. Usually I'm on the phone or taking to someone face to face - and the conversation may, or may not have anything to do with what I'm writing, and there's several trains of thought plotting out things that don't have anything to do with the writing at all.
Dysgraphia/agraphia - it causes the body a hard time with fine motor skills (which is weird as I play several instruments...) but I can't hold a pen very well at all as an example. It's been hypotosized by one of my old psych profs (and my husband also believes this) that my brain went and made up for that mis-wiring in my head, giving me multitasking skills when it comes to thought processes. I'm not happy unless I'm doing a minimum of two things at once - if I don't, then I can't superfocus on the main item and get out whatever needs to come out.
While I'll definitely ignore all my body's needs in that state though, I don't seem to ignore other things that need to be done by and large....