while addictions can be both chemical and psychological, diapers are definitetly psychological. And IMHO that makes them a lot nicer to have.
I feel that anything can be an addiction. I consider myself someone with an addictive personality, and I'm constantly "checking" myself to make sure I don't go overboard with whatever my 'collection of the season' is.
If the money that someone spends on diapers and related supplies results in them not being able to pay the bills for the month, or if it's getting in the way of being able to go to work, for example, then it would be worth taking a step back and looking at the big picture. This threshold will matter from person to person, of course.
/me looks in his diaper cabinet and closet and wonders.... (I actually added it up today, I have 99 unopened bags of various types)
I'd love to see a pic of that.
It doesn't seem like addiction to me in theory or practice. The desire came from inside me with no conscious memory of having worn them. It's a sensual, sexual, status thing, not something I was introduced to that became a compulsive habit. Even now that I wear frequently (24/7 again at the moment), I don't see it as an addiction but something added that I enjoy. I've gone without for long stretches but they wind up being appealing again sooner or later.