Withdrawal has a basis in biology. An active alcoholic, for example, can actually die from suddenly stopping for a day.
I believe psychosomatic includes conditions made worse by mental factors. So, while a smoker won’t die from not smoking, they may be sweaty and shaky for awhile.
Nevertheless, you may be right that addiction is not technically characterized as psychosomatic by doctors. What I meant by that word was the perception of the addiction from the addict’s point of view.
The lack of the comprehension from the non-addicts point of view is the underlying cause of their hostility towards addicts, to which the author of the article is definitely in that camp.
Watching an addict prioritize their fix over all else is painful to watch when it’s someone you care about.
I've heard it put this way...
You and I have lots to worry about in a day: Getting the kids to school, meeting that deadline, getting new tires for the car, checking on mom, remembering to send the mortgage payment, and a thousand other concerns.
The addict only has one problem in life: Where to get that next fix.