Actually it’s not psychosomatic.
Addicts’ body and brain chemistry has been altered by the drug they abuse. It takes control of them and there’s tons of research on the effects of addiction on the brain.
Psychosomatic would refer to a perceived illness with no basis in biology.
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.