"Psychological addiction isn't controversial at all .It's quite well established that it both occurs and affects different people in different ways and to different degrees. The difficulty -because it's subjective- is putting numbers on it."
It is controversial in psychology, not because psychological dependence doesn't exist or isn't a serious problem but because co-opting the term which always applied previously to a physical dependence upon a chemical substance to apply to mental dependence you;
1) confuse the general public & give the tabloids more ammunition to spread disinformation and outrage.
2) You muddy the waters for treatment of both.
This is why it is controversial because it is constantly being debated in psychology research. Ultimately at the lowest level you could probably argue that a psychological addiction ends up having a chemical basis due to our internal reward mechanism, but I am firmly on the side that using the term addiction for both conditions does no-one any favours especially when most people prefer simple but wrong over complex but true.
I am all for vaping, I switched to vaping two years ago and quite vaping last year.
But when people start thinking that quitting nicotine is just the same as quitting chocolate or coffee it helps no one.
The way modern language is going, we seem to be heading backwards. Words are becoming more general and less specific. I think we'll all be just grunting again pretty soon