Originally Posted by Within
Addiction is the continued use of a mood altering substance or behaviour despite adverse consequences...
If something is 'psychologically' addicting it can have just as bad, or worse, consequences for its user/abuser. Besides, if something becomes 'psychologically' addicting, chanced are physiological changes are taking place somewhere, it's just that we don't understand it, or can't 'see' it.
We really understand very little about the mechanism of addiction. Wouldn't you agree?