There are some who see co-dependency underlying any addict's core issues. If you define it solely in the older and more narrow way -- needing to take care of others, enabling others' addictions, putting your own needs last -- then it doesn't seem to apply.
But if you look at co-dependency as a need to rely on external sources, which includes the approval of others as well as substances, to feed a low self-esteem and value, then it does start to apply much more broadly.
I've become inclined to see it as the latter. I've known several addicts who are hyper sensitive, very reactive to, and extremely dependent on others' views of them and need to feel validated constantly by others.
best
gf