Someone who cares for another person who is perfectly able to care for themselves, but chooses not to, is a Co-Dependent.

Co-dependents are drawn to addicts like moths to a light bulb at night. They need to be needed. They need to fix things. They need to be in control of things and make them better.

Co-dependents usually think that they are "friends, a good parent, a good spouse, a good boyfriend or girlfriend". Not so. They may be lots of other things; like victims of abuse, and like suckers, and all, but they are clearly not "friends".