Co-dependency can be called an other-addiction.

The other that they are addicted to may or may not be another person. If it is a person, they may or may not be chemically dependent. The co-dependent could be addicted to approval or affirmation of others. They could only be happy if others "make 'them feel happy. They also can be "If-only" addicted. If only XYZ would happen, then they think they will be happy. They are looking for people, things, or circumstances outside of themselves, or how others react to them to bring them happiness.