Codependency is a disease that distinguishes itself by a form of immaturity that is caused by a youth trauma. Codependency is the underlying layer of addiction. Someone with codependency issues can be recognised by the behaviour of someone that has an inappropriate interest for the problems of others, not necessarily in the context of addiction.
A codependent person can be in distress from trying to change themselves or feel shame over their own thoughts and feelings that are in conflict with the problems of another.