People with DPD unable to be or fully function alone and make independent decision and they fully depend on other people. It’s a mental illness

Codependency is something people might develop with one person, like romantic partner but they are able to be independent and functioning fine on their own in other aspects of life,. It’s not a mental illness. People with alcoholic parents are often codependent in their romantic relationship

Also codependents focus on pleasing others while I don’t think people with DPD worry about pleasing others, they just have hard time figuring life out independently without depending on others. I think good therapy should be helpful in both cases