Unity in a family is hard to orchestrate, especially where addiction is present. Sometimes this is because parents are elderly or a family member is too angry, or too overwhelmed to take in new information. But this shouldn't stop a family member from taking steps to guide their loved one toward treatment.
While DBT was originally designed for people with suicidal tendencies, it is effective for a host of conditions. DBT is typically taught in groups plus individual therapy. The creator of DBT, Marsha Linehan, provides a directory of practitioners trained by her institute.