Aim: Family members' lives and health are seriously affected by alcohol-and drug addiction in close relationships, and research on addiction treatment shows that outcome of treatment is better when family is involved, both for the patient and family member. In Norway, there are clear political and professional guidelines in favour of involvement of family/significant others in the course of treatment, however, there are few addiction treatment services in Norway who comprehensively do so. The aim of this study is to explore therapists' experiences from involving family and significant others in interdisciplinary specialised addiction treatment (TSB), within an inpatient clinic in Norway. The research question is: What significance do therapists emphasise from