The presence of a drug abuser in a family can seriously affect the family's mental health and relationships. This study focuses on the stress of families of drug abusers, relationships, and their relevant factors, as well as examines ways to support them. The subjects of this study were family members of drug abusers treated at drug abuser family support groups, medical institutions, or municipal mental health and welfare centers. To these institutions, 1,298 questionnaires were sent, and 543 responses with sufficient data were used for analysis. The survey consisted of the 12-item General Health Questionnaire (GHQ-12), and questionnaire items regarding disruptions to family life, relationship with drug users, and the use of family support services. The survey results showed that the mean GHQ score was 4.5, and those whose score are cut-off 3 and more, indicating poor mental health accounted for 54.7%. More than half of the subjects responded that drug problems have affected family members in terms of the health condition, daily living, and financial problems. Regarding emotional relationships with the addicts, most of the families answered that they have had negative feelings toward them, such as "being dragged into drug problems" and "being over-protective". A significant correlation was observed between the GHQ score and family members' relationship with the addict, and these variables were closely correlated with participation in the family group, the status of drug abstinence, living environment, and participation in a self-support group by the addict. As the results, most of the family members of drug users have problems with mental health and the recovery of relationships even though they have accessed support centers, and it was verified that the family support group works effectively to help solve their problems.