Addiction is a major social problem that affects not only the person with these problems but also causes harm to family members, for example, by domestic violence, abuse, and neglect. They are often called Affected Family Members (AFMs). While the adverse effects of parental substance use on children have been well-researched, effects on young adults have been studied less extensively. Therefore, in this dissertation, we analyze these effects among a sample of students who were followed for three years using quantitative and longitudinal qualitative methods.