The purpose of this paper was to investigate people’s motivations for making the decision to stop doing drugs or drinking alcohol and seek treatment for their substance abuse and/or alcohol abuse. The purpose was also to investigate how they manage to maintain the changes after they’ve received treatment. This was done through a literature review of previous research from the last fifteen years. A total of nine articles was chosen and the results of these articles has been analyzed through the theory called self-determination theory by Richard Ryan and Edward L. Deci. The results show complex processes where many factors are contributing to people’s motivation to change and maintain the change. Themes created in the analysis are named external regulation (sub-themes: legal system, had enough), internalized regulation (sub-themes: identity, health, occupation/accommodation), relatedness and autonomy. The main conclusions of this study are that it is an internalization of external motivations that enable people to make a change. There are some general factors found in all the studies that affect their motivations. However, common factors at an overall level can have different meanings at an individual level. The different factors weigh differently for different people and the meaning can also change during different parts of the process.