Henderson, Craig2022-08-242022-08-242020-082020-08-01August 202https://hdl.handle.net/20.500.11875/3636Over 2 million people in the United States have an opioid use disorder (OUD) (Alderks, 2017). However, only 19% of people with an OUD in the U.S. are in medication-assisted treatment, such as methadone maintenance treatment (MMT; SAMHSA, 2018). A drawback of MMT is the effort and motivation required from opioid users to engage in this form of treatment. The theory of self-determination posits that the basic needs driving motivation are relatedness, competence, and autonomy (Deci & Ryan, 1985; Deci & Ryan, 2000). Self-determination theory (SDT) has been applied to addiction in previous research (Groshkova, 2010; Kennedy & George, 2009; Simoneau & Bergeron, 2003), but has rarely been applied to the population of MMT patients (Zeldman et al., 2004; Groshkova, 2010). The objective of this study was to examine the association of relatedness (conceptualized as perceived social support), competence (conceptualized as self-efficacy), and autonomy (conceptualized as autonomous functioning) with treatment engagement (conceptualized as treatment attendance) and number of positive drug screenings in individuals receiving MMT for opioid dependence. It was expected that the relation between perceived social support and substance use-related outcomes would be explained in part by increased feelings of autonomous functioning and increased self-efficacy. Results of the present study suggest that increased relatedness to others indirectly decreases the positive drug screenings one has in methadone treatment by way of increasing feelings of autonomy.application/pdfenPsychology, GeneralThesis2022-08-24