(1) The harm-reduction benefits of opioid agonist treatment (OAT) are well-established; however, the UK government's emphasis on "recovery" may be contributing to a high proportion of people leaving treatment and low retention rates. We wanted to develop a rich and nuanced understanding of the factors that might influence the treatment journeys of people who use OAT. (2) We explored factors at each level of the socioecological system and considered the ways these interact to influence treatment journeys in OAT. We carried out semi-structured interviews with people who use OAT (n = 12) and service providers (n = 13) and analysed data using reflexive thematic analysis. (3) We developed three themes representing participant perceptions of treatment journeys in OAT. These were: (1) The System is Broken; (2) Power Struggles; and (3) Filling the Void. (4) Conclusions: The data suggest that prioritisation of treatment retention is important to preserve the harm-reduction benefits of OAT. Stigma is a systemic issue which presents multiple barriers to people who use OAT living fulfilling lives. There is an urgent need to develop targeted interventions to address stigma towards people who use OAT.
Keywords: drug treatment; methadone; opioid agonist treatment; qualitative; socioecological model; stigma.