Despite the global impact of substance misuse, there are inadequate levels of specialist service provision and continued difficulties with treatment engagement. Within policy and research, there is substantial consideration of the importance of these factors. However, there is little empirical evidence of the views of non-treatment-seeking substance users, who make up the majority of the substance using population. The aim of this study was to understand how these individuals make sense of their behaviour and their reasons for not accessing treatment. A constructivist grounded theory approach was used to interview eight individuals who were currently using substances and not seeking help to stop. The analysis highlighted the importance of attachment to an identity associated with substance use, and relational variables such as connectedness to others, for treatment decisions for individuals who use substances. Understanding these influences, through trauma- and attachment-informed service provision, may reduce barriers to help-seeking and improve treatment uptake.