Addiction remains a ‘fuzzy concept’—simultaneously sin, vice, and disease. Drawing on Karen Barad’s concepts of apparatus and agential cuts alongside Annemarie Mol’s framework of ontological politics, we argue that addiction emerges as neither purely biological nor purely social, but as a complex material-discursive phenomenon differentially established across various practices—especially evident in Poland’s semi-peripheral context where global diagnostic categories transform through encounters with local practices and therapeutic traditions. Based on semi-structured interviews with Polish addiction treatment and prevention professionals (N = 30), this study examines how addiction is enacted in therapeutic, diagnostic, and prevention settings. Our analysis reveals how addiction materialises through intra-actions with diagnostic apparatus, becoming coordinated despite persistent tensions, and how professionals’ conceptualisations create boundaries that both stabilise and destabilise addiction’s enactment. The findings highlight addiction’s multiple, emergent nature—professional practices simultaneously maintain its coherence while exposing its fundamental instability as an object of intervention.