How the brain structures the boundaries of psychiatric discourse.

Psychiatry has long relied on the brain as both an explanatory model and a source of legitimacy, yet the persistence of this reference cannot be reduced to the progress of neuroscience. This Perspective explores how "brain talk" operates as a metaphorical and organizational device that structures the boundaries of psychiatric discourse. Drawing on the concepts of boundary object and conceptual metaphor, it argues that the brain has served less as a scientific endpoint than as an epistemic anchor enabling psychiatry to maintain coherence amid conceptual fragmentation and uncertainty. As a boundary object, the brain provides a shared referent through which heterogeneous communities (clinicians, researchers, and patients) can coordinate their practices despite divergent interests and languages. As a conceptual metaphor, it generates narratives that render psychiatric knowledge intelligible, productive, and culturally resonant, even when the underlying mechanisms remain opaque. Through this dual role, the cerebral metaphor contributes to psychiatry's self-organization as a pluralistic field grounded in both scientific aspiration and epistemic humility. Thus, finally, this Perspective suggests that the power of brain discourse reveals less about the brain itself than about psychiatry's ongoing effort to stabilize its identity and legitimacy through the metaphors.