Psychological coherence occupies a pivotal position in the depth-psychology corpus, functioning simultaneously as a developmental achievement, a clinical target, and a theoretical organizing principle. Across the literature, coherence is consistently distinguished from mere cohesion: where cohesion denotes the synchronic sticking-together of mental contents within a given state, coherence describes the diachronic integration of distinct self-states across time. Daniel Siegel stands as the preeminent systematic voice, situating coherence within a neurobiological framework wherein integration — the linkage of differentiated elements — is identified as the fundamental mechanism of mental health. On this account, the breakdown of integration constitutes the pathological core of dissociation, trauma sequelae, and disorganized attachment. Heller and the somatic tradition extend this argument downward, insisting that narrative coherence is always a surface reflection of somatic coherence, and that healing must be bidirectional. Van der Hart and collaborators frame coherence as the achievement of synthesis — an ongoing, effortful mental action vulnerable to disruption when mental level falls under stress. McGilchrist introduces a critical epistemological counterweight, noting that coherence as a criterion of truth is insufficient and potentially self-sealing. Bowlby’s attachment lineage traces narrative coherence to early relational experience, connecting the parent’s autobiographical fluency to the child’s later integrative capacity. Together these voices establish a field of productive tension: coherence as health-ideal, coherence as developmental inheritance, and coherence as epistemological risk.