Complicated grief occupies a contested but increasingly central position in the depth-psychology and bereavement literature, straddling the boundary between normative suffering and clinical disorder. The corpus reveals two principal axes of inquiry: the phenomenological and the diagnostic. O’Connor approaches the term through neuroscience, situating complicated grief—interchangeable in her usage with ‘chronic grieving’—at the severe, prolonged end of a continuous spectrum, affecting approximately one to two in ten bereaved individuals, and distinguishing it neurologically and cognitively from resilient bereavement. Worden’s clinical-psychological framework, by contrast, catalogues complicated grief under the broader rubric of ‘complicated mourning,’ tracing its etiologies through relational variables, personality factors, attachment history, and the nature of the loss itself. A persistent tension in the corpus concerns nosological legitimacy: whether complicated grief constitutes a discrete diagnostic entity separable from depression, anxiety, and PTSD, or whether it is best subsumed under existing trauma categories. Horowitz’s proposal to reframe it as a trauma disorder sits in productive tension with Worden’s preference for grief-specific taxonomy. Both traditions converge on the clinical necessity of naming the phenomenon: without a recognized diagnosis, treatment access and research coherence remain impaired. The term’s instability—cycling through labels such as pathological grief, prolonged grief disorder, and traumatic grief—itself reflects the field’s ongoing negotiation between scientific precision and clinical utility.