Post-traumatic stress disorder (PTSD) represents a transcultural recurrent response to extreme events, documented across approximately four millennia of human history. Although formally codified in Diagnostic and Statistical Manual of Mental Disorders (DSM)-III (1980), descriptions of post-traumatic symptomatology already appear in Mesopotamian cuneiform texts (2027–2003 BCE) and continue through classical literature and modern clinical observation. This historical–critical analysis assesses the phenomenological continuity of trauma-related symptoms across epochs and cultures, reconstructing the evolution of aetiological interpretations from moral condemnation to medical and neurobiological recognition. Through a critical reading of historical, medical and literary sources, International Classification of Diseases (ICD)-11 and DSM-5-TR criteria are employed as heuristic descriptors to organise symptom language across periods, without implying retrospective diagnosis or strict nosographic equivalence. Core symptom domains display notable stability across military, civilian and childhood trauma contexts. Three paradigmatic shifts emerge: from moral to organic interpretations (1600–1900), from organic to psychodynamic understanding (1876–1920) and from military-specific recognition to a universal framework (1915–1980), with wars acting as accelerators of clinical conceptualisation and medicalisation. This research suggests that the divergence between the granularity of the DSM-5-TR and the parsimony of the ICD-11 is best interpreted as complementary operational strategies that, through a dialogical use of historical materials, can both inform and critically interrogate the contemporary nosology of PTSD. The contemporary challenge is to develop integrative models that honour both the universality of vulnerability and the uniqueness of each traumatic experience, while maintaining vigilance against restigmatisation. Overall, recognising trauma’s historical continuity may inform current clinical practice and contribute to stigma reduction.