Abstract

Post-traumatic stress disorder (PTSD) is a severe mental disorder described only by operational criteria, without a proper dialectic essential analysis. In this study, we present a typical PTSD case with psychotic features, describing his living world through the domains of Heideggerian ontological-existential constituents –spatiality, temporality, corporeity and interpersonality (being-with-others). A phenomenological reduction and diagnostic elaboration was then performed. An essence of pervasive fear, that locks all intentionality and taints the entire being-in-the-world is described as the main characteristic of PTSD. The differential diagnosis is then discussed through a temporal perspective, showing essential differences among Bipolar Disorder, Schizophrenia and Persistent Delusional Disorder. We stand for a return to phenomenology, and its use to diagnosis and disorder description as a way to improve diagnostic validity and reliability.