Anxiety and Posttraumatic Stress Disorder in the Context of Human Brain Evolution:A Role for Theory in DSM-V?

Abstract

The “hypervigilance, escape, struggle, tonic immobility” evolutionarily hardwired acute peritraumatic response sequence is important for clinicians to understand. Our commentary supplements the useful article on human tonic immobility (TI) by Marx, Forsyth, Gallup, Fusé and Lexington (2008). A hallmark sign of TI is peritraumatic tachycardia, which others have documented as a major risk factor for subsequent posttraumatic stress disorder (PTSD). TI is evolutionarily highly conserved (uniform across species) and underscores the need for DSM-V planners to consider the inclusion of evolution theory in the reconceptualization of anxiety and PTSD. We discuss the relevance of evolution theory to the DSM-V reconceptualization of acute dissociativeconversion symptoms and of epidemic sociogenic disorder(epidemic “hysteria”). Both are especially in need of attention in light of the increasing threat of terrorism against civilians. We provide other pertinent examples. Finally, evolution theory is not ideology driven (and makes testable predictions regarding etiology in “both directions”). For instance, it predicted the unexpected finding that some disorders conceptualized in DSM-IV-TR as innate phobias are conditioned responses and thus better conceptualized as mild forms of PTSD. Evolution theory may offer a conceptual framework in DSM-V both for treatment and for research on psychopathology.