Neurobiological Findings in Post-traumatic Stress Disorder

Abstract

Studies on mass conflict, torture, or natural disasters have shown that survivors may develop a spectrum of clinical symptoms as a consequence of the experienced traumatic stress. Surprisingly, cross-cultural similarities and consistencies greatly outweigh cultural and ethnic differences. Hence, there must be a common underlying neurobiological basis of post-traumatic stress disorder (PTSD) symptoms. In this chapter, we present a selection of findings on the underlying neurobiology of PTSD and the structure of traumatic memories in particular. The research findings are interpreted within the context of the fear network model, a theoretical model which explains the formation of traumatic memories and has been proven to be helpful to integrate the diverse findings on neurobiological alterations associated with PTSD. We first summarize the most important risk factors for the formation of strong traumatic memories and the onset of PTSD, which are (1) cumulative trauma exposure as the strongest environmental factor and (2) genetic risk as an individual biological factor. This is supplemented by a section on epigenetic modifications, which result from the interaction of the biological-genetic makeup and the sociocultural conditions. We continue by presenting evidence for structural and functional alterations in the brain of survivors with PTSD, which might be either a consequence of the accumulation of traumatic stress or a predisposing risk factor for the disorder. Furthermore, we explain potential underlying molecular mechanisms which might account for the adverse health consequences and premature aging often observed in PTSD. This chapter concludes with a section on the potential reversibility of the adverse physiological effects of trauma by means of successful treatment with trauma-focused therapy and an outlook on neurobiological research on other trauma-related mental health disorders. (PsycINFO Database Record (c) 2016 APA, all rights reserved)