Diminished responses to external threat as a possible link between chronic/severe posttraumatic stress disorder and suicide

Abstract

Objective: Posttraumatic stress disorder (PTSD) is linked with suicide attempt history, but the neurobehavioral mechanisms explaining this association are unclear. The narrative review presented here proposes that blunted neurobehavioral responses to acute external threat represent one pathway via which chronic, severe, and/or multitrauma PTSD may increase risk for a suicide attempt among those with suicidal desire.

Method: A brief review of theoretical perspectives on diminished responding to external threats in suicide and PTSD is provided (Part 1) followed by the presentation of existing evidence using neurophysiological (Part 2), startle reflex and autonomic (Part 3), and behavioral (Part 4) measures of threat reactivity among individuals with past suicide attempts and PTSD.

Results: Findings generally support the proposal that blunted neurobehavioral responses to threat may link chronic and severe PTSD with suicide, though more evidence from all levels of analysis is needed. Additional questions also remain, including the relative influences of multiple traumatic events and PTSD severity as well as the directionality of the associations among PTSD, suicide, and blunted threat responses.

Conclusions: Blunted neurobehavioral responses to external threats appear to be one plausible mechanism via which chronic, severe, and/or multitrauma PTSD may elevate risk for a suicide attempt when combined with suicidal desire. Future research should seek to use intensive longitudinal designs to evaluate the directionality of relations between PTSD, suicide, and threat reactivity across multiple levels of analysis, including the behavioral freeze response. (PsycInfo Database Record (c) 2021 APA, all rights reserved).