Emotional Memory in Post-traumatic Stress Disorder: A Systematic PRISMA Review of Controlled Studies.

Florence Durand,Clémence Isaac,Dominique Januel

doi:10.3389/fpsyg.2019.00303

Abstract

Background: Emotional memory is an adaptive process that improves the memorization of emotional events or stimuli. In Post-Traumatic Stress Disorder (PTSD), emotional memory may be altered, which in turn may affect symptoms. Having a clearer view of the processes of interaction between memory and emotional stimuli in PTSD may improve our knowledge of this disorder, and could create new therapeutic management tools. Thus, we performed a systematic review of the evidence of specific emotional memory in PTSD patients.Method: Following PRISMA guidelines, a systematic review of MEDLINE, PsycInfo, and ScienceDirect was undertaken to identify controlled studies on emotional memory that used cognitive tasks on PTSD patients. The initial research was conducted from June 2017 to July 2017, and search terms included: Post-Traumatic Stress Disorder; PTSD; emotional memory; emotion; emotional; memory; and episodic memory.Results: Eighteen studies reporting on 387 PTSD patients met the eligibility criteria. Among the studies selected, 11 observed specific memory processing in PTSD patients, such as a greater memorization of negative information, or a trend to false recognition of negative information. In addition, attentional and inhibition processing seem to play an important role in emotional memory in PTSD sufferers. Furthermore, other studies that did not find behavioral differences between PTSD and control groups nevertheless showed differences in both specific cerebral activities and neurohormone levels during emotional memory tasks.Conclusion: This review has several limitations, including a limited number of controlled studies, small sample sizes, different tasks and methods. Nevertheless, the results of this systematic review provide interesting information on emotional memory for clinicians and researchers, as they seem to highlight facilitated memory processing for negative information in PTSD patients. This topic needs further controlled studies with sensitive behavioral tasks. Also, future studies may evaluate emotional memory after symptom amelioration.

Highlights

METHODEmotional memory refers to the attribution of emotional significance to a stimulus or event, promoting memory retention
Understanding how emotion interacts with memory, whether the emotional stimuli is related to a trauma or not, could be very beneficial to understand this disorder and suggest improvement in treatment for Post-Traumatic Stress Disorder (PTSD) patients
After full text reviews of the 72 remaining reports, 58 were excluded: 13 studies had a different population, 39 reports did not assess emotional memory with a cognitive task, 3 studies were not written in English, and 3 did not present study results or were poster presentations

Summary

Introduction

METHODEmotional memory refers to the attribution of emotional significance to a stimulus or event, promoting memory retention. With all its emotional intensity, as though it were occurring in the present: memories are intrusive, extremely distressing, and occur on a regular basis. These memories are often reported by PTSD patients, and are triggered by the presence of elements that recall the traumatic event and impact their daily life. Understanding how emotion interacts with memory, whether the emotional stimuli is related to a trauma or not, could be very beneficial to understand this disorder and suggest improvement in treatment for PTSD patients. Having a clearer view of the processes of interaction between memory and emotional stimuli in PTSD may improve our knowledge of this disorder, and could create new therapeutic management tools. We performed a systematic review of the evidence of specific emotional memory in PTSD patients

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Conclusion