Diverging roles of the anterior insula in trauma-exposed individuals vulnerable or resilient to posttraumatic stress disorder

Hyeonseok Jeong,Myeongju Kim,Yong-An Chung,Jin Kyoung Oh,Gahae Hong,In Kyoon Lyoo,Sujung Yoon,Haejin Hong,Eunji Ha,Jungyoon Kim,Jiyoung Ma

doi:10.1038/s41598-019-51727-3

Abstract

Distinct brain alterations in response to traumatic events may render trauma-exposed individuals either resilient or vulnerable to posttraumatic stress disorder (PTSD). This study compared regional cerebral metabolic rate of glucose (rCMRglu) among trauma-exposed individuals with current PTSD (PTSD group, n = 61), those without current PTSD (Resilience/Recovery group, n = 26), and trauma-unexposed controls (Control group, n = 54). All participants underwent brain [18F]-fluorodeoxyglucose positron emission tomography (FDG-PET) scans. Voxel-wise group differences in rCMRglu among the three groups were evaluated. Associations between rCMRglu and both PTSD severity and resilience were examined. The rCMRglu in the right anterior insula and adjacent prefrontal and striatal areas was lower in the PTSD group, while higher in the Resilience/Recovery group, compared to the Control group. In addition, the lower glucose metabolism of these areas was associated with higher severity and less improvement in PTSD symptoms in the PTSD group, while the higher levels of rCMRglu were correlated with stronger resilience in the Resilience/Recovery group. This study suggests distinct roles of the anterior insula in response to trauma between the PTSD and Resilience/Recovery groups. Heightened rCMRglu in the anterior insular regions may reflect an underlying mechanism of resilience against traumatic stress, while reduced rCMRglu may indicate vulnerability to PTSD.

Highlights

Distinct brain alterations in response to traumatic events may render trauma-exposed individuals either resilient or vulnerable to posttraumatic stress disorder (PTSD)
In the Resilience/Recovery group, 16 (61.5%) participants had been previously diagnosed with PTSD, from which they recovered at the time of the assessment
The results from the abovementioned correlational analyses remained unchanged even with time since the index trauma, type of index trauma, and concurrent use of psychotropic medication included as an additional covariate, respectively (Supplementary Table 4). This is the largest fluorodeoxyglucose positron emission tomography (FDG-PET) study to date that investigated differences in regional cerebral metabolic rate of glucose (rCMRglu) among trauma-exposed individuals according to the presence of PTSD

Summary

Introduction

Distinct brain alterations in response to traumatic events may render trauma-exposed individuals either resilient or vulnerable to posttraumatic stress disorder (PTSD). Previous studies have detected significant differences in structural and functional alterations of the brain between trauma-exposed individuals with and without PTSD, as compared with trauma-unexposed controls[5,6,7]. These results may suggest that the neurobiological characteristics of trauma-exposed individuals show a distinct pattern depending on the development of full-blown PTSD, as opposed to the common belief that neurobiological changes occur along a continuum according to PTSD symptom severity. Regional cerebral metabolic rate of glucose (rCMRglu) in trauma-exposed groups, all of which were limited in the number of trauma-exposed subjects[8]

Methods

Results

Conclusion