Association between posttraumatic stress disorder severity and amygdala habituation to fearful stimuli

• Type of Material: Article
• Authors: Ye Ji Kim, Emory University; Sanne van Rooij, Emory University; Timothy D. Ely, Emory University; Negar Fani, Emory University; Kerry Ressler, Emory University; Tanja Jovanovic, Emory University; Jennifer Stevens, Emory University
• Language: English
• Date: 2019-07-01
• Publisher: Wiley
• Publication Version: Author Accepted Manuscript (After Peer Review)
• Copyright Statement: © 2019 John Wiley & Sons, Inc. All rights reserved.
• Final Published Version (URL): http://dx.doi.org/10.1002/da.22928
• Title of Journal or Parent Work: Depression and Anxiety
• Volume: 36
• Issue: 7
• Start Page: 647
• End Page: 658
• Grant/Funding Information: National Center for Research Resources, Grant/Award Number: M01RR00039; National Center for Advancing Translational Sciences, Grant/Award Number: UL1TR000454;; National Institute of Mental Health, Grant/Award Numbers: MH098212, MH071537, MH101380, MH101976, MH096764;; Eunice Kennedy Shriver National Institute of Child Health and Human Development, Grant/Award Number: HD085850; National Heart, Lung, and Blood Institute (NHLBI), Grant/Award Number: T32HL130025
• Keywords: Psychology; Social Sciences; Blood flow; PTSD; Reliability; trauma; fear; fMRI; Childhood sexual abuse; habituation; Psychology, Clinical; amygdala; Life Sciences & Biomedicine; Functional MRI; Prolonged exposure therapy; Prefrontal cortex; Psychiatry; Trauma; Gill withdrawal reflex; Science & Technology
• Research Categories: Psychology, Clinical; Psychology, Behavioral; Health Sciences, Epidemiology

Abstract

Background: Amygdala hyperreactivity to threat has been proposed to be a causal contributor to posttraumatic stress disorder (PTSD). However, emerging literature in healthy samples shows higher test-retest reliability for amygdala habituation (the change over time in response to repeated stimuli) than for its reactivity to threat. Amygdala habituation has received relatively little attention in relationship to PTSD, despite the key role of this region in the etiology of the disorder. Thus, we investigated habituation to repeated fearful face stimuli and PTSD, in a large sample of trauma exposed African American women. Methods: African American women (N = 100) were recruited from a nonprofit hospital serving a largely low-income population with a high risk of trauma exposure. Participants underwent functional magnetic resonance imaging, passively viewing fearful and neutral face stimuli, and reported their history of trauma exposure and current PTSD symptoms. We examined associations between PTSD symptom severity and amygdala reactivity (fearful > neutral) and habituation (early > late) to fearful faces. Secondary analyses tested whether amygdala habituation to fearful faces mediated the association between childhood trauma and PTSD. Results: PTSD symptom severity and PTSD status (based on self-report measure) were both positively associated with amygdala habituation to repeated fearful face stimuli. Whole-brain analysis showed that this association extended to the bilateral hippocampus and left fusiform gyrus. The association held when controlling for trauma history and depressive symptoms. Amygdala habituation to fearful faces partially mediated the association between childhood trauma severity and PTSD symptom severity. Conclusion: Individuals with greater PTSD symptom severity showed greater amygdala habituation to social threat cues (fearful faces), and greater habituation may partly explain the association between childhood trauma exposure and current PTSD symptoms. Further examination of the dynamics of the amygdala response to threat cues may lead to new insights in the understanding and treatment of stress-related disorders.