Reduced hippocampal volume is frequently observed in posttraumatic stress disorder (PTSD), but the exact psychological processes associated with these alterations remain unclear. Given the role of the hippocampus in contextual representations of threat and memory, we investigated relationships between retrospectively reported combat exposure, perceived threat, and hippocampal volume in trauma-exposed veterans. T1-weighted anatomical images were obtained from a sample of 52 male veterans with a broad range of PTSD symptoms during MRI scanning. Hippocampal volume was estimated using automatic segmentation tools in FreeSurfer. An index of Perceived Threat Bias (PTB) was calculated, reflecting the degree of discordance between subjective perceptions of threat while deployed and self-reported combat exposure. Hippocampal volume was regressed on PTB and PTSD symptoms on the Clinician-Administered PTSD Scale (CAPS). Results indicated that perceived threat bias was unrelated to overall CAPS symptoms, but was positively associated with CAPS avoidance/numbing symptoms and symptoms of depression, anxiety, and worry. Elevated PTB was associated with smaller hippocampal volume for individuals with a wide range of PTSD symptoms. Hippocampal volume was also inversely related to avoidance/numbing CAPS symptoms. These results indicate that volume of the hippocampus, a region involved in contextual threat processing and memory, is related to recalled associations between traumatic events and accompanying subjective threat appraisals. Future research should clarify the precise temporal milieu of these effects and investigate whether individual differences in hippocampal structure and function contribute to exaggerated threat appraisal at the time of trauma, or in subsequently biased memories or appraisals of traumatic events.
- Downloaded 257 times
- Download rankings, all-time:
- Site-wide: 56,314 out of 84,692
- In neuroscience: 10,007 out of 15,080
- Year to date:
- Site-wide: 60,589 out of 84,692
- Since beginning of last month:
- Site-wide: 72,599 out of 84,692
Downloads over time
Distribution of downloads per paper, site-wide
- 18 Dec 2019: We're pleased to announce PanLingua, a new tool that enables you to search for machine-translated bioRxiv preprints using more than 100 different languages.
- 21 May 2019: PLOS Biology has published a community page about Rxivist.org and its design.
- 10 May 2019: The paper analyzing the Rxivist dataset has been published at eLife.
- 1 Mar 2019: We now have summary statistics about bioRxiv downloads and submissions.
- 8 Feb 2019: Data from Altmetric is now available on the Rxivist details page for every preprint. Look for the "donut" under the download metrics.
- 30 Jan 2019: preLights has featured the Rxivist preprint and written about our findings.
- 22 Jan 2019: Nature just published an article about Rxivist and our data.
- 13 Jan 2019: The Rxivist preprint is live!