Alterations in large-scale functional networks in adult posttraumatic stress disorder: A systematic review and meta-analysis of resting-state functional connectivity studies

The relationship between recent PTSD secondary to sexual assault, hippocampal volume and resting state functional connectivity in adolescent girls

“…We found no differences in total hippocampal volume when comparing participants with PTSD with age- and gender-matched non-trauma exposed HCs. We found that girls with PTSD had decreased within DMN connectivity, consistent with previous studies examining RSFC in PTSD in adults ( Koch et al, 2016 ; Miller et al, 2017 ; Sheynin et al, 2020 ), including a meta-analysis ( Bao et al, 2021 ), and studies examining RSFC in adolescents with and without PTSD ( Sheynin et al, 2020 ; Viard et al, 2019 ). More specifically, we found PTSD-related decreased connectivity between hippocampus and angular gyrus, a region encompassed by the lateral parietal node of the DMN, compared to HCs ( Table 2 ; Fig.…”

“…Stress-induced dendritic hypotrophy could be associated with reductions in hippocampal connectivity, and stress-driven reductions in dendritic complexity in rodents have been suggested as a possible mechanism for the reductions in hippocampal volume observed in participants with PTSD ( Fenster et al, 2018 ). Consistent with rodent studies finding hippocampal dendritic hypotrophy following stress exposure, human studies of hippocampal function, via functional magnetic resonance imaging (fMRI), have found reduced hippocampal resting state functional connectivity (RSFC) in PTSD ( Bao et al, 2021 ; Koch et al, 2016 ; Miller et al, 2017 ; Sheynin et al, 2020 ; Viard et al, 2019 ).…”

“…Self-referential cognitive processing is altered in women with PTSD such that individuals with PTSD endorse more negative and fewer positive self-descriptive adjectives ( Frewen et al, 2011 ); therefore, it is not surprising that altered DMN connectivity has also been found in PTSD ( Viard et al, 2019 ). More specifically, both adults and adolescents with PTSD have been found to have reduced RSFC between nodes of the DMN in which the hippocampus can be included ( Bao et al, 2021 ; Koch et al, 2016 ; Miller et al, 2017 ; Sheynin et al, 2020 ; Viard et al, 2019 ). Furthermore, reduced connectivity between hippocampus and DMN nodes has been found to relate to PTSD symptoms: in adolescents with PTSD, increased symptom severity has been associated with reduced RSFC between the hippocampus and the posterior cingulate cortex, another node of the DMN ( Sheynin et al, 2020 ; Viard et al, 2019 ).…”

COVID‐19 vicarious traumatization links functional connectome to general distress

“…Neurofunctionally, a significant component of the variance in general distress could be explained by the functional connectome. Although few studies have investigated the relationship between functional connectome and general distress, there is abundant evidence for a role of functional connectivity in depression, anxiety and stress ( Harnett et al, 2021 ; van Oort et al, 2020 ), which are increasingly understood as network-based disorders ( Bao et al, 2021 ; Mulders et al, 2015 ; Xu et al, 2019 ). For example, functional connectivity within DMN, and between DMN and SN/FPN, are altered in depression ( Mulders et al, 2015 ); anxiety is characterized by hypo-connectivity of multiple brain networks, notably the FPN, DMN, SN and motor network ( Xu et al, 2019 ); stress can be linked to the balance between FPN and SN ( Hermans et al, 2014 ; Hermans et al, 2011 ).…”

Towards Assessing Subcortical “Deep Brain” Biomarkers of PTSD with Functional Near-Infrared Spectroscopy

“…Additionally, researchers could study deep brain activity and associated PTSD behavior (e.g., heightened fear, anxiety, and aggression responses) in naturalistic settings, which would advance understanding of brain mechanisms underlying PTSD in youths and adults. However, because PTSD is associated with aberrant brain function in both deep brain and NIRS-inaccessible cortical regions (Cui et al 2011; Suarez-Jimenez et al 2020; Bao et al 2021), it is unclear whether the deep brain inference method is suitable for individuals with PTSD. Additionally, changes in functional connectivity related to brain development (Blakemore et al 2010; Goddings et al 2014; Vijayakumar et al 2018) could pose further challenges for using this deep brain inference method in pediatric samples.…”