Combat exposure, posttraumatic stress disorder, and head injuries differentially relate to alterations in cortical thickness in military Veterans.
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ABSTRACT:
SUBMITTER: Clausen AN
PROVIDER: S-EPMC6969074 | biostudies-literature | 2020 Feb
REPOSITORIES: biostudies-literature
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Combat exposure, posttraumatic stress disorder, and head injuries differentially relate to alterations in cortical thickness in military Veterans.
Clausen Ashley N AN Clarke Emily E Phillips Rachel D RD Haswell Courtney C Morey Rajendra A RA
Neuropsychopharmacology : official publication of the American College of Neuropsychopharmacology 20191010 3
Combat-exposed Veterans are at increased risk for developing psychological distress, mood disorders, and trauma and stressor-related disorders. Trauma and mood disorders have been linked to alterations in brain volume, function, and connectivity. However, far less is known about the effects of combat exposure on brain health. The present study examined the relationship between severity of combat exposure and cortical thickness. Post-9/11 Veterans (N = 337; 80% male) were assessed with structural ...[more]
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Project description:Objective: Posttraumatic stress disorder (PTSD) affects a high proportion of returning combat veterans, but the biological mechanisms of PTSD remain unclear. Circulating micro RNAs (miRNAs) have been associated with depression, and anxiety disorders, but there is little understanding of how miRNAs may relate to PTSD. In this study we compare profiles of circulating miRNA in combat veterans with and without PTSD in order to better understand biological mechanisms of PTSD. Methods: Blood from 24 male military service members was collected following deployment to Operation Iraqi Freedom (OIF) or Operation Enduring Freedom (OEF), and subjects were assessed for PTSD symptoms using the PTSD checklist-military version. miRNA was isolated from whole blood and sequenced on the Ion Torrent PGM™ using the Ion 316 Chip v2. Differences in miRNA expression was compared between subjects with PTSD (N=15) and combat matched controls without PTSD (N=9). Significantly different miRNA, according to a FDR≤0.05, were assessed for predictive putative targets, and pathway analysis of related targets was completed. Results: PTSD was associated with 4 upregulated and 4 downregulated miRNA, including a 2.94 fold increase in miR-19a-3p and a 1.56 fold decrease in miR-15b. Pathway analysis show that PTSD is related to the axon guidance and Wnt signaling pathways, which work together along with the adherens junction and MAPK signaling pathways to support neuronal development through regulation of growth cones. The PTSD associated miRNAs related to transcription factors, including Transcription factor 7 (T-cell specific, HMG-box), Transcription factor 7 like 1, and Transcription factor 7 like 2. Conclusions: PTSD is associated with miRNAs that regulate biological functions that include neuronal activities, suggesting that they play a role in PTSD symptomatology.
2017-03-07 | GSE87768 | GEO
Project description:Posttraumatic stress disorder (PTSD) affects many returning combat veterans, but underlying biological mechanisms remain unclear. In order to compare circulating micro RNA (miRNA) of combat veterans with and without PTSD, peripheral blood from 24 subjects was collected following deployment, and isolated miRNA was sequenced. PTSD was associated with 8 differentially expressed miRNA. Pathway analysis shows that PTSD is related to the axon guidance and Wnt signaling pathways, which work together to support neuronal development through regulation of growth cones. PTSD is associated with miRNAs that regulate biological functions including neuronal activities, suggesting that they play a role in PTSD symptomatology.
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Project description:We investigated the extent of cortical thinning in U.S. Veterans exposed to combat who varied in the severity of their posttraumatic stress disorder (PTSD) symptoms. In addition, we explored the neural correlates of PTSD symptom dimensions and the interactive effects of combat exposure and PTSD upon cortical thickness. Sixty-nine combat exposed Veterans completed high-resolution magnetic resonance imaging (MRI) scans to estimate cortical thickness. The Clinician Administered PTSD Scale (CAPS) and Combat Exposure Scale (CES) assessments were completed to measure current PTSD and historical combat severity, respectively. PTSD symptom dimensions (numbing, avoidance, reexperiencing, anxious arousal, and dysphoric arousal) were studied. Vertex-wise whole cerebrum analyses were conducted. We found widespread negative correlations between CAPS severity and cortical thickness, particularly within the prefrontal cortex. This prefrontal correlation remained significant after controlling for depression severity, medication status, and other potential confounds. PTSD dimensions, except anxious arousal, negatively correlated with cortical thickness in various unique brain regions. CES negatively correlated with cortical thickness in the left lateral prefrontal, regardless of PTSD diagnosis. A significant interaction between CES and PTSD diagnosis was found, such that CES negatively correlated with cortical thickness in the non-PTSD, but not in the PTSD, participants. The results underscore the severity of cortical thinning in U.S. Veterans suffering from high level of PTSD symptoms, as well as in Veterans with no PTSD diagnosis but severe combat exposure. The latter finding raises considerable concerns about a concealed injury potentially related to combat exposure in the post-9/11 era.
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Project description:Two decades of human neuroimaging research have associated volume reductions in the hippocampus with posttraumatic stress disorder. However, little is known about the distribution of volume loss across hippocampal subfields. Recent advances in neuroimaging methods have made it possible to accurately delineate 10 gray matter hippocampal subfields. Here, we apply a volumetric analysis of hippocampal subfields to data from a group of combat-exposed Veterans. Veterans (total, n = 68, posttraumatic stress disorder, n = 36; combat control, n = 32) completed high-resolution structural magnetic resonance imaging. Based on previously validated methods, hippocampal subfield volume measurements were conducted using FreeSurfer 6.0. The Clinician-Administered PTSD Scale assessed posttraumatic stress disorder symptom severity; Beck Depression Inventory assessed depressive symptom severity. Controlling for age and intracranial volume, partial correlation analysis examined the relationship between hippocampal subfields and symptom severity. Correction for multiple comparisons was performed using false discovery rate. Gender, intelligence, combat severity, comorbid anxiety, alcohol/substance use disorder, and medication status were investigated as potential confounds. In the whole sample, total hippocampal volume negatively correlated with Clinician-Administered PTSD Scale and Beck Depression Inventory scores. Of the 10 hippocampal subfields, Clinician-Administered PTSD Scale symptom severity negatively correlated with the hippocampus-amygdala transition area (HATA). Beck Depression Inventory scores negatively correlated with dentate gyrus, cornu ammonis 4 (CA4), HATA, CA2/3, molecular layer, and CA1. Follow-up analysis limited to the posttraumatic stress disorder group showed a negative correlation between Clinician-Administered PTSD Scale symptom severity and each of HATA, CA2/3, molecular layer, and CA4. This study provides the first evidence relating posttraumatic stress disorder and depression symptoms to abnormalities in the HATA, an anterior hippocampal region highly connected to prefrontal-amygdala circuitry. Notably, dentate gyrus abnormalities were associated with depression severity but not posttraumatic stress disorder symptoms. Future confirmatory studies should determine the extent to which dentate gyrus volume can differentiate between posttraumatic stress disorder- and depression-related pathophysiology.
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Project description:Psychiatric symptoms typically cut across traditional diagnostic categories. In order to devise individually tailored treatments, there is a need to identify the basic mechanisms that underlie these symptoms. Behavioral economics provides a framework for studying these mechanisms at the behavioral level. Here, we utilized this framework to examine a widely ignored aspect of trauma-related symptomatology-individual uncertainty attitudes-in combat veterans with and without posttraumatic stress disorder (PTSD).Fifty-seven combat veterans, including 30 with PTSD and 27 without PTSD, completed a risk and ambiguity decision-making task that characterizes individual uncertainty attitudes, distinguishing between attitudes toward uncertain outcomes with known ("risk") and unknown ("ambiguity") probabilities, and between attitudes toward uncertain gains and uncertain losses. Participants' choices were used to estimate risk and ambiguity attitudes in the gain and loss domains.Veterans with PTSD were more averse to ambiguity, but not risk, compared to veterans without PTSD, when making choices between possible losses, but not gains. The degree of aversion was associated with anxious arousal (e.g., hypervigilance) symptoms, as well as with the degree of combat exposure. Moreover, ambiguity attitudes fully mediated the association between combat exposure and anxious arousal symptoms.These results provide a foundation for prospective studies of the causal association between ambiguity attitudes and trauma-related symptoms, as well as etiologic studies of the neural underpinnings of these behavioral outcomes. More generally, these results demonstrate the potential of neuroeconomic and behavioral economic techniques for devising objective and incentive-compatible diagnostic tools, and investigating the etiology of psychiatric disorders.
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Project description:Study objectivesTo examine the efficacy of imagery rehearsal (IR) combined with cognitive behavioral therapy for insomnia (CBT-I) compared to CBT-I alone for treating recurrent nightmares in military veterans with posttraumatic stress disorder (PTSD).MethodsIn this randomized controlled study, 108 male and female United States veterans of the Iraq and Afghanistan conflicts with current, severe PTSD and recurrent, deployment-related nightmares were randomized to six sessions of IR + CBT-I (n = 55) or CBT-I (n = 53). Primary outcomes were measured with the Nightmare Frequency Questionnaire (NFQ) and Nightmare Distress Questionnaire (NDQ).ResultsImprovement with treatment was significant (29% with reduction in nightmare frequency and 22% with remission). Overall, IR + CBT-I was not superior to CBT-I (NFQ: -0.12; 95% confidence interval = -0.87 to 0.63; likelihood ratio chi square = 4.7(3), P = .2); NDQ: 1.5, 95% confidence interval = -1.4 to 4.4; likelihood ratio chi square = 7.3, P = .06).ConclusionsCombining IR with CBT-I conferred no advantage overall. Further research is essential to examine the possibly greater benefit of adding IR to CBT-I for some subgroups of veterans with PTSD.Clinical trial registrationRegistry: ClinicalTrials.gov; Title: Cognitive Behavioral Therapy (CBT) for Nightmares in Operation Enduring Freedom/Operation Iraqi Freedom (OEF/OIF) Veterans; Identifier: NCT00691626; URL: https://clinicaltrials.gov/ct2/show/NCT00691626.
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Project description:BackgroundThe amygdala is a subcortical structure involved in socioemotional and associative fear learning processes relevant for understanding the mechanisms of posttraumatic stress disorder (PTSD). Research in animals indicates that the amygdala is a heterogeneous structure in which the basolateral and centromedial divisions are susceptible to stress. While the amygdala complex is implicated in the pathophysiology of PTSD, little is known about the specific contributions of the individual nuclei that constitute the amygdala complex.MethodsMilitary veterans (n = 355), including military veterans with PTSD (n = 149) and trauma-exposed control subjects without PTSD (n = 206), underwent high-resolution T1-weighted anatomical scans. Automated FreeSurfer segmentation of the amygdala yielded 9 structures: basal, lateral, accessory basal, anterior amygdaloid, and central, medial, cortical, and paralaminar nuclei, along with the corticoamygdaloid transition zone. Subregional volumes were compared between groups using ordinary-least-squares regression with relevant demographic and clinical regressors followed by 3-dimensional shape analysis of whole amygdala.ResultsPTSD was associated with smaller left and right lateral and paralaminar nuclei, but with larger left and right central, medial, and cortical nuclei (p < .05, false discovery rate corrected). Shape analyses revealed lower radial distance in anterior bilateral amygdala and lower Jacobian determinant in posterior bilateral amygdala in PTSD compared with control subjects.ConclusionsAlterations in select amygdala subnuclear volumes and regional shape distortions are associated with PTSD in military veterans. Volume differences of the lateral nucleus and the centromedial complex associated with PTSD demonstrate a subregion-specific pattern that is consistent with their functional roles in fear learning and fear expression behaviors.
| S-EPMC8040290 | biostudies-literature