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Chronic inflammation is a key factor in symptomology and comorbidities of post-traumatic stress disorder (PTSD). Levels of a proinflammatory marker, C-reactive protein (CRP) are increased in individuals with PTSD but it is not clear if this is due to trauma exposure or PTSD. Our study aimed to assess the relationship between serum CRP levels, CRP SNPs, methylation, mRNA expression and PTSD in a homogenous trauma exposed Australian Vietnam veteran cohort. We hypothesized that decreased DNA methylation would be associated with increased gene expression and increased peripheral CRP levels in PTSD patients and that this would be independent of trauma. Participants were 299 Vietnam veterans who had all been exposed to trauma and approximately half were diagnosed with PTSD. We observed higher levels of serum CRP in the PTSD group compared to the non-PTSD group but after controlling for BMI and triglycerides the association did not remain significant. No association was found between CRP SNPs and PTSD or CRP levels. Absent in Melanoma 2 (AIM2) which is a mediator of inflammatory response and a determinant of CRP levels was analysed for DNA methylation and mRNA expression. We observed a trend level association between PTSD and AIM2 methylation after controlling for age, smoking, triglycerides, BMI and cell types. There was no significant interaction between PTSD and CRP levels on AIM2 methylation after controlling for covariates. We observed that as AIM2 methylation levels decreased, AIM2 mRNA expression increased. Elevated CRP levels were associated with AIM2 mRNA in the trauma exposed cohort but there was no significant interaction effect with PTSD. Our results could not confirm that CRP is a marker of PTSD independent of trauma in this group of older veterans. CRP may be a broad marker of disease risk, or a marker of PTSD in younger cohorts than those in this study.

Introduction: The Diagnostic and Statistical Manual of Mental Disorders (5th ed.; DSM–5) brought a change to the symptom clusters of posttraumatic stress disorder (PTSD). In line with the DSM–5 changes, an updated version of the Clinician-Administered PTSD Scale (CAPS–5) was released. The CAPS–5 is considered to be the gold-standard measure of PTSD; however, examinations of the psychometric properties and optimal factor structure of this scale are underrepresented in PTSD studies. Methods: This study used confirmatory factor analysis (CFA) to assess the factor structure of the CAPS–5 using a sample of 267 male Australian Vietnam Veterans. Models drawn from the PTSD CFA literature were used to test the underlying dimensions of PTSD: the four-factor DSM–5 model, six-factor externalizing behaviour and anhedonia models, and seven-factor hybrid model. Results: The results found that the DSM–5 model showed slightly less than adequate fit (comparative fit index [CFI] = 0.90, Tucker–Lewis index [TLI] = 0.88, root mean square error of approximation [RMSEA] = 0.064), however, other models showed acceptable fit. The anhedonia model provided a significantly better fit than the other models (CFI = 0.92, TLI = 0.90, RMSEA = 0.059). Discussion: Overall, the results supported the anhedonia model. This result may indicate that the underlying dimensions of PTSD in Australian Vietnam Veterans may best be represented by six distinct factors.

Study Objectives: Disturbed sleep is a hallmark feature of posttraumatic stress disorder (PTSD). However, few studies have examined sleep objectively in individuals with PTSD compared to trauma-exposed controls. This study used wrist actigraphy to measure and compare sleep patterns in trauma-exposed Australian Vietnam veterans (VV) with and without PTSD. Methods: Trauma-exposed Australian VV with and without PTSD were recruited from the PTSD Initiative. VV wore wrist accelerometers over 14 days and completed daily sleep diaries. Sleep parameters were compared between groups including sleep latency (SL), time in bed (TIB), total sleep time (TST), wake after sleep onset (WASO), and movement index (MI). Night-to-night and overall within-individual variability were assessed by root mean squared successive differences and comparison of individual standard deviations. Correlations between sleep diary (self-reported) and wrist actigraphy (objective) variables were also assessed. Results: A total of 40 male VV (20 with PTSD) participated in the study. We found no difference in sleep patterns determined by wrist actigraphy between groups with the exception of reduced SL in VV with PTSD (3.9 ± 0.9 versus 4.9 ± 1.4 minutes, P < .05). Overall within-individual variability was significantly greater in VV with PTSD for TIB, TST, WASO, and MI. Self-reported and objective TST and WASO were more strongly correlated in VV without PTSD than those with PTSD. Conclusions: Although there were no significant differences in sleep parameters, VV with PTSD had increased within-individual overall sleep variability and reduced correlation between self-reported and objective sleep parameters compared to trauma-exposed controls. Further evaluation of extended sleep patterns by actigraphy in VV with PTSD is warranted.

In this study we investigated genome-wide sperm DNA methylation patterns in trauma-exposed Vietnam veterans. At the genome-wide level, we identified 3 CpG sites associated with PTSD in sperm including two intergenic and one CpG within the CCDC88C gene. Of those associated with PTSD in sperm at a nominal level, 1868 CpGs were also associated with PTSD in peripheral blood (5.6% overlap) including the RORA, CRHR1 and DOCK2 genes that have been previously implicated in PTSD. A total of 10 CpG sites were significantly associated with a reported history of a diagnosed mental health condition in children and reached genome-wide significance. CpGs associated with a history of a reported mental health condition in children were also enriched (90% of tested genes) for genes previously reported to be resistant to demethylation, making them strong candidates for transgenerational inheritance. In conclusion, our findings identify a unique sperm-specific DNA methylation pattern that is associated with PTSD.

Brain-derived neurotrophic factor (BDNF) gene is associated with increased risk of posttraumatic stress disorder (PTSD) and plays a role in neuroplasticity, cognition and memory. BDNF has strong potential as a therapeutic target as studies have shown that antidepressants, electroconvulsive treatment and exercise modulate BDNF expression and methylation. In this study we examined the role of BDNF methylation and expression in PTSD and the implications of exercise in mediating these effects. BDNF DNA methylation and gene expression analysis was performed in a sample of 96 male Vietnam veterans. Cases were combat-exposed veterans with current PTSD (n = 48) and controls were combat exposed veterans with no past or current PTSD diagnosis (n = 48). No association between BDNF mRNA and PTSD was identified. PTSD was associated with decreased methylation at three BDNF CpG sites (cg01546433 P = 0.004835; cg24650785 P = 0.000259 and cg002298481 P = 0.000672). Differential BDNF methylation was associated with exercise, with active exercise associated with lower methylation levels at three CpG sites (cg04481212 P = 0.005; cg01546433 P = 0.025 and cg00298481 P = 0.035). Given that exercise mediates BDNF action on cognitive plasticity, exercise may be a non-invasive, drug free option in the treatment of PTSD.

Accelerated epigenetic aging, the difference between the DNA methylation-predicted age (DNAm age) and the chronological age, is associated with a myriad of diseases. This study investigates the relationship between epigenetic aging and risk and protective factors of PTSD. Genome-wide DNA methylation analysis was performed in 211 individuals including combat-exposed Australian veterans (discovery cohort, n = 96 males) and trauma-exposed civilian males from the Grady Trauma Project (replication cohort, n = 115 males). Primary measures included the Clinician Administered PTSD Scale for DSM-5 and the Connor-Davidson Resilience Scale (CD-RISC). DNAm age prediction was performed using the validated epigenetic clock calculator. Veterans with PTSD had increased PTSD symptom severity (P-value = 3.75 × 10−34) and lower CD-RISC scores (P-value = 7.5 × 10−8) than veterans without PTSD. DNAm age was significantly correlated with the chronological age (P-value = 3.3 × 10−6), but DNAm age acceleration was not different between the PTSD and non-PTSD groups (P-value = 0.24). Evaluating potential protective factors, we found that DNAm age acceleration was significantly associated with CD-RISC resilience scores in veterans with PTSD, these results remained significant after multiple testing correction (P-value = 0.023; r = 0.32). This finding was also replicated in an independent trauma-exposed civilian cohort (P-value = 0.02; r = 0.23). Post-hoc factor analyses revealed that this association was likely driven by “self-efficacy” items within the CD-RISC (P-value = 0.015; r = 0.35). These results suggest that among individuals already suffering from PTSD, some aspects of increased resilience might come at a biological cost.

Study Objectives: Posttraumatic stress disorder (PTSD) is a condition that may develop after a traumatic event, particularly combat-related trauma. Although sleep disturbance is a hallmark of PTSD, the prevalence of sleep disturbances in Australian veterans with PTSD remains uncertain. This study aimed to subjectively compare the prevalence of sleep disturbances in Australian Vietnam veterans with and without PTSD. Methods: A cross-sectional cohort study compared trauma-exposed Australian Vietnam veterans with and without PTSD. PTSD diagnosis was confrmed using the Clinician Administered PTSD Scale for DSM-5. Sleep information was evaluated using supervised structured questionnaires, including Epworth Sleepiness Scale (ESS) and Berlin and Mayo Questionnaires. Results: Two hundred fourteen male Vietnam veterans (108 with PTSD) were included. Participants with PTSD had higher body mass index (30.3 versus 29 kg/m2; P < .05), higher ESS score (9.2 versus 7.6; P < .05), and increased alcohol or medication use to assist with sleep (19% versus 6%; P < .01; and 44% versus 14%; P < .01). Those with PTSD were less likely to sleep well (32% versus 72%; P < .01) and reported higher rates of restless legs (45% versus 25%; P < .01), nightmares (91% versus 29%; P < .01), nocturnal screaming (73% versus 18%; P < .01), sleep terrors (61% versus 13%; P < .01) and dream enactment (78% versus 11.8%; P < .01). The PTSD group had higher rates of diagnosed OSA (42% versus 21%; P < .01) and an increased risk of OSA on the Berlin Questionnaire (69% versus 43%; P < .01). Conclusions: Compared to trauma-exposed controls, Australian Vietnam veterans with PTSD demonstrated an increased prevalence of a wide range of sleep disturbances, including OSA. In veterans with PTSD, detailed sleep assessment, including consideration of polysomnography, is paramount.

Study Objectives Recent results from the PTSD Initiative, a cross-sectional cohort study in Australian Vietnam veterans (VV) with and without posttraumatic stress disorder (PTSD), demonstrated an increased prevalence of self-reported sleep disturbances in those with PTSD. This study aimed to objectively assess the prevalence of sleep disorders in the same cohort using detailed polysomnography (PSG). Methods Participants from the PTSD Initiative were recruited to undergo PSG. PTSD status was determined with the Clinician Administered PTSD Scale for DSM-5 (CAPS-5). Subjective sleep information was attained via structured questionnaires. Data from single night PSG were compared between trauma-exposed VV with and without PTSD. Results A total of 74 trauma-exposed male VV (40 with PTSD) underwent PSG (prospective n = 59, retrospective n = 15). All PSG parameters were similar between groups. No difference was seen in PSG-diagnosed obstructive sleep apnea (OSA) or periodic limb movements of sleep (PLMS). VV with PTSD showed a trend toward increased duration of sleep with oxygen saturations < 90% (10% versus 1.8%; P = .07). VV with PTSD reported increased sleep onset latency (42.4 versus 13.3 minutes; P < .01); were less likely to report sleeping well (32.5% versus 67.5%; P < .01); had higher OSA risk using Berlin Questionnaire (BQ) (70% versus 38.2%; P < .01); and had higher rates of partner-reported limb movements (56.4% versus 17.6%; P < .01). No association between PSG-diagnosed OSA and PTSD severity was evident. Conclusions In Australian VV with and without PTSD, no difference was seen across all PSG parameters including the diagnosis and severity of OSA and PLMS. However, VV with PTSD demonstrated an increased perception of sleep disturbances.

Background Posttraumatic stress disorder (PTSD) is a serious condition that emerges following trauma exposure and involves long-lasting psychological suffering and health-issues. Uncovering critical genes and molecular networks is essential to understanding the biology of the disorder. We performed a genome-wide scan to identify transcriptome signatures of PTSD. Methods Genome-wide peripheral blood transcriptomic data from 380 service personnel were investigated. This included a discovery sample of 96 Australian Vietnam War veterans and two independent pre and post-deployment replication samples of U.S. Marines (N = 188 and N = 96). Results A total of 60 transcripts were differentially expressed between veterans with and without PTSD, surviving Bonferroni multiple testing correction. Genes within the cytokine-cytokine receptor interaction, Jak-STAT signaling and Toll-like receptor signaling pathways were enriched. For 49% of the genes, gene expression changes were also accompanied by DNA methylation changes. Using replication data from two U.S. Marine cohorts, we observed that of the differentially expressed genes, 71% genes also showed significant gene expression changes between pre and post-deployment. Weighted gene co-expression networks revealed two modules of genes associated with PTSD. The first module (67 genes, p-value = 6e-4) was enriched for genes within the 11p13 locus including BDNF. The second module (266 genes, p-value = 0.01) was enriched for genes in 17q11 including SLC6A4, STAT5A and STAT5B. Conclusions We identified novel transcriptomic loci and biological pathways for PTSD in service personnel. Network analysis revealed enrichment of loci harboring key candidate genes in PTSD. These findings highlight the role of transcriptional biomarkers in the molecular etiology of PTSD.

Free to read on journal website (may need to create free account first) Objective To determine whether the prevalence of physical comorbidities in Australian Vietnam War veterans with post-traumatic stress disorder (PTSD) is higher than in trauma-exposed veterans without PTSD. Design, setting and participants: Cross-sectional analysis of the health status (based on self-reported and objective clinical assessments) of 298 Australian Vietnam War veterans enrolled by the Gallipoli Medical Research Institute (Brisbane) during February 2014 e July 2015, of whom 108 were confirmed as having had PTSD and 106 served as trauma-exposed control participants. Main outcomes and measures Diagnostic psychiatric interview and psychological assessments determined PTSD status, trauma exposure, and comorbid psychological symptoms. Demographic data, and medical and sleep history were collected; comprehensive clinical examination, electrocardiography, spirometry, liver transient elastography, and selected pathology assessments and diagnostic imaging were performed. Outcomes associated with PTSD were identified; regression analysis excluded the effects of potentially confounding demographic and risk factors and comorbid symptoms of depression and anxiety. Results The mean total number of comorbidities was higher among those with PTSD (17.7; SD, 6.1) than in trauma-exposed controls (14.1; SD, 5.2; P < 0.001). For 24 of 171 assessed clinical outcomes, morbidity was greater in the PTSD group, including for conditions of the gastrointestinal, hepatic, cardiovascular, and respiratory systems, sleep disorders, and laboratory pathology measures. In regression analyses including demographic factors, PTSD remained positively associated with 17 adverse outcomes; after adjusting for the severity of depressive symptoms, it remained significantly associated with ten. Conclusion PTSD in Australian Vietnam veterans is associated with comorbidities in several organ systems, i

Objective Epigenetic modifications such as DNA methylation may play a key role in the aetiology and serve as biomarkers for post-traumatic stress disorder (PTSD). We performed a genomewide analysis to identify genes whose DNA methylation levels are associated with PTSD. Method A total of 211 individuals comprising Australian male Vietnam War veterans (n = 96) and males from a general population belonging to the Grady Trauma Project (n = 115) were included. Genomewide DNA methylation was performed from peripheral blood using the Illumina arrays. Data analysis was performed using generalized linear regression models. Results Differential DNA methylation of 17 previously reported PTSD candidate genes was associated with PTSD symptom severity. Genomewide analyses revealed CpG sites spanning BRSK1, LCN8, NFG and DOCK2 genes were associated with PTSD symptom severity. We replicated the findings of DOCK2 in an independent cohort. Pathway analysis revealed that among the associated genes, genes within actin cytoskeleton and focal adhesion molecular pathways were enriched. Conclusion These data highlight the role of DNA methylation as biomarkers of PTSD. The results support the role of previous candidates and uncover novel genes associated with PTSD, such as DOCK2. This study contributes to our understanding of the biological underpinnings of PTSD.

The nitric oxide pathway in the hippocampus is involved in the biological stress response with detrimental consequences to cells and HPA axis feedback. Hippocampal atrophy and HPA axis feedback dysfunction are associated with posttraumatic stress disorder (PTSD). This study systematically investigates two genes of the nitric oxide pathway NOS1AP and NOS1 for a potential involvement in PTSD, comorbidities and resilience. A cohort of age and gender matched Vietnam veterans including trauma-exposed cases and controls was recruited and comprehensively assessed (n = 299). A total of 49 NOS1AP and 16 NOS1 polymorphisms were analysed and genotypes correlated with gold standard clinical measures to assess PTSD severity and related phenotypes (depression, anxiety, stress, resilience) based on diagnostic status. Multiple NOS1AP polymorphisms were associated across all measures, and NOS1 polymorphisms were associated with PTSD severity, stress and resilience. The GG genotype of NOS1 polymorphism rs10744891 was associated with PTSD severity (surviving multiple correction) while the combined TT-TG genotypes were associated with resilience (p = 0.005; p = 0.033, respectively). This study indicates that NOS1AP and NOS1 from the nitric oxide pathway are likely to play a key role in PTSD, its comorbidities and resilience. Given the essential role of NOS1AP and NOS1 in stress response they may be reliable targets for screening and intervention strategies.

Posttraumatic stress disorder (PTSD) is a debilitating condition that develops in some people after exposure to a traumatic event. Brain-derived neurotrophic factor (BDNF) is highly expressed in the mammalian brain and is thought to be involved in learning and memory processes. A nonsynonymous polymorphism in the BDNF gene, rs6265 (Val66Met), has been hypothesised to be associated with PTSD. Association studies examining the Val66Met polymorphism and PTSD have been inconclusive, likely due to the variability in type of trauma exposure analysed. Vietnam veterans (n = 257) screened for PTSD and controlled for trauma exposure were genotyped for BDNF Val66Met. The association was not significant so we incorporated our data into a meta-analysis to obtain greater statistical power. A comprehensive search of more than 1237 articles revealed eight additional studies suitable for meta-analysis (n = 3625). A random-effects meta-analysis observed a potential protective factor of the Val/Val genotype. After removing two studies with violation of Hardy-Weinberg equilibrium, findings for the Val/Val genotype reached significance. Subgroup analyses confirmed a trend for this finding. Limitations of some studies that inform this meta-analysis include poorly screened controls and a lack of examination of population stratification. Effectively designed studies should inform this line of research in the future.