Mood symptoms contribute to working memory decrement in active-duty soldiers being treated for posttraumatic stress disorder

The effect of eye movement desensitization on neurocognitive functioning compared to retrieval-only in PTSD patients: a randomized controlled trial

BACKGROUND

There is robust evidence that posttraumatic stress disorder (PTSD) is associated with neurocognitive deficits, such as executive dysfunction or memory dysfunction. Eye Movement Desensitization and Reprocessing (EMDR) is an evidence-based treatment for PTSD, in which eye movements (EMs) are performed during traumatic memory retrieval. We examined whether Eye Movement Desensitization (EMD) improves neurocognitive functioning in PTSD patients, in comparison with a retrieval-only control condition without EMs.

METHODS

Adult patients with PTSD (N = 91) were randomized into EMD (N = 47) or retrieval-only (N = 44). Data were collected at baseline (T0), one-week post-treatment (T1), one-month follow-up (T2), and at three-month follow-up (T3). Outcome measures were the California Verbal Learning Test (CVLT), the Trail Making Test (TMT), and the Digit Span Subtest of the Wechsler Adult Intelligence Scale fourth edition (WAIS-IV). We conducted linear mixed model to analyse the main outcomes.

RESULTS

There was a main effect of time, indicating improvements for both the EMD and retrieval-only groups in CVLT scores, TMT A, TMT B and Digit Span score of WAIS-IV (Bonferroni-adjusted p's < 0.001) from T0 to T3. There were no effects of group (p = .64) or group by time on CVLT total trial A (T3; p = .34), delay A (T3; p = .76), TMT A (T3; p = .61), TMT B (T3: p = .58), and Digit Span scores (T3; p = .78) of the WAIS-IV, indicating no significant differences between groups on any of the outcomes.

CONCLUSION

Comparing EMD and retrieval-only did not show evidence for additive effects of EMs on the treatment of PTSD in terms of improvements in neurocognitive functioning. Thus, treatments based on retrieval of traumatic memories may be used to improve neurocognitive functioning in patients with PTSD.

CLINICAL TRIAL REGISTRATION

The trial was registered 19/12/2017 at ClinicalTrials.gov, identifier [ISRCTN55239132].

Reciprocal associations of posttraumatic stress symptoms and cognitive decline in community-dwelling older adults: The mediating role of depression

BACKGROUND

People with posttraumatic stress disorder (PTSD) may have cognitive decline, a risk which can be particularly threatening at old age. However, it is yet unclear whether initial cognitive decline renders one more susceptible to subsequent PTSD following exposure to traumatic events, whether initial PTSD precedes cognitive decline or whether the effects are reciprocal.

OBJECTIVE

This study examined the bidirectional longitudinal associations between cognitive function and PTSD symptoms and whether this association is mediated by depressive symptoms.

METHOD

The study used data from two waves of the Israeli component of the Survey of Health, Ageing, and Retirement in Europe (SHARE), collected in 2013 and 2015. This study focused on adults aged 50 years and above (N = 567, mean age = 65.9 years). Each wave used three measures of cognition (recall, fluency, and numeracy) and PTSD symptoms following exposure to war-related events. Data were analyzed using mediation analysis with path analysis.

RESULTS

Initial PTSD symptoms predicted cognitive decline in recall and fluency two years later, while baseline cognitive function did not impact subsequent PTSD symptoms. Partial mediation showed that older adults with more PTSD symptoms had higher depressive symptoms, which in turn were linked to subsequent cognitive decline across all three measures.

CONCLUSIONS

This study reveals that PTSD symptoms are linked with subsequent cognitive decline, supporting approaches addressing this direction. It further indicates that part of this effect can be explained by increased depressive symptoms. Thus, treatment for depressive symptoms may help reduce cognitive decline due to PTSD.

The association between post-traumatic stress disorder (PTSD) and executive functioning

Introduction: Post-Traumatic Stress Disorder (PTSD) is a condition characterised by several disturbances in an individual's executive functioning. We were interested in the link between executive functions and the presence of anxiety and depression in a clinical population with post-traumatic stress disorder.Methods: Our sample comprised 180 participants divided into three groups: 60 with PTSD, 60 trauma-exposed without PTSD, and 60 controls. All participants were assessed on the following dimensions: PTSD, dissociation, executive functions, anxiety, and depression.Results: Consistent with the literature, the results of our study suggest that individuals with PTSD have difficulties in executive functioning. These disturbances are related to levels of anxiety and depression.Conclusion: The severity of PTSD is positively correlated with executive function disturbances, but the observed disturbances, especially in working memory updating, can be explained mainly by the high level of depression, rather than by PTSD alone.

Altered dynamic functional connectivity associates with post-traumatic stress disorder

Research has been looking into neural pathophysiology of post-traumatic stress disorder (PTSD) and dynamic functioning connectivity (dFC) applying resting state functional magnetic resonance imaging (rs-fMRI). Previous studies showed that PTSD related impairments are associated with alterations distributed across different brain regions and disorganized functional connectivity, especially in Default Mode Network and the cerebellar area. In this study, we specifically looked into dFC on a whole brain level, and we focused on critical regions such as DMN and cerebellum. To explore the characteristics of dFC among patients with PTSD, we collected rs-fMRI data from 27 PTSD patients and 30 healthy controls. The study also added a control group of 33 trauma-exposed individuals to further look into trauma impact. Utilizing group spatial independent component analysis (ICA), the dynamic properties on whole brain level were detected with sliding time window approach, and k-means clustering. Two reoccurring FC "States" were identified, with connections being more concentrated on a within-network level in one state and more strongly inter-connected in the other state. Abnormalities in dFC were found within DMN, between DMN and cerebellum, and between DMN and visual network for PTSD patients. The findings were in accordance with the study hypothesis that the dFC alterations might point to deficits in emotional modulation and dysfunctional self-referential thought. Abnormalities in dFC among PTSD patients might also be indicators of PTSD symptoms including depression and anxiety, hypervigilance, impaired cognitive functioning and self-referential information processing.

Contributory Etiologies to Cognitive Performance in Multimorbid Post-9/11 Veterans: The Deployment Trauma Phenotype

OBJECTIVE

This study examined cognitive functioning in post-9/11 Veterans with the deployment trauma phenotype (DTP), comprised of co-occurring diagnoses of depressive disorder (major depressive disorder and or persistent depressive disorder/dysthymia), posttraumatic stress disorder (PTSD), and mild traumatic brain injury (mTBI), using objective neuropsychological measures.

METHOD

Participants included a cross-sectional sample of 399 post-9/11 Veterans who completed clinical interviews and neuropsychological tests as part of a larger study at VA Boston Healthcare System. Confirmatory factor analysis identified four cognitive domains: attention, cognitive control/processing speed, episodic memory, and cognitive flexibility. Veterans with DTP and its constituent diagnoses in isolation, two-way diagnostic combinations, and no constituent diagnoses were compared.

RESULTS

Veterans with DTP had a twofold increased prevalence for below average performance in cognitive control/processing speed compared with those with no constituent diagnoses (prevalence ratios [PRs] = 2.04; 95% confidence interval [CI]: 1.03-4.05). The PTSD + depressive disorder group also had a twofold increased prevalence for below average performance in episodic memory (PR = 2.16; 95% CI: 1.05-4.43).

CONCLUSIONS

The deployment trauma phenotype is associated with clinically significant decrease in cognitive control/processing speed in post-9/11 Veterans. Comorbid PTSD and depressive disorder negatively impacted performances in episodic memory. Mild TBI alone showed no cognitive deficits. Clinical interventions should target psychiatric symptoms with a transdiagnostic approach to address this multimorbid population.

Association between spatial working memory and Re-experiencing symptoms in PTSD

BACKGROUND AND OBJECTIVES

Few studies have evaluated the link between working memory (WM) and post-traumatic stress disorder (PTSD). Further, it is unknown whether this relationship is accounted for by other relevant variables including negative affect, emotional dysregulation, or general non-WM-related cognitive control deficits, which are associated with PTSD. The purpose of this study was to determine the extent to which a computerized WM task could predict PTSD symptomology incrementally beyond the contribution of other relevant variables associated with PTSD.

METHODS

Thirty veterans were eligible to complete emotional symptom questionnaires, a heart-rate variability measure, and computerized tasks (i.e., emotional Stroop and automated complex span tasks). A three-stage hierarchical regression was conducted with the PCL-5 total score and symptom clusters (i.e., re-experiencing, avoidance, hyperarousal, and negative cognition/mood) as the dependent variable.

RESULTS

Results revealed that only the re-experiencing symptom cluster was significantly predicted by executive, verbal, and visuospatial WM tasks, which explained an additional 29.7% of the variance over and above other relevant variables. Most notably, the visuospatial task was the only WM task that significantly explained PCL-5 re-experiencing symptoms.

LIMITATIONS

This study was based on a small sample of veterans with PTSD and causality cannot be determined with this cross-sectional study.

CONCLUSIONS

Overall, the results suggest that deficits in visuospatial WM are significantly associated with PTSD re-experiencing symptoms after controlling for other relevant variables. Further research should evaluate whether an intervention to improve visuospatial WM capacity can be implemented to reduce re-experiencing symptoms.

Individuals with and without military-related PTSD differ in subjective sleepiness and alertness but not objective sleepiness

Posttraumatic stress disorder-related sleep disturbances may increase daytime sleepiness and compromise performance in individuals with posttraumatic stress disorder. We investigated nighttime sleep predictors of sleepiness in Veterans with and without posttraumatic stress disorder. Thirty-seven post-9/11 Veterans with posttraumatic stress disorder and 47 without posttraumatic stress disorder (Control) completed a 48-h lab stay. Nighttime quantitative EEG and sleep architecture parameters were collected with polysomnography. Data from daytime sleepiness batteries assessing subjective sleepiness (global vigor questionnaire), objective sleepiness (Multiple Sleep Latency Tests) and alertness (psychomotor vigilance task) were included in analyses. Independent samples t-tests and linear regressions were performed to identify group differences in sleepiness and nighttime sleep predictors of sleepiness in the overall sample and within each group. Participants with posttraumatic stress disorder had higher subjective sleepiness (t = 4.20; p < .001) and lower alertness (psychomotor vigilance task reaction time (t = -3.70; p < .001) and lapses: t = -2.13; p = .04) than the control group. Objective daytime sleepiness did not differ between groups (t = -0.79, p = .43). In the whole sample, higher rapid eye movement delta power predicted lower alertness quantified by psychomotor vigilance task reaction time (β = 0.372, p = .013) and lapses (β = 0.388, p = .013). More fragmented sleep predicted higher objective sleepiness in the posttraumatic stress disorder group (β = -.467, p = .005) but no other nighttime sleep measures influenced the relationship between group and sleepiness. Objective measures of sleep and sleepiness were not associated with the increased subjective sleepiness and reduced alertness of the posttraumatic stress disorder group.

Overnight Sleep Parameter Increases in Frontoparietal Areas Predict Working Memory Improvements in Healthy Participants But Not in Individuals With Posttraumatic Stress Disorder

BACKGROUND

Preliminary evidence indicates that non-rapid eye movement (NREM) sleep is implicated in enhancing working memory (WM) performance across days in healthy individuals. While REM sleep has been implicated in other forms of memory, its role in WM remains unclear. Further, the relationship between sleep changes and WM improvement is largely unknown in posttraumatic stress disorder (PTSD). Examining the relationship between changes in sleep and WM improvement in healthy participants and participants with PTSD may inform cognitive enhancement strategies and intervention targets.

METHODS

Repeated assessments of WM and overnight measurement of NREM and REM sleep parameters were performed in 79 participants (participants with PTSD: n = 33) during a 48-hour laboratory stay. Relationships between sleep parameter changes, WM performance changes, and clinical characteristics were analyzed in PTSD and healthy groups.

RESULTS

A between-night enhancement in both NREM and REM sleep parameters in frontoparietal areas predicted across-day better WM performance in healthy participants, particularly in those with improved performance. In contrast, in participants with PTSD, an enhancement of these sleep parameters predicted a worse WM performance and was also associated with more PTSD-related sleep disturbances.

CONCLUSIONS

This study shows that higher sleep activity in frontoparietal areas leads to enhanced WM performance in healthy individuals, whereas in individuals with PTSD, it likely reflects the presence of sleep disturbances that interfere with WM improvement. Interventions focused on addressing sleep disturbances could therefore ameliorate cognitive impairments in individuals with PTSD.

Strength and Temporal Variance of the Default Mode Network to Investigate Chronic Mild Traumatic Brain Injury in Service Members with Psychological Trauma

BACKGROUND

There is a significant number of military personnel with a history of mild traumatic brain injury (mTBI) who suffer from comorbid posttraumatic stress symptoms (PTS). Although there is evidence of disruptions of the default mode network (DMN) associated with PTS and mTBI, previous studies have only studied static connectivity while ignoring temporal variability of connectivity.

OBJECTIVE

To assess DMN disrupted or dysregulated neurocircuitry, cognitive functioning, and psychological health of active-duty military with mTBI and PTS.

METHOD

U.S. Army soldiers with PTS (n = 14), mTBI + PTS (n = 25), and healthy controls (n = 21) voluntarily completed a cognitive and symptom battery. In addition, participants had magnetic resonance imaging (MRI) to assess both static functional connectivity (SFC) and variance of dynamic functional connectivity (vDFC) of the DMN.

RESULTS

Both the PTS and mTBI + PTS groups had significant symptoms, but only the comorbid group had significant decrements in cognitive functioning. Both groups showed less stable and disrupted neural signatures of the DMN, mainly constituting the cingulate-frontal-temporal-parietal attention network. Specifically, the PTS group showed a combination of both reduced contralateral strength and reduced unilateral variability of frontal-cingulate-temporal connectivities, as well as increased variability of frontal-parietal connectivities. The mTBI + PTS group had fewer abnormal connectives than the PTS group, all of which included reduced strength of frontal-temporal regions and reduced variability frontal-cingulate-temporal regions. Greater SFC and vDFC connectivity of the left dorsolateral prefrontal cortex (dlPFC) ↔ precuneus was associated with higher cognitive scores and lower symptom scores.

CONCLUSIONS

Findings suggest that individuals with PTS and mTBI + PTS have a propensity for accentuated generation of thoughts, feelings, sensations, and/or images while in a resting state. Compared with controls, only the PTS group was associated with accentuated variability of the frontal-parietal attention network. While there were no significant differences in DMN connectivity strength between the mTBI + PTS and PTS groups, variability of connectivity was able to distinguish them.

Socioeconomic disparity in prefrontal development during early childhood

Socioeconomic status (SES) has a powerful influence on cognitive, social and brain development. Children from low-SES backgrounds show poor executive function (EF). However, it is unclear if there is a SES-dependent disparity in functional brain development. The present study examined whether the SES of preschool children (N = 93) is associated with prefrontal activation during cognitive shifting tasks as measured by near-infrared spectroscopy. Low-SES children did not show activation in lateral prefrontal regions during the tasks, whereas middle- and high-SES children showed prefrontal activations, although no differences were found in terms of behavioural performance. These results suggest that SES can affect the functional development of the prefrontal regions. In this study, we discuss the practical implications of the results.

Investigating the Correspondence of Clinical Diagnostic Grouping With Underlying Neurobiological and Phenotypic Clusters Using Unsupervised Machine Learning

Many brain-based disorders are traditionally diagnosed based on clinical interviews and behavioral assessments, which are recognized to be largely imperfect. Therefore, it is necessary to establish neuroimaging-based biomarkers to improve diagnostic precision. Resting-state functional magnetic resonance imaging (rs-fMRI) is a promising technique for the characterization and classification of varying disorders. However, most of these classification methods are supervised, i.e., they require a priori clinical labels to guide classification. In this study, we adopted various unsupervised clustering methods using static and dynamic rs-fMRI connectivity measures to investigate whether the clinical diagnostic grouping of different disorders is grounded in underlying neurobiological and phenotypic clusters. In order to do so, we derived a general analysis pipeline for identifying different brain-based disorders using genetic algorithm-based feature selection, and unsupervised clustering methods on four different datasets; three of them-ADNI, ADHD-200, and ABIDE-which are publicly available, and a fourth one-PTSD and PCS-which was acquired in-house. Using these datasets, the effectiveness of the proposed pipeline was verified on different disorders: Attention Deficit Hyperactivity Disorder (ADHD), Alzheimer's Disease (AD), Autism Spectrum Disorder (ASD), Post-Traumatic Stress Disorder (PTSD), and Post-Concussion Syndrome (PCS). For ADHD and AD, highest similarity was achieved between connectivity and phenotypic clusters, whereas for ASD and PTSD/PCS, highest similarity was achieved between connectivity and clinical diagnostic clusters. For multi-site data (ABIDE and ADHD-200), we report site-specific results. We also reported the effect of elimination of outlier subjects for all four datasets. Overall, our results suggest that neurobiological and phenotypic biomarkers could potentially be used as an aid by the clinician, in additional to currently available clinical diagnostic standards, to improve diagnostic precision. Data and source code used in this work is publicly available at https://github.com/xinyuzhao/identification-of-brain-based-disorders.git.

The impact of pre-existing anxiety on affective and cognitive processing of a Virtual Reality analogue trauma

Dysfunctional processing of traumatic events may be in particular related to high trait anxiety as a pre-traumatic risk factor for the development of post-traumatic stress disorder (PTSD). However, as this has rarely been investigated in prospective, experimental studies, we aimed to analyse the association between high trait anxiety and affective as well as cognitive processing of stress using a new prospective Virtual Reality analogue trauma paradigm to overcome limitations of retrospective or current analogue designs. Individuals with high and low trait anxiety (N = 80) were exposed to a multi-sensory Virtual Reality emergency scenario while psychophysiological stress response, emotion regulation and intrusive memories were assessed. Our results showed that high trait anxiety individuals display increased (i) subjective stress responses, (ii) emotion dysregulation and (iii) intrusive memories upon VR analogue trauma exposure. In particular, our sample of high trait anxiety individuals displayed limited access to different emotion regulation strategies as well as increased worry and rumination regarding perceived intrusive memories. Considering the complex interplay of multiple risk factors, our findings suggests that peri-traumatic affective processing seems to mediate high trait anxiety and post-traumatic intrusive memories thereby pointing out the central role of peri-traumatic processes for intrusion development. In addition, HA as a modulating pre-traumatic risk factor might further increase the risk of later dysfunctional processing of an analogue trauma by interacting with factors of affective processing during analogue trauma exposure. Implications of these findings which may contribute to a higher risk to develop PTSD are discussed.

Differential neural activation when voluntarily regulating emotions in service members with chronic mild traumatic brain injury

The objective of this study was to characterize the functional activation of the neural correlates of voluntary regulation of emotion in soldiers both with and without chronic mild traumatic brain injury (mTBI). Using functional magnetic resonance imaging (fMRI) and a battery of cognitive and psychological health measures, we assessed differences between active-duty U.S. soldiers with chronic mTBI (n = 37) and without (Controls, n = 35). Participants were instructed to maintain (passively view), enhance, and suppress emotions associated with negative and neutral visual stimuli. The mTBI group showed significantly greater clinical symptoms, but only a mild decrement in attention. Group contrasts, while controlling for posttraumatic stress disorder (PTSD) symptoms, revealed a differential neural activation pattern compared to controls, but only during the enhance condition. Specifically, the mTBI group showed greater activation in the precentral gyrus, postcentral gyrus, inferior parietal lobe, insula, and superior temporal gyrus. Finally, the effect of PTSD symptoms during the enhance condition was associated with accentuated activation of the frontal and limbic regions implicated in both emotion regulation and PTSD. Hyperactivation of neural regions in the mTBI group during the enhance condition may reflect vigilance towards negative contextual stimuli and/or poor strategy that might result in suboptimal allocation of resources to regulate emotions.

Anxiety Patients Show Reduced Working Memory Related dlPFC Activation During Safety and Threat

BACKGROUND

Anxiety patients exhibit deficits in cognitive tasks that require prefrontal control of attention, including those that tap working memory (WM). However, it is unclear whether these deficits reflect threat-related processes or symptoms of the disorder. Here, we distinguish between these hypotheses by determining the effect of shock threat versus safety on the neural substrates of WM performance in anxiety patients and healthy controls.

METHODS

Patients, diagnosed with generalized and/or social anxiety disorder, and controls performed blocks of an N-back WM task during periods of safety and threat of shock. We recorded blood-oxygen-level dependent (BOLD) activity during the task, and investigated the effect of clinical anxiety (patients vs. controls) and threat on WM load-related BOLD activation.

RESULTS

Behaviorally, patients showed an overall impairment in both accuracy and reaction time compared to controls, independent of threat. At the neural level, patients showed less WM load-related activation in the dorsolateral prefrontal cortex, a region critical for cognitive control. In addition, patients showed less WM load-related deactivation in the ventromedial prefrontal cortex and posterior cingulate cortex, which are regions of the default mode network. Most importantly, these effects were not modulated by threat.

CONCLUSIONS

This work suggests that the cognitive deficits seen in anxiety patients may represent a key component of clinical anxiety, rather than a consequence of threat.

A quantitative meta-analysis of neurocognitive functioning in posttraumatic stress disorder

Posttraumatic stress disorder (PTSD) is associated with regional alterations in brain structure and function that are hypothesized to contribute to symptoms and cognitive deficits associated with the disorder. We present here the first systematic meta-analysis of neurocognitive outcomes associated with PTSD to examine a broad range of cognitive domains and describe the profile of cognitive deficits, as well as modifying clinical factors and study characteristics. This report is based on data from 60 studies totaling 4,108 participants, including 1,779 with PTSD, 1,446 trauma-exposed comparison participants, and 895 healthy comparison participants without trauma exposure. Effect-size estimates were calculated using a mixed-effects meta-analysis for 9 cognitive domains: attention/working memory, executive functions, verbal learning, verbal memory, visual learning, visual memory, language, speed of information processing, and visuospatial abilities. Analyses revealed significant neurocognitive effects associated with PTSD, although these ranged widely in magnitude, with the largest effect sizes in verbal learning (d = -.62), speed of information processing (d = -.59), attention/working memory (d = -.50), and verbal memory (d =-.46). Effect-size estimates were significantly larger in treatment-seeking than community samples and in studies that did not exclude participants with attention-deficit/hyperactivity disorder, and effect sizes were affected by between-group IQ discrepancies and the gender composition of the PTSD groups. Our findings indicate that consideration of neuropsychological functioning in attention, verbal memory, and speed of information processing may have important implications for the effective clinical management of persons with PTSD. Results are further discussed in the context of cognitive models of PTSD and the limitations of this literature.

A quantitative meta-analysis of neurocognitive functioning in posttraumatic stress disorder

Posttraumatic stress disorder (PTSD) is associated with regional alterations in brain structure and function that are hypothesized to contribute to symptoms and cognitive deficits associated with the disorder. We present here the first systematic meta-analysis of neurocognitive outcomes associated with PTSD to examine a broad range of cognitive domains and describe the profile of cognitive deficits, as well as modifying clinical factors and study characteristics. This report is based on data from 60 studies totaling 4,108 participants, including 1,779 with PTSD, 1,446 trauma-exposed comparison participants, and 895 healthy comparison participants without trauma exposure. Effect-size estimates were calculated using a mixed-effects meta-analysis for 9 cognitive domains: attention/working memory, executive functions, verbal learning, verbal memory, visual learning, visual memory, language, speed of information processing, and visuospatial abilities. Analyses revealed significant neurocognitive effects associated with PTSD, although these ranged widely in magnitude, with the largest effect sizes in verbal learning (d = -.62), speed of information processing (d = -.59), attention/working memory (d = -.50), and verbal memory (d =-.46). Effect-size estimates were significantly larger in treatment-seeking than community samples and in studies that did not exclude participants with attention-deficit/hyperactivity disorder, and effect sizes were affected by between-group IQ discrepancies and the gender composition of the PTSD groups. Our findings indicate that consideration of neuropsychological functioning in attention, verbal memory, and speed of information processing may have important implications for the effective clinical management of persons with PTSD. Results are further discussed in the context of cognitive models of PTSD and the limitations of this literature.

Genetic approaches to understanding post-traumatic stress disorder

Post-traumatic stress disorder (PTSD) is increasingly recognized as both a disorder of enormous mental health and societal burden, but also as an anxiety disorder that may be particularly understandable from a scientific perspective. Specifically, PTSD can be conceptualized as a disorder of fear and stress dysregulation, and the neural circuitry underlying these pathways in both animals and humans are becoming increasingly well understood. Furthermore, PTSD is the only disorder in psychiatry in which the initiating factor, the trauma exposure, can be identified. Thus, the pathophysiology of the fear and stress response underlying PTSD can be examined and potentially interrupted. Twin studies have shown that the development of PTSD following a trauma is heritable, and that genetic risk factors may account for up to 30-40% of this heritability. A current goal is to understand the gene pathways that are associated with PTSD, and how those genes act on the fear/stress circuitry to mediate risk vs. resilience for PTSD. This review will examine gene pathways that have recently been analysed, primarily through candidate gene studies (including neuroimaging studies of candidate genes), in addition to genome-wide associations and the epigenetic regulation of PTSD. Future and on-going studies are utilizing larger and collaborative cohorts to identify novel gene candidates through genome-wide association and other powerful genomic approaches. Identification of PTSD biological pathways strengthens the hope of progress in the mechanistic understanding of a model psychiatric disorder and allows for the development of targeted treatments and interventions.

Childhood trauma and PTSD symptoms increase the risk of cognitive impairment in a sample of former indentured child laborers in old age

A growing body of evidence suggests a link between early childhood trauma, post-traumatic stress disorder (PTSD) and higher risk for dementia in old age. The aim of the present study was to investigate the association between childhood trauma exposure, PTSD and neurocognitive function in a unique cohort of former indentured Swiss child laborers in their late adulthood. To the best of our knowledge this is the first study ever conducted on former indentured child laborers and the first to investigate the relationship between childhood versus adulthood trauma and cognitive function. According to PTSD symptoms and whether they experienced childhood trauma (CT) or adulthood trauma (AT), participants (n = 96) were categorized as belonging to one of four groups: CT/PTSD+, CT/PTSD-, AT/PTSD+, AT/PTSD-. Information on cognitive function was assessed using the Structured Interview for Diagnosis of Dementia of Alzheimer Type, Multi-infarct Dementia and Dementia of other Etiology according to ICD-10 and DSM-III-R, the Mini-Mental State Examination, and a vocabulary test. Depressive symptoms were investigated as a potential mediator for neurocognitive functioning. Individuals screening positively for PTSD symptoms performed worse on all cognitive tasks compared to healthy individuals, independent of whether they reported childhood or adulthood adversity. When controlling for depressive symptoms, the relationship between PTSD symptoms and poor cognitive function became stronger. Overall, results tentatively indicate that PTSD is accompanied by cognitive deficits which appear to be independent of earlier childhood adversity. Our findings suggest that cognitive deficits in old age may be partly a consequence of PTSD or at least be aggravated by it. However, several study limitations need to considered. Consideration of cognitive deficits when treating PTSD patients and victims of lifespan trauma (even without a diagnosis of a psychiatric condition) is crucial. Furthermore, early intervention may prevent long-term deficits in memory function and development of dementia in adulthood.