Associations Among Childhood Trauma, Childhood Mental Disorders, and Past-Year Posttraumatic Stress Disorder in Military and Civilian Men

High executive functioning is associated with reduced posttraumatic stress after trauma exposure among male U.S. military personnel

Introduction

Evidence suggests that executive function (EF) may play a key role in development of PTSD, possibly influenced by factors such as trauma type and timing. Since EF can be improved through intervention, it may be an important target for promoting resilience to trauma exposure. However, more research is needed to understand the relation between trauma exposure, EF, and PTSD. The goal of this study was to improve understanding of EF as a potential antecedent or protective factor for the development of PTSD among military personnel.

Method

In a cohort of U.S. Marines and Navy personnel (N = 1,373), the current study tested the association between exposure to traumatic events (pre-deployment and during deployment) and PTSD severity, and whether EF moderated these associations. Three types of pre-deployment trauma exposure were examined: cumulative exposure, which included total number of events participants endorsed as having happened to them, witnessed, or learned about; direct exposure, which included total number of events participants endorsed as having happened to them; and interpersonal exposure, which included total number of interpersonally traumatic events participants' endorsed. EF was measured using the Penn Computerized Neurocognitive Battery.

Results

EF was associated with less PTSD symptom severity at pre-deployment, even when adjusting for trauma exposure, alcohol use, traumatic brain injury, and number of years in the military. EF also moderated the relation between cumulative trauma exposure and interpersonal trauma exposure and PTSD, with higher EF linked to a 20 and 33% reduction in expected point increase in PTSD symptoms with cumulative and interpersonal trauma exposure, respectively. Finally, higher pre-deployment EF was associated with reduced PTSD symptom severity at post-deployment, independent of deployment-related trauma exposure and adjusting for pre-deployment PTSD.

Conclusion

Our results suggest that EF plays a significant, if small role in the development of PTSD symptoms after trauma exposure among military personnel. These findings provide important considerations for future research and intervention and prevention, specifically, incorporating a focus on improving EF in PTSD treatment.

Childhood Trauma Differentially Impacts Depression and Stress Associations with Reintegration Challenges Among Post-9/11 U.S. Veterans

BACKGROUND

Post-9/11 veterans exhibit high prevalence of deployment stress, psychological conditions, and traumatic brain injury (TBI) which impact reintegration, especially among those with a history of interpersonal early life trauma (I-ELT). The relative importance of each risk factor is unclear.

PURPOSE

We examined major deployment and clinical exposures of reintegration challenges among veterans with and without I-ELT.

METHOD

We analyzed cross-sectional data of 155 post-9/11 veterans from the Translational Research Center for TBI and Stress Disorders study.

FINDINGS

Depression severity had the strongest association with reintegration challenges, followed by posttraumatic stress disorder (PTSD) severity, post-deployment stress, and deployment safety concerns. Deployment safety concerns had a stronger, significant association among veterans with I-ELT. In nearly every model, PTSD and depression severities were weaker for veterans with I-ELT, compared to those without.

DISCUSSION

Clinicians should consider the relative risk of concurrent clinical conditions and trauma histories when considering veterans' reintegration needs.

Childhood determinants of past-year anxiety and depression in recently transitioned military personnel

BACKGROUND

Anxiety and depression may hamper a smooth transition from military to civilian life and may be important predictors of longer-term health and functioning. However, it is as yet unclear to what extent they are determined by childhood factors in a recently transitioned population.

METHODS

We utilised logistic regression and Generalised Structural Equation Modelling to analyse associations of ICD-10 past-year anxiety and depression with childhood trauma and disorder in a recently transitioned population using detailed interview data from the ADF (Australian Defence Force) Transition and Wellbeing Research Programme.

RESULTS

Past-year anxiety (including PTSD) was prevalent (36.4%, 95% CI, 31.9-41.1) and associated with childhood anxiety (but not other types of childhood disorder), childhood interpersonal trauma (but not other childhood trauma) and adult-onset trauma. Childhood anxiety had a direct and significant association with past-year anxiety. The pathway between childhood interpersonal trauma and past-year anxiety was fully mediated by childhood anxiety. Past-year depression was less prevalent (11.3%, 95% CI, 8.7-14.5) and had no association with childhood disorder or trauma variables.

LIMITATIONS

The main predictor variables utilized in this analysis were childhood experiences recalled from adulthood, thus rendering the responses vulnerable to autobiographical bias.

CONCLUSIONS

Past-year anxiety was highly prevalent in the period of transition and had strong associations with childhood and military factors, suggesting predictability and potentially preventability.

Childhood determinants of suicidality in men recently transitioned from regular military service

OBJECTIVE

Rates of suicidality are higher in military than comparable civilian populations. The period of transition from regular military service may be a time of particular vulnerability. In order to best inform early intervention and prevention strategies, we sought to investigate the childhood determinants (trauma and disorder) of self-reported past-year suicidality (thoughts, plans or attempts) in a population of Australian Defence Force men who had recently (in the previous 5 years) transitioned from regular military service.

METHODS

We analysed self-report, and detailed interview, cross-sectional data to investigate the association between retrospectively reported past-year suicidality and childhood factors (disorder and trauma) and whether these relationships were independent of each other and adult-onset trauma and disorder. We utilised logistic regression techniques and generalised structural equation modelling.

RESULTS

The prevalence of suicidality in transitioned men was 21.6% (95% confidence interval [CI]: [19.9, 23.3]). Suicidality was associated with childhood-onset interpersonal trauma and anxiety and adult-onset anxiety and depression. Generalised structural equation modelling demonstrated that the pathway between childhood interpersonal trauma and suicidality was not fully mediated by childhood anxiety. Restricting the analyses to those previously deployed demonstrated that suicidality had a direct and significant association with childhood-onset factors (anxiety and interpersonal trauma) and adult-onset trauma (deployment and non-deployment related).

CONCLUSION

This study sheds light onto the significance of childhood factors (interpersonal trauma and anxiety) in a population undergoing transition that may revive pre-existing vulnerabilities. These findings have the potential to aid early intervention and prevention strategies in identifying those at risk prior to transition. These findings also imply that early interventions targeting anxiety and interventions to reduce social instability during the transition period may be useful in reducing suicidality during this time. Further prospective studies are needed to further explore these novel findings.

Splice-specific deficiency of the PTSD-associated gene PAC1 leads to a paradoxical age-dependent stress behavior

The pituitary adenylate cyclase-activating polypeptide receptor (PAC1, also known as ADCYAP1R1) is associated with post-traumatic stress disorder and modulation of stress response in general. Alternative splicing of PAC1 results in multiple gene products, which differ in their mode of signalling and tissue distribution. However, the roles of distinct splice variants in the regulation of stress behavior is poorly understood. Alternative splicing of a short exon, which is known as the "hop cassette", occurs during brain development and in response to stressful challenges. To examine the function of this variant, we generated a splice-specific zebrafish mutant lacking the hop cassette, which we designated 'hopless'. We show that hopless mutant larvae display increased anxiety-like behavior, including reduced dark exploration and impaired habituation to dark exposure. Conversely, adult hopless mutants displayed superior ability to rebound from an acute stressor, as they exhibited reduced anxiety-like responses to an ensuing novelty stress. We propose that the developmental loss of a specific PAC1 splice variant mimics prolonged mild stress exposure, which in the long term, predisposes the organism's stress response towards a resilient phenotype. Our study presents a unique genetic model demonstrating how early-life state of anxiety paradoxically correlates with reduced stress susceptibility in adulthood.

Splice-specific deficiency of the PTSD-associated gene PAC1 leads to a paradoxical age-dependent stress behavior

The pituitary adenylate cyclase-activating polypeptide receptor (PAC1, also known as ADCYAP1R1) is associated with post-traumatic stress disorder and modulation of stress response in general. Alternative splicing of PAC1 results in multiple gene products, which differ in their mode of signalling and tissue distribution. However, the roles of distinct splice variants in the regulation of stress behavior is poorly understood. Alternative splicing of a short exon, which is known as the "hop cassette", occurs during brain development and in response to stressful challenges. To examine the function of this variant, we generated a splice-specific zebrafish mutant lacking the hop cassette, which we designated 'hopless'. We show that hopless mutant larvae display increased anxiety-like behavior, including reduced dark exploration and impaired habituation to dark exposure. Conversely, adult hopless mutants displayed superior ability to rebound from an acute stressor, as they exhibited reduced anxiety-like responses to an ensuing novelty stress. We propose that the developmental loss of a specific PAC1 splice variant mimics prolonged mild stress exposure, which in the long term, predisposes the organism's stress response towards a resilient phenotype. Our study presents a unique genetic model demonstrating how early-life state of anxiety paradoxically correlates with reduced stress susceptibility in adulthood.