Child abuse interacts with hippocampal and corpus callosum volume on psychophysiological response to startling auditory stimuli in a sample of veterans

Impact of adverse childhood experience on physical and mental health: A life-course epidemiology perspective

Adverse childhood experiences (ACEs) have been shown to have long-term effects on physical and mental health, not only in the US, but also other countries, including Japan. In this paper, measurement of assessment of ACEs has been discussed, that is, concept (what is ACEs), inquiry (how to ask about ACEs), scoring (how to count the number of ACEs), and prevalence (how many ACEs do we have). In addition, a possible mechanism on how ACEs affect health was summarized from a life-course perspective, using the critical/sensitive period model, pathway model, and cumulative model with recent evidence on neurological findings. Intergenerational transmission, that is, maternal ACEs affecting the health of the offspring was also reviewed. Finally, future directions on how to prevent and remedy the impact of ACEs on health was discussed.

Ventromedial and insular cortical volume moderates the relationship between BDNF Val66Met and threat sensitivity

While the BDNF Val66Met polymorphism has been linked to various trauma and anxiety - related psychiatric disorders, limited focus has been on the neural structures that might modulate its relationship with objective measures of threat sensitivity. Therefore, we assessed whether there was an interaction of Val66Met polymorphism with brain area volumes previously associated with anxiety and PTSD, such as the ventromedial prefrontal cortex (vmPFC), insular cortex (IC), and dorsal and ventral anterior cingulate cortices (dACC and vACC), in predicting fear-potentiated psychophysiological response in a clinical sample of Veterans. 110 participants engaged in a fear-potentiated acoustic startle paradigm and provided genetic and imaging data. Fear conditions included no, ambiguous, and high threat conditions (shock). Psychophysiological response measures included electromyogram (EMG), skin conductance response (SCR), and heart rate (HR). PTSD status, trauma history, and demographics were also assessed. There was an interaction of Met allele carrier status with vmPFC, IC, dACC, and vACC volumes for predicting SCR (p < 0.001 for all regions). However, only vmPFC and IC significantly moderated the relationship between Val66Met and psychophysiological response (SCR). The Val66met polymorphism may increase susceptibility to PTSD and anxiety disorders via an interaction with reduced vmPFC and IC volume. Future research should examine whether these relationships might be associated with a differential course of illness longitudinally or response to treatments.

Mediation on the Association Between Stressful Life Events and Depression by Abnormal White Matter Microstructures

BACKGROUND

Stressful life events (SLEs) are an important causal factor in depression; however, the mechanism by which SLEs cause depression remains unclear. Recent studies suggested that white matter (WM) microstructures might be a potential mediator between SLEs and depression. Hence, we aimed to investigate the concrete correspondence among them using mediation effect models.

METHODS

In participants (N = 194) with SLEs experience prospectively recruited from six residential communities, WM microstructures were detected with diffusion tensor imaging. The interrelationship among SLEs, WM microstructures, and depression was explored with multiple linear regression models and logistic regression models. Furthermore, the influence of WM microstructures on the association between SLEs and depression was tested with mediation effect models.

RESULTS

Successfully established mediation effect models showed the specific influence of fractional anisotropy of the corpus callosum and left uncinate fasciculus on the association between SLEs and depression onset (ab path = 0.032; ab path = 0.026, respectively) and between SLEs and depressive severity (ab path = 0.052; ab path = 0.067, respectively). In addition, significant total mediation effects on the association between SLEs and depression onset (ab path = 0.031) and severity (ab path = 0.075) through fractional anisotropy of the corpus callosum and left uncinate fasciculus were noted.

CONCLUSIONS

WM microstructure alterations impose a substantial mediation effect on the association between SLEs and depression, which suggest that changes in WM microstructure integrity might increase the risk of depression onset and unfavorable disease courses induced by the SLEs.

Impulsivity as a multifactorial construct and its relationship to PTSD severity and threat sensitivity

Changes to the DSM-5's conceptualization of posttraumatic stress disorder (PTSD) highlight the importance of impulsivity within the context of PTSD-related arousal dysregulation. While the relationship between PTSD and threat sensitivity is well defined, how they relate to impulsivity remains understudied. We examined the relationship between PTSD symptom severity, threat sensitivity, and impulsivity. 124 participants completed the PTSD Checklist (PCL-C) and the Barratt Impulsiveness Scale 11th ed (BIS-11). BIS-11 items were separated to define cognitive and behavioral impulsivity subdomains. A trauma-exposed subsample of 39 participants were also exposed to no, ambiguous, and high threat conditions in a threat-enhanced acoustic startle paradigm with psychophysiological response as the outcome variable. PTSD severity was significantly associated with greater overall impulsivity and behavioral impulsivity. Greater overall impulsivity and both cognitive and behavioral impulsivity subdomains were significantly associated with psychophysiological magnitudes across threat conditions in the traumatized subsample. Our results suggest PTSD severity may linked to behavioral impulsivity and both cognitive and behavioral impulsivity are associated with threat sensitivity and hyperarousal. Assessing impulsivity within the context of PTSD, particularly in terms of its cognitive and behavioral subdomains, may provide important, clinically relevant information.