CHILDHOOD MALTREATMENT PREDICTS REDUCED INHIBITION-RELATED ACTIVITY IN THE ROSTRAL ANTERIOR CINGULATE IN PTSD, BUT NOT TRAUMA-EXPOSED CONTROLS

Cross-sectional study of retrospective self-reported childhood emotional neglect and inhibitory neurometabolite levels in the pregenual anterior cingulate cortex in adult humans

High childhood emotional maltreatment (CM-EMO) is reported in mood and anxiety disorders. The associations with an increased risk for psychopathology are not fully understood. One potential factor may be through alterations in gamma-Aminobutyric acid (GABA). The pregenual anterior cingulate cortex (pgACC) is an important brain region for emotion processing and its' GABA levels were previously implicated in mood and anxiety disorders pathophysiology. We examined the association between the self-reported CM-EMO in adulthood and GABA + levels in the pgACC and in a control region, anterior mid cingulate cortex. GABA+ and total creatine (tCr) were measured in the pgACC and aMCC voxels in seventy-four healthy volunteers (32 (43%) women, ages 19-54, age [standard deviation] = 27.1 [6.5]) using proton magnetic resonance spectroscopy at 7 T. Childhood Trauma Questionnaire was completed by adult participants to measure retrospective self-reported experience of emotional neglect (CM-EMO-NEG) and emotional abuse (CM-EMO-AB) during childhood. Linear mixed models tested the interaction between the region and the two subscales, and GABA+/tCr ratios, with an adjusted alpha = 0.025. Following, linear models, including with covariates were tested. There was an interaction effect between region and CM-EMO-NEG (B = -0.007, p = 0.009), driven by a negative relationship between CM-EMO-NEG and GABA+/tCr in the pgACC (B = -0.004, p = 0.013). Results for CM-EMO-NEG were robust to inclusion of different covariates (ps < 0.035). There was no interaction effect for the CM-EMO-AB (B = 0.007, p = 0.4). Limitations include cross-sectional measurement and retrospective nature of the CTQ. The findings indicate preliminary importance of inhibitory neurometabolite concentrations in the pgACC for retrospective reporting of CM-EMO-NEG.

Regional specificity and clinical correlates of cortical GABA alterations in posttraumatic stress disorder

Gamma-aminobutyric acid (GABA) metabolism is implicated in posttraumatic stress disorder (PTSD) and may be altered in prefrontal-limbic brain regions involved in arousal regulation. This study used proton magnetic resonance spectroscopy (MRS) to test the hypothesis that PTSD and trauma-exposed non-PTSD comparison (TENC) adults have significantly different GABA than healthy comparison (HC) subjects in two brain areas implicated in arousal (medial prefrontal cortex, insula) but not in a control brain area (posterior temporal cortex). We also examined whether GABA alterations correlated with hyperarousal and dissociation symptoms. One hundred and fourteen participants (39 PTSD, 34 TENC, 41 HC) underwent 3T MRS of the medial prefrontal, right insular, and right posterior temporal cortices, and the GABA plus macromolecule signal (GABA+) was normalized to creatine (Cr). The Clinician Administered PTSD Scale measured hyperarousal symptoms, including sleep disruption. The Dissociative Experiences Scale assessed dissociation symptoms. PTSD and TENC participants had significantly lower mPFC GABA+/Cr than HC participants, and this deficit was significantly correlated with greater dissociation. Compared with HC, PTSD patients but not TENC had significantly lower insula GABA+/Cr. Total hyperarousal symptoms and sleep disruption were not significantly associated with GABA+/Cr alterations in either region. Our findings point to lower GABA in cortical areas implicated in arousal regulation in PTSD and suggest that GABA alterations are associated with symptoms of trauma-related psychopathology but not always a biomarker of diagnosis. These findings also add to evidence that dissociation has distinct neural correlates within PTSD, including high excitability of medial prefrontal cortex.

Childhood maltreatment and its role in the development of pain and psychopathology

Childhood maltreatment represents a form of trauma capable of altering fundamental neurobiological properties and negatively impacting neurodevelopmental processes. An outcome of childhood maltreatment is the emergence of psychopathology, which might become evident during childhood or adolescence, but might also project into adulthood. In this Review, we propose a biobehavioural framework in which childhood maltreatment and the associated aberrant neurobiological mechanisms and behavioural processes additionally lead to the onset of altered pain processing and, ultimately, the existence of pain syndromes. Considering that subpopulations of maltreated children show preserved function and minimal psychiatric or pain symptoms, compensatory mechanisms-perhaps instilled by robust psychosocial support systems-are also discussed. We present validated tools and experimental methods that could facilitate better comprehension of the interactions between childhood maltreatment, psychopathology, and pain. Such tools and approaches can in parallel be implemented to monitor abnormal pain-related processes and potentially guide early intervention strategies in cases of childhood maltreatment.

Right inferior frontal gyrus and ventromedial prefrontal activation during response inhibition is implicated in the development of PTSD symptoms

Background

Inhibition is a critical executive control process and an established neurobiological phenotype of PTSD, yet to our knowledge, no prospective studies have examined this using a contextual cue task that enables measurement of behavioural response and neural activation patterns across proactive and reactive inhibition.

Objective

The current longitudinal study utilised functional magnetic resonance imaging (fMRI) to examine whether deficits in proactive and reactive inhibition predicted PTSD symptoms six months after trauma.

Method

Twenty-three (65% males) medical patients receiving emergency medical care from a level 1 trauma centre were enrolled in the study and invited for an MRI scan 1-2-months post-trauma. PTSD symptoms were measured using self-report at scan and 6-months post-trauma. A stop-signal anticipation task (SSAT) during an fMRI scan was used to test whether impaired behavioural proactive and reactive inhibition, and reduced activation in right inferior frontal gyrus (rIFG), ventromedial prefrontal cortex (vmPFC), and bilateral hippocampus, were related to PTSD symptoms. We predicted that lower activation levels of vmPFC and rIFG during reactive inhibition and lower activation of hippocampus and rIFG during proactive inhibition would relate to higher 6-month PTSD symptoms.

Results

No significant associations were found between behavioural measures and 6-month PTSD. Separate linear regression analyses showed that reduced rIFG activation (F_1,21= 9.97, R²= .32, p = .005) and reduced vmPFC activation (F_1,21= 5.19, R²= .20, p = .03) significantly predicted greater 6-month PTSD symptoms; this result held for rIFG activation controlling for demographic variables and baseline PTSD symptoms (β = -.45, p = .04) and Bonferroni correction.

Conclusion

Our findings suggest that impaired rIFG and, to a lesser extent, vmPFC activation during response inhibition may predict the development of PTSD symptoms following acute trauma exposure. Given the small sample size, future replication studies are needed.

HIGHLIGHTS

Impaired inhibition may be an important risk factor for the development of PTSD following trauma, with less right inferior frontal gyrus and ventromedial prefrontal cortex activation during response inhibition predicting PTSD development.

Mapping structural covariance networks in children and adolescents with post-traumatic stress disorder after earthquake

For children and adolescents, there is a high risk of developing post-traumatic stress disorder (PTSD) after suffering from catastrophic events. Previous studies have identified brain functionally and subcortical brain volumes structurally abnormalities in this population. However, up till now, researches exploring alterations of regional cortical thickness (CTh) and brain interregional structural covariance networks (SCNs) are scarce. In this cross-sectional study, CTh measures are derived from 3-Tesla Tl-weighted MRI imaging data in a well-characterized combined group of children and adolescents with PTSD after an earthquake (N = 35) and a traumatized healthy control group (N = 24). By using surface-based morphometry (SBM) techniques, the regional CTh analysis was conducted. To map interregional SCNs derived from CTh, twenty-five altered brain regions reported in the PTSD population were selected as seeds. Whole-brain SBM analysis discovered a significant thickness reduction in the left medial orbitofrontal cortex for the subjects with PTSD. Similarly, analysis of SCNs associated with "seed" regions primarily located in default mode network (DMN), midline cortex structures, motor cortex, auditory association cortex, limbic system, and visual cortex demonstrated that children and adolescents with PTSD are associated with altered structural covariance with six key regions. This study provides evidence for distinct CTh correlates of PTSD that are present across children and adolescents, suggesting that brain cortical abnormalities related to trauma exposure are present in this population, probably by driving specific symptom clusters associated with disrupted extinction recall mechanisms for fear, episodic memory network and visuospatial attention.

Prefrontal cortex, amygdala, and threat processing: implications for PTSD

Posttraumatic stress disorder can be viewed as a disorder of fear dysregulation. An abundance of research suggests that the prefrontal cortex is central to fear processing-that is, how fears are acquired and strategies to regulate or diminish fear responses. The current review covers foundational research on threat or fear acquisition and extinction in nonhuman animals, healthy humans, and patients with posttraumatic stress disorder, through the lens of the involvement of the prefrontal cortex in these processes. Research harnessing advances in technology to further probe the role of the prefrontal cortex in these processes, such as the use of optogenetics in rodents and brain stimulation in humans, will be highlighted, as well other fear regulation approaches that are relevant to the treatment of posttraumatic stress disorder and involve the prefrontal cortex, namely cognitive regulation and avoidance/active coping. Despite the large body of translational research, many questions remain unanswered and posttraumatic stress disorder remains difficult to treat. We conclude by outlining future research directions related to the role of the prefrontal cortex in fear processing and implications for the treatment of posttraumatic stress disorder.

Migration-related trauma and mental health among migrant children emigrating from Mexico and Central America to the United States: Effects on developmental neurobiology and implications for policy

Children make up over half of the world's migrants and refugees and face a multitude of traumatic experiences prior to, during, and following migration. Here, we focus on migrant children emigrating from Mexico and Central America to the United States and review trauma related to migration, as well as its implications for the mental health of migrant and refugee children. We then draw upon the early adversity literature to highlight potential behavioral and neurobiological sequalae of migration-related trauma exposure, focusing on attachment, emotion regulation, and fear learning and extinction as transdiagnostic mechanisms underlying the development of internalizing and externalizing symptomatology following early-life adversity. This review underscores the need for interdisciplinary efforts to both mitigate the effects of trauma faced by migrant and refugee youth emigrating from Mexico and Central America and, of primary importance, to prevent child exposure to trauma in the context of migration. Thus, we conclude by outlining policy recommendations aimed at improving the mental health of migrant and refugee youth.

Transcriptome-wide association study of post-trauma symptom trajectories identified GRIN3B as a potential biomarker for PTSD development

Biomarkers that predict symptom trajectories after trauma can facilitate early detection or intervention for posttraumatic stress disorder (PTSD) and may also advance our understanding of its biology. Here, we aimed to identify trajectory-based biomarkers using blood transcriptomes collected in the immediate aftermath of trauma exposure. Participants were recruited from an Emergency Department in the immediate aftermath of trauma exposure and assessed for PTSD symptoms at baseline, 1, 3, 6, and 12 months. Three empirical symptom trajectories (chronic-PTSD, remitting, and resilient) were identified in 377 individuals based on longitudinal symptoms across four data points (1, 3, 6, and 12 months), using latent growth mixture modeling. Blood transcriptomes were examined for association with longitudinal symptom trajectories, followed by expression quantitative trait locus analysis. GRIN3B and AMOTL1 blood mRNA levels were associated with chronic vs. resilient post-trauma symptom trajectories at a transcriptome-wide significant level (N = 153, FDR-corrected p value = 0.0063 and 0.0253, respectively). We identified four genetic variants that regulate mRNA blood expression levels of GRIN3B. Among these, GRIN3B rs10401454 was associated with PTSD in an independent dataset (N = 3521, p = 0.04). Examination of the BrainCloud and GTEx databases revealed that rs10401454 was associated with brain mRNA expression levels of GRIN3B. While further replication and validation studies are needed, our data suggest that GRIN3B, a glutamate ionotropic receptor NMDA type subunit-3B, may be involved in the manifestation of PTSD. In addition, the blood mRNA level of GRIN3B may be a promising early biomarker for the PTSD manifestation and development.

The roles of attachment and emotion dysregulation in the association between childhood maltreatment and PTSD in an inner-city sample

BACKGROUND

Most people will experience a traumatic event in their lifetime, but only a subset (<10%) will develop posttraumatic stress disorder (PTSD).

OBJECTIVE

To facilitate prevention and intervention of PTSD, it is important to understand how risk and resilience factors interact with one another to explain individual differences in risk for PTSD, especially in underprivileged groups, who often experience greater burden of trauma and PTSD.

METHOD

The current study utilized multiple and moderated regression to examine the relation between childhood maltreatment and adulthood PTSD risk in the context of various attachment patterns and emotion dysregulation in a sample (n = 856) of mostly low-income, African American participants.

RESULTS

Moderation analysis indicated that the strongest association between self-reported childhood maltreatment and PTSD symptoms was manifest in participants reporting the highest levels of both attachment anxiety and attachment avoidance (b = 0.22, 95% CI [0.15, 0.29], p < .001), whereas, among those low on both these dimensions (i.e., more securely attached participants), there was no significant association between childhood maltreatment and current PTSD (b = 0.07, 95% CI [-0.01, 0.14], p = .07). Separately, multiple regression predicting current PTSD symptoms revealed an effect size for the two attachment dimensions similar to that of emotion dysregulation, while controlling for childhood maltreatment.

CONCLUSIONS

These findings suggest more secure attachment may buffer against the deleterious effects of childhood maltreatment, and both attachment difficulties and emotion dysregulation serve as robust correlates of adulthood PTSD.

Characterisation of self-defining memories in criminals with antisocial personality disorder

Early aversive events are key factors in the development of antisocial personality disorder (ASPD) and are known to impact the ability to produce specific autobiographical memories and to modify self-construction. The present study assessed identity construction in forensic inpatients suffering from ASPD by comparing the characteristics (specificity, integration, valence, topic and period) of self-defining memories (SDM) of persons with ASPD hospitalised in a forensic hospital to those of control participants. Offenders with ASPD had difficulty in retrieving purely specific single events and tended to recall memories comprising multiple events. In addition, they produced significantly less meaning-making from their past experiences (low integration). These characteristics of SDM could be due to a defensive process used by offenders with ASPD in which they do not integrate aversive experiences, thereby creating a vicious circle where maladjustment of their personality is maintained.

Increased activation of the fear neurocircuitry in children exposed to violence

Most studies investigating the effect of childhood trauma on the brain are retrospective and mainly focus on maltreatment, whereas different types of trauma exposure such as growing up in a violent neighborhood, as well as developmental stage, could have differential effects on brain structure and function. The current magnetic resonance imaging study assessed the effect of trauma exposure broadly and violence exposure more specifically, as well as developmental stage on the fear neurocircuitry in 8- to 14-year-old children and adolescents (N = 69). We observed reduced hippocampal and increased amygdala volume with increasing levels of trauma exposure. Second, higher levels of violence exposure were associated with increased activation in the amygdala, hippocampus, and ventromedial prefrontal cortex during emotional response inhibition. This association was specifically observed in children younger than 10 years. Finally, increased functional connectivity between the amygdala and brainstem was associated with higher levels of violence exposure. Based on the current findings, it could be hypothesized that trauma exposure during childhood results in structural changes that are associated with later risk for psychiatric disorders. At the same time, it could be postulated that growing up in an unsafe environment leads the brain to functionally adapt to this situation in a way that promotes survival, where the long-term costs or consequences of these adaptations are largely unknown and an area for future investigations.

The complex neurobiology of resilient functioning after childhood maltreatment

BACKGROUND

Childhood maltreatment has been associated with significant impairment in social, emotional and behavioural functioning later in life. Nevertheless, some individuals who have experienced childhood maltreatment function better than expected given their circumstances.

MAIN BODY

Here, we provide an integrated understanding of the complex, interrelated mechanisms that facilitate such individual resilient functioning after childhood maltreatment. We aim to show that resilient functioning is not facilitated by any single 'resilience biomarker'. Rather, resilient functioning after childhood maltreatment is a product of complex processes and influences across multiple levels, ranging from 'bottom-up' polygenetic influences, to 'top-down' supportive social influences. We highlight the complex nature of resilient functioning and suggest how future studies could embrace a complexity theory approach and investigate multiple levels of biological organisation and their temporal dynamics in a longitudinal or prospective manner. This would involve using methods and tools that allow the characterisation of resilient functioning trajectories, attractor states and multidimensional/multilevel assessments of functioning. Such an approach necessitates large, longitudinal studies on the neurobiological mechanisms of resilient functioning after childhood maltreatment that cut across and integrate multiple levels of explanation (i.e. genetics, endocrine and immune systems, brain structure and function, cognition and environmental factors) and their temporal interconnections.

CONCLUSION

We conclude that a turn towards complexity is likely to foster collaboration and integration across fields. It is a promising avenue which may guide future studies aimed to promote resilience in those who have experienced childhood maltreatment.

Childhood adversity, externalizing behavior, and substance use in adolescence: Mediating effects of anterior cingulate cortex activation during inhibitory errors

Childhood adversity can negatively impact development across various domains, including physical and mental health. Adverse childhood experiences have been linked to aggression and substance use; however, developmental pathways to explain these associations are not well characterized. Understanding early precursors to later problem behavior and substance use can inform preventive interventions. The aim of the current study was to examine neurobiological pathways through which childhood adversity may lead to early adolescent problem behavior and substance use in late adolescence by testing two prospective models. Our first model found that early adolescent externalizing behavior mediates the association between childhood adversity and alcohol, cigarette, and marijuana use in late adolescence. Our second model found that activation in the anterior cingulate cortex (ACC) during an inhibitory control task mediates the association between childhood adversity and early adolescent externalizing behavior, with lower ACC activation associated with higher levels of adversity and more externalizing behavior. Together these findings indicate that the path to substance use in late adolescence from childhood adversity may operate through lower functioning in the ACC related to inhibitory control and externalizing behavior. Early life stressors should be considered an integral component in the etiology and prevention of early and problematic substance use.

Neural Mechanisms of Spatial Attention Deficits in Trauma

BACKGROUND

Survival requires effective shifting of attention from one stimulus to another as goals change. It has been consistently demonstrated that posttraumatic stress disorder (PTSD) is associated with both faster orienting of attention toward and slower disengagement of attention from affective stimuli. Prior work, however, suggests that attention abnormalities in PTSD may extend beyond the affective domain.

METHODS

We used the Attention Network Test-modified to include invalid spatial cues-in conjunction with functional magnetic resonance imaging to examine the neurocognitive underpinnings of visuospatial attention in participants with PTSD (n = 31) and control participants who were (n = 20) and were not (n = 21) exposed to trauma.

RESULTS

We observed deficits in the utilization of spatial information in the group with PTSD. Specifically, compared with the non-trauma-exposed group, participants with PTSD showed a smaller reaction time difference between invalidly and validly cued targets, demonstrating that they were less likely to use spatial cues to inform subsequent behavior. We also found that in both the PTSD and trauma-exposed control groups, utilization of spatial information was positively associated with activation of attentional control regions (e.g., right precentral gyrus, inferior and middle frontal gyri) and negatively associated with activation in salience processing regions (e.g., right insula).

CONCLUSIONS

This pattern suggests that both trauma exposure and psychopathology may be associated with alterations of spatial attention. Overall, our findings suggest that both attention- and salience-network abnormalities may be related to altered attention in trauma-exposed populations. Treatments that target these neural networks could therefore be a new avenue for PTSD research.

Sex-dependent associations of childhood neglect and bodyweight across the life span

Eating disorders and weight problems across the life span have been linked to adverse childhood experiences. Previous research often focused on child abuse and omitted investigating effects of child neglect. The present study evaluates effects of neglect on bodyweight across the life span and how emotional neglect and bodyweight are linked via mental distress. Within a large survey representative of the German population (N = 2,500), individuals completed measures of mental distress, childhood trauma, and height and weight. We conducted logistic regression analyses on bodyweight extremes and a moderated mediation analysis. In men, physical neglect aggravated the risk to be underweight. In women, emotional neglect was linked to severe obesity. In both sexes, emotional neglect was related to mental distress. We found an indirect effect of emotional neglect on bodyweight via mental distress, however, it was only present in women. Our results attest to long-term consequences of adverse early experiences. We showed a possible mechanism for women’s higher vulnerability towards eating disorders. In general, investigations of eating and weight disorders should also include men and employ sex-specific methods of analyses. Lastly, neglect should also receive more attention to prevent suffering and negative sequelae over the life span.

Impaired inhibition as an intermediate phenotype for PTSD risk and treatment response

Inhibition of fear involves learning and then appropriately responding to safety signals, and has been shown to be impaired in PTSD patients. Response inhibition refers to cognitive control and likely uses the same prefrontal cortex circuits as fear inhibition, and has also been implicated in PTSD. Impaired inhibition can serve as an intermediate phenotype for PTSD and can be measured with neuroimaging and psychophysiological tools. We first review the neurobiological mechanisms of fear and response inhibition. Next, we summarize the functional magnetic resonance imaging (fMRI) and psychophysiological studies using fear and response inhibition paradigms in PTSD patients. Finally, we evaluate the theranostic role of impaired inhibition in PTSD risk and treatment response.

Kindheitsbelastungen und gestörtes Essverhalten – Die Rolle von Selbstregulation

Zusammenfassung. Die verschiedenen Formen der Kindesmisshandlung (körperlicher, sexueller oder emotionaler Missbrauch sowie emotionale und körperliche Vernachlässigung) gelten sowohl für die Entwicklung von Essstörungen als auch für einzelne Symptome pathologischen Essverhaltens (Essanfälle, Adipositas) als Risikofaktoren. Darüber hinaus ist bekannt, dass sich selbstregulatorische Fähigkeiten durch die Erfahrung von Kindesmisshandlung defizitär entwickeln können. Aus diesem Grund soll die Rolle von Selbstregulation für den Zusammenhang von erinnerter Kindheitsbelastung und Essverhalten eruiert werden, um Ansatzpunkte für Prävention und Behandlung von gestörtem Essverhalten zu erhalten. Eine hinsichtlich Geschlecht, Alter und Bildung bevölkerungsrepräsentative Stichprobe von 2508 Personen (1174 Männer und 1334 Frauen) im Alter von 14–92 Jahren ( M = 49.67, SD = 18.32) wurde im Rahmen eines umfassenden Gesundheits-Surveys zu Essverhalten, erinnerter Kindheitsbelastung und selbstregulatorischen Fähigkeiten befragt. Neben umfangreichen deskriptiven Analysen zu Essverhalten und Kindheitsbelastung wurde die Interaktion von Selbstregulation und Kindheitsbelastung unter Berücksichtigung von Geschlechtsunterschieden auf die Ausprägungen des Essverhaltens mittels einer moderierten Regressionsanalyse überprüft. Die Prävalenzraten für auffälliges Essverhalten liegen für Frauen höher als für Männer (14.7% vs. 6.5%). Frauen berichteten ebenfalls häufiger, dass sie eine Form der Kindesmisshandlung erlebt haben. Bei Betrachtung der einzelnen Formen von Kindesmisshandlung unterscheiden sich Männer und Frauen nur in der Häufigkeit von sexuellem Missbrauch, den Frauen häufiger berichteten. Die Interaktion aus höherer Kindheitsbelastung und Selbstregulationsdefiziten stellte sich lediglich für Männer als Risikofaktor für gestörtes Essverhalten heraus, nicht bei Frauen. Männer und Frauen zeigen unterschiedliche Risikoprofile, die weiter untersucht werden sollten. Bessere Kenntnisse geschlechtsspezifischer Unterschiede dienen der Prävention und Behandlung von Essstörungen sowie Adipositas.

Improving our understanding of the relationship between emotional abuse and substance use disorders: the mediating roles of negative urgency and posttraumatic stress disorder

Background: Emotional abuse is associated with an increased risk for substance use disorders (SUDs) as well as with negative urgency and posttraumatic stress disorder (PTSD) following a subsequent trauma. Both negative urgency and PTSD are key contributors to the relationship between emotional abuse and SUDs when examined separately. A comprehensive model including both factors can inform models of PTSD-SUD comorbidity. Furthermore, the comparison of these mechanistic roles in emotional versus other types of abuse can shed light on the specificity of these effects. Objectives: The present study tested whether negative urgency and PTSD symptom severity serially mediated the relationship between emotional abuse and substance use across two separate samples. Method: Participants were recruited from a detoxification center and completed a battery of surveys examining abuse history, PTSD symptom severity, and impulsivity measures including negative urgency and substance use history during the last 3 months. The samples consisted of predominantly (59% and 62%) males with an average age of 35 (age range: 18-65). The majority of participants (90% and 93%) were Caucasian. Results: Study 1 (N = 368) and Study 2 (N = 274) both found that negative urgency and PTSD symptom severity serially mediated the relationship between emotional abuse and substance use. When comparing indirect effects, both contributed equally. Conclusion: These findings suggest that negative urgency and PTSD symptom severity together account more for the link between emotional abuse and SUDs than either alone and argue for the inclusion of negative urgency in models of PTSD-SUD comorbidity.

Impact of Oxytocin on the neural correlates of fearful face processing in PTSD related to childhood Trauma

Background: Posttraumatic stress disorder (PTSD) related to exposure to abuse and neglect during childhood is associated with particularly severe and persistent deleterious outcomes. Amygdala hyperreactivity has been observed in childhood trauma survivors and implicated in symptoms of PTSD. Objective: The neuropeptide oxytocin holds promise as a potential treatment for PTSD due to its ability to attenuate amygdala response to threat cues. However, the effect of oxytocin on amygdala reactivity in individuals with childhood trauma-related PTSD has not been investigated. Method: We employed a double-blind, randomized, placebo-controlled crossover design to examine the effects of intranasal oxytocin (24 IU) versus placebo on amygdala reactivity to fearful faces among childhood-trauma exposed individuals with PTSD (n = 17) and without PTSD (control group; n = 16). Results: Region-of-interest based amygdala fMRI signal magnitude did not differ by group, drug, or group x drug interaction. Self-report of childhood trauma exposure severity was negatively associated with the oxytocin-related change in left amygdala response in the PTSD group, but not in the control group. Supplementary and exploratory whole-brain analyses conducted separately in each group revealed that left amygdala reactivity to fearful faces was absent on placebo but increased on oxytocin in the control group. The PTSD group showed right amygdala activation to fearful faces in both the oxytocin and placebo conditions, but the left amygdala response observed in the placebo condition was diminished on oxytocin. Conclusions: Findings extend the literature pertaining to the potential for oxytocin to attenuate neural correlates of PTSD to a childhood trauma-related PTSD sample.

Cortical surface area reduction in identification of subjects at high risk for post-traumatic stress disorder: A pilot study

OBJECTIVE

Victims of motor vehicle accidents often develop post-traumatic stress disorder, which causes significant social function loss. For the difficulty in treating post-traumatic stress disorder, identification of subjects at high risk for post-traumatic stress disorder is essential for providing possible intervention. This paper aims to examine the cortical structural traits related to susceptibility to post-traumatic stress disorder.

METHODS

To address this issue, we performed structural magnetic resonance imaging study in motor vehicle accident victims within 48 hours from the accidents. A total of 70 victims, available for both clinical and magnetic resonance imaging data, enrolled in our study. Upon completion of 6-month follow-up, 29 of them developed post-traumatic stress disorder, while 41 of them didn't. At baseline, voxelwise comparisons of cortical thickness, cortical area and cortical volume were conducted between post-traumatic stress disorder group and trauma control group.

RESULTS

As expected, several reduced cortical volume within frontal-temporal loop were observed in post-traumatic stress disorder. For cortical thickness, no between-group differences were observed. There were three clusters in left hemisphere and one cluster in right hemisphere showing decreased cortical area in post-traumatic stress disorder patients, compared with trauma controls. Peak voxels of the three clusters in left hemisphere were separately located in superior parietal cortex, insula and rostral anterior cingulate cortex.

CONCLUSION

The finding of reduced surface area of left insula and left rostral anterior cingulate cortex suggests that shrinked surface area in motor vehicle accident victims could act as potential biomarker of subjects at high risk for post-traumatic stress disorder.

Childhood trauma moderates inhibitory control and anterior cingulate cortex activation during stress

OBJECTIVE

The anterior cingulate cortex (ACC) is critical for both stress and inhibitory control processes and has been implicated in childhood trauma. This prospective study tested the hypothesis that early trauma moderates the association between inhibitory control during late childhood and ACC stress reactivity during adolescence.

METHOD

Sixty-four adolescents were stratified into higher- or lower-childhood-trauma groups. Inhibitory control was indicated by fewer errors on a Stroop Color-Word task. Personalized stress cues during functional magnetic resonance imaging assessed neural correlates of stress in adolescents.

RESULTS

Using a priori-defined anterior (rCZa) and posterior rostral cingulate zones of the ACC, associated with Stroop Color-Word task performance in prior meta-analyses, Stroop errors correlated inversely with activation in the rCZa during stress-cue exposure (r = -.23, p = .04). Childhood trauma moderated the association between Stroop errors and rCZa stress reactivity (interaction = -1.26, p = .02, 95%CI = -2.33,-0.20), where Stroop errors were inversely associated with brain activation among those with higher childhood trauma (simple slopes = -.83, p = .007, 95%CI = -1.40,-0.25). Low stress-related rCZa activation inversely (R² = 0.19, b = -0.43, p = .001, 95%CI = -4.11,-1.06) and Stroop errors directly (R² = 0.09, b = 0.27, p = .048, 95%CI = 0.02, 5.8) associated with baseline subjective anxiety while controlling for childhood trauma.

CONCLUSIONS

This is the first study to demonstrate a moderating role of childhood trauma on the relationship between inhibitory control and stress-related ACC activation. Childhood trauma may portend neurodevelopmental changes that impede recruitment of control-associated ACC-functioning during distress, which may relate to dysregulation of stress-induced affective responses. Further work is needed to elucidate relationships between childhood trauma and addictive behaviors precipitated by stress.

Increased cognitive control and reduced emotional interference is associated with reduced PTSD symptom severity in a trauma-exposed sample: A preliminary longitudinal study

Individuals with posttraumatic stress disorder (PTSD) show deficits in recruiting neural regions associated with cognitive control. In contrast, trauma exposed individuals (TEIs) show increased recruitment of these regions. While many individuals who experience a trauma exhibit some PTSD symptoms, relatively few develop PTSD. Despite this, no work has examined the relationship between changes in PTSD symptoms and changes in neural functioning in TEIs longitudinally. This study examined the neural correlates of changing PTSD symptom levels in TEIs. Twenty-one military service members completed the affective stroop task while undergoing fMRI within 2 months of returning from deployment and a second scan 6-12 months later. Participants with PTSD or depression at baseline were excluded. PTSD symptom improvement was associated with greater increase in response to incongruent relative to congruent negative stimuli in dorsal anterior cingulate cortex and inferior frontal gyrus/anterior insula and increased BOLD response over time to emotional relative to neutral stimuli in inferior parietal cortex. Improvement in PTSD symptoms were not associated with changes in amygdala responsiveness to emotional stimuli. In short, the current data indicate that TEIs who become more able to recruit regions implicated in cognitive control show greater reductions in PTSD symptom levels.

The Role of the Hippocampus in Predicting Future Posttraumatic Stress Disorder Symptoms in Recently Traumatized Civilians

BACKGROUND

Understanding the neurobiological mechanisms that predict posttraumatic stress disorder (PTSD) in recent trauma survivors is important for early interventions. Impaired inhibition of fear or behavioral responses is thought to be central to PTSD symptomatology, but its role in predicting PTSD is unknown. Here we examine whether brain function during response inhibition early after a civilian trauma can predict future PTSD symptoms.

METHODS

Participants (original sample, n = 27; replication sample, n = 31) were recruited in the emergency department within 24 hours of trauma exposure. PTSD symptoms were assessed in the emergency department and 1, 3, and 6 months posttrauma. A Go/NoGo procedure in a 3T magnetic resonance imaging scanner was used to measure neural correlates of response inhibition 1 to 2 months posttrauma. Elastic net regression was used to define the most optimal model to predict PTSD symptoms at 3 and 6 months among demographic, clinical, and imaging measures.

RESULTS

Less hippocampal activation was a significant predictor in the model predicting PTSD symptoms at 3 months (F_11,22 = 4.33, p = .01) and 6 months (F_9,19 = 4.96, p = .01). Other significant predictors in the model were race and pain level in the emergency department (3 months), and race and baseline depression symptoms (6 months). Using these predictors in a linear regression in the replication sample again resulted in significant models (3 months [F_3,23 = 3.03, p = .05], 6 months [F_3,20 = 5.74, p = .007]) with hippocampal activation predicting PTSD symptoms at 3 and 6 months.

CONCLUSIONS

Decreased inhibition-related hippocampal activation soon after trauma predicted future PTSD symptom severity. This finding may contribute to early identification of at-risk individuals and reveals potential targets for intervention or symptom prevention in the aftermath of trauma.

Early life stress, FK506 binding protein 5 gene (FKBP5) methylation, and inhibition-related prefrontal function: A prospective longitudinal study

Individuals who have experienced high levels of childhood stress are at increased risk for a wide range of behavioral problems that persist into adulthood, yet the neurobiological and molecular mechanisms underlying these associations remain poorly understood. Many of the difficulties observed in stress-exposed children involve problems with learning and inhibitory control. This experiment was designed to test individuals' ability to learn to inhibit responding during a laboratory task. To do so, we measured stress exposure among a community sample of school-aged children, and then followed these children for a decade. Those from the highest and lowest quintiles of childhood stress exposure were invited to return to our laboratory as young adults. At that time, we reassessed their life stress exposure, acquired functional magnetic resonance imaging data during an inhibitory control task, and assayed these individuals' levels of methylation in the FK506 binding protein 5 (FKBP5) gene. We found that individuals who experienced high levels of stress in childhood showed less differentiation in the dorsolateral prefrontal cortex between error and correct trials during inhibition. This effect was associated only with childhood stress exposure and not by current levels of stress in adulthood. In addition, FKBP5 methylation mediated the association between early life stress and inhibition-related prefrontal activity. These findings are discussed in terms of using multiple levels of analyses to understand the ways in which adversity in early development may affect adult behavioral adaptation.

COMT val158met polymorphism links to altered fear conditioning and extinction are modulated by PTSD and childhood trauma

BACKGROUND

Risk for posttraumatic stress disorder (PTSD) is thought to be mediated by gene × environment (G × E) interactions that affect core cognitive processes such as fear learning. The catechol-O-methyltransferase (COMT) val158met polymorphism has been associated with risk for PTSD and impaired fear inhibition. We used a large, relatively homogenous population to (1) replicate previous findings of poor fear inhibition in COMT Met/Met carriers with PTSD; (2) determine if COMT association with fear inhibition is moderated by childhood trauma (CT), an environmental risk factor for PTSD; and (3) determine if COMT is associated with altered fear processes after recent exposure to combat trauma.

METHODS

Male Marines and Navy Corpsmen of European-American ancestry were assessed prior to (n = 714) and 4-6 months after deployment to Afghanistan (n = 452). Acquisition and extinction of fear-potentiated startle, childhood and combat trauma history, and PTSD diagnosis were assessed at both time points.

RESULTS

Before deployment, Met/Met genotype was associated with fear inhibition deficits in participants with current PTSD; however, this association was dependent on CT exposure. After deployment, combat trauma was associated with a modest reduction in fear extinction in Met/Met compared with Val/Val carriers. There were no associations of COMT genotype with fear extinction within healthy and non-traumatized individuals.

CONCLUSIONS

These findings support the hypothesis that G × E interactions underlie associations of COMT val158met with fear inhibition deficits. These studies confirm that Met/Met carriers with PTSD have poor fear inhibition, and support further research in understanding how this polymorphism might impact response to extinction-based therapies.

Neuroimaging Correlates of Resilience to Traumatic Events-A Comprehensive Review

Improved understanding of the neurobiological correlates of resilience would be an important step toward recognizing individuals at risk of developing post-traumatic stress disorder (PTSD) or other trauma-related diseases, enabling both preventative measures and individually tailored therapeutic approaches. Studies on vulnerability factors allow drawing conclusions on resilience. Structural changes of cortical and subcortical structures, as well as alterations in functional connectivity and functional activity, have been demonstrated to occur in individuals with PTSD symptoms. Relevant areas of interest are hippocampus, amygdala, insula, anterior cingulate cortex, and prefrontal cortex, as well as related brain networks, such as the default-mode, salience, and central executive network. This review summarizes the existing literature and integrates findings from cross-sectional study designs with two-group designs (trauma exposed individuals with and without PTSD), three-group designs (with an additional group of unexposed, healthy controls), twin-studies and longitudinal studies. In terms of structural findings, decreased hippocampal volume in PTSD individuals might be either a vulnerability factor or a result of trauma exposure, or both. Reduced anterior cingulate cortex and prefrontal cortex volumes seem to be predisposing factors for increased vulnerability. Regarding functional connectivity, increased amygdala connectivity has been demonstrated selectively in PTSD individuals, as well as increased default-mode-network and salience network connectivity. In terms of functional activity, increased amygdala and anterior cingulate cortex activities, and decreased prefrontal cortex activity as a response to external stimuli have been associated with higher vulnerability. Increased prefrontal cortex activity seemed to be a protective factor. Selecting adequate study designs, optimizing the diagnostic criteria, as well as differentiating between types of trauma and accounting for other factors, such as gender-specific differences, would be well-served in future research. Conclusions on potential preventative measures, as well as clinical applications, can be drawn from the present literature, but more studies are needed.

Childhood Trauma and COMT Genotype Interact to Increase Hippocampal Activation in Resilient Individuals

Both childhood trauma and a functional catechol-O-methyltransferase (COMT) genetic polymorphism have been associated with posttraumatic stress disorder (PTSD) and depression; however, it is still unclear whether the two interact and how this interaction relates to long-term risk or resilience. Imaging and genotype data were collected on 73 highly traumatized women. DNA extracted from saliva was used to determine COMT genotype (Val/Val, n = 38, Met carriers, n = 35). Functional MRI data were collected during a Go/NoGo task to investigate the neurocircuitry underlying response inhibition. Self-report measures of adult and childhood trauma exposure, PTSD and depression symptom severity, and resilience were collected. Childhood trauma was found to interact with COMT genotype to impact inhibition-related hippocampal activation. In Met carriers, more childhood trauma was associated with decreased hippocampal activation, whereas in the Val/Val group childhood trauma was related to increased hippocampal activation. Second, hippocampal activation correlated negatively with PTSD and depression symptoms and positively with trait resilience. Moreover, hippocampal activation mediated the relationship between childhood trauma and psychiatric risk or resilience in the Val/Val, but not in the Met carrier group. These data reveal a potential mechanism by which childhood trauma and COMT genotype interact to increase risk for trauma-related psychopathology or resilience. Hippocampal recruitment during inhibition may improve the ability to use contextual information to guide behavior, thereby enhancing resilience in trauma-exposed individuals. This finding may contribute to early identification of individuals at risk and suggests a mechanism that can be targeted in future studies aiming to prevent or limit negative outcomes.