Early life stress predicts thalamic hyperconnectivity: A transdiagnostic study of global connectivity

Early Life Stress and Major Depressive Disorder-An Update on Molecular Mechanisms and Synaptic Impairments

Early life stress (ELS), characterized as abuse, neglect, and abandonment, can cause several adverse consequences in the lives of affected individuals. ELS experiences can affect an individual's development in variable ways, persisting in the long term and promoting lasting impacts, considering that early exposure to stressors can be biologically incorporated, as prolonged stimulation of stress response systems affects the development of the brain structure and other body systems, increasing the risk of diseases associated with stress and cognitive impairment. This type of stress increases the risk of developing major depressive disorder (MDD) in a severe form that does not respond adequately to traditional antidepressant treatments. Several alterations are studied as mechanisms that relate ELS with MDD, such as epigenetic alterations, neurotransmitters, and neuronal signaling. This review discusses research that brings evidence about the ELS mechanisms involved in synaptic impairments and MDD. The processes involved in epigenetic changes and the HPA axis are highlighted, as well as changes in neurotransmitters and neuronal signaling mechanisms.

Restoring the Function of Thalamocortical Circuit Through Correcting Thalamic Kv3.2 Channelopathy Normalizes Fear Extinction Impairments in a PTSD Mouse Model

Impaired extinction of fear memory is one of the most common symptoms in post-traumatic stress disorder (PTSD), with limited therapeutic strategies due to the poor understanding of its underlying neural substrates. In this study, functional screening is performed and identified hyperactivity in the mediodorsal thalamic nucleus (MD) during fear extinction. Furthermore, the encoding patterns of the hyperactivated MD is investigated during persistent fear responses using multiple machine learning algorithms. The anterior cingulate cortex (ACC) is also identified as a functional downstream region of the MD that mediates the extinction of fear memory. The thalamocortical circuit is comprehensively analyzed and found that the MD-ACC parvalbumin interneurons circuit is preferentially enhanced in PTSD mice, disrupting the local excitatory and inhibitory balance. It is found that decreased phosphorylation of the Kv3.2 channel contributed to the hyperactivated MD, primarily to the malfunctioning thalamocortical circuit. Using a lipid nanoparticle-based RNA therapy strategy, channelopathy is corrected via a methoxylated siRNA targeting the protein phosphatase 6 catalytic subunit and restored fear memory extinction in PTSD mice. These findings highlight the function of the thalamocortical circuit in PTSD-related impaired extinction of fear memory and provide therapeutic insights into Kv3.2-targeted RNA therapy for PTSD.

Abnormal dynamic functional connectivity of thalamic subregions in patients with first-episode, drug-naïve major depressive disorder

Background

Recent studies have shown that major depressive disorder (MDD) is associated with altered intrinsic functional connectivity (FC) of the thalamus; however, investigations of these alterations at a finer time scale and the level of thalamic subregions are still lacking.

Methods

We collected resting-state functional MRI data from 100 treatment-naïve, first-episode MDD patients and 99 age-, gender- and education-matched healthy controls (HCs). Seed-based whole-brain sliding window-based dFC analyses were performed for 16 thalamic subregions. Between-group differences in the mean and variance of dFC were determined using threshold-free cluster enhancement algorithm. For significant alterations, there relationships with clinical and neuropsychological variables were further examined via bivariate and multivariate correlation analyses.

Results

Of all thalamic subregions, only the left sensory thalamus (Stha) showed altered variance of dFC in the patients characterized by increases with the left inferior parietal lobule, left superior frontal gyrus, left inferior temporal gyrus, and left precuneus, and decreases with multiple frontal, temporal, parietal, and subcortical regions. These alterations accounted for, to a great extent, clinical, and neuropsychological characteristics of the patients as revealed by the multivariate correlation analysis. In addition, the bivariate correlation analysis revealed a positive correlation between the variance of dFC between the left Stha and right inferior temporal gurus/fusiform and childhood trauma questionnaires scores (r = 0.562, P < 0.001).

Conclusion

These findings suggest that the left Stha is the most vulnerable thalamic subregion to MDD, whose dFC alterations may serve as potential biomarkers for the diagnosis of the disease.

Structural brain correlates of childhood trauma with replication across two large, independent community-based samples

INTRODUCTION

Childhood trauma and adversity are common across societies and have strong associations with physical and psychiatric morbidity throughout the life-course. One possible mechanism through which childhood trauma may predispose individuals to poor psychiatric outcomes is via associations with brain structure. This study aimed to elucidate the associations between childhood trauma and brain structure across two large, independent community cohorts.

METHODS

The two samples comprised (i) a subsample of Generation Scotland (n=1,024); and (ii) individuals from UK Biobank (n=27,202). This comprised n=28,226 for mega-analysis. MRI scans were processed using Free Surfer, providing cortical, subcortical, and global brain metrics. Regression models were used to determine associations between childhood trauma measures and brain metrics and psychiatric phenotypes.

RESULTS

Childhood trauma associated with lifetime depression across cohorts (OR 1.06 GS, 1.23 UKB), and related to early onset and recurrent course within both samples. There was evidence for associations between childhood trauma and structural brain metrics. This included reduced global brain volume, and reduced cortical surface area with highest effects in the frontal (β=-0.0385, SE=0.0048, p(FDR)=5.43x10-15) and parietal lobes (β=-0.0387, SE=0.005, p(FDR)=1.56x10-14). At a regional level the ventral diencephalon (VDc) displayed significant associations with childhood trauma measures across both cohorts and at mega-analysis (β=-0.0232, SE=0.0039, p(FDR)=2.91x10-8). There were also associations with reduced hippocampus, thalamus, and nucleus accumbens volumes.

DISCUSSION

Associations between childhood trauma and reduced global and regional brain volumes were found, across two independent UK cohorts, and at mega-analysis. This provides robust evidence for a lasting effect of childhood adversity on brain structure.

Maternal psychological distress associates with alterations in resting-state low-frequency fluctuations and distal functional connectivity of the neonate medial prefrontal cortex

Prenatal stress exposure (PSE) has been observed to exert a programming effect on the developing infant brain, possibly with long-lasting consequences on temperament, cognitive functions and the risk for developing psychiatric disorders. Several prior studies have revealed that PSE associates with alterations in neonate functional connectivity in the prefrontal regions and amygdala. In this study, we explored whether maternal psychological symptoms measured during the 24th gestational week had associations with neonate resting-state network metrics. Twenty-one neonates (nine female) underwent resting-state fMRI scanning (mean gestation-corrected age at scan 26.95 days) to assess fractional amplitude of low-frequency fluctuation (fALFF) and regional homogeneity (ReHo). The ReHo/fALFF maps were used in multiple regression analysis to investigate whether maternal self-reported anxiety and/or depressive symptoms associate with neonate functional brain features. Maternal psychological distress (composite score of depressive and anxiety symptoms) was positively associated with fALFF in the neonate medial prefrontal cortex (mPFC). Anxiety and depressive symptoms, assessed separately, exhibited similar but weaker associations. Post hoc seed-based connectivity analyses further showed that distal connectivity of mPFC covaried with PSE. No associations were found between neonate ReHo and PSE. These results offer preliminary evidence that PSE may affect functional features of the developing brain during gestation.

FKBP5 intron 7 methylation is associated with higher anxiety proneness and smaller right thalamus volume in adolescents

Dysregulation of stress response systems may mediate the detrimental effects of childhood trauma (CT) on mental health. FKBP5 regulates glucocorticoid receptor sensitivity and exerts pleiotropic effects on intracellular signaling, neurobiology and behavior. We investigated whether CT, alone and in combination with rs1360780 genotype, is associated with altered FKBP5 methylation and whether CT-associated methylation profiles are associated with anxiety proneness (AP) and structural brain volumes. Ninety-four adolescents completed the Childhood Trauma Questionnaire, and a composite AP score was generated from the Childhood Anxiety Sensitivity Index and the State-Trait Anxiety Inventory-Trait measure. Mean methylation values for 12 regulatory regions and 25 individual CpG sites were determined using high-accuracy measurement via targeted bisulfite sequencing. FKBP5 rs1360780 genotype and structural MRI data were available for a subset of participants (n = 71 and n = 75, respectively). Regression models revealed an inverse association between methylation of three intron 7 CpG sites (35558438, 35558566 and 35558710) and right thalamus volume. CpG35558438 methylation was positively associated with AP scores. Our data indicate that an intron 7 methylation profile, consistent with lower FKBP5 expression and elevated high sensitivity glucocorticoid receptor levels, is associated with higher AP and smaller right thalamus volume. Research into the mechanisms underlying the intron 7 methylation-thalamus volume relationship, and whether it confers increased risk for long-term psychopathology by altering the regulatory threshold of stress responding, is required.

The impact of childhood trauma on thalamic functional connectivity in patients with obsessive-compulsive disorder

BACKGROUND

Childhood trauma is a vulnerability factor for the development of obsessive-compulsive disorder (OCD). Empirical findings suggest that trauma-related alterations in brain networks, especially in thalamus-related regions, have been observed in OCD patients. However, the relationship between childhood trauma and thalamic connectivity in patients with OCD remains unclear. The present study aimed to examine the impact of childhood trauma on thalamic functional connectivity in OCD patients.

METHODS

Magnetic resonance imaging resting-state scans were acquired in 79 patients with OCD, including 22 patients with a high level of childhood trauma (OCD_HCT), 57 patients with a low level of childhood trauma (OCD_LCT) and 47 healthy controls. Seven thalamic subdivisions were chosen as regions of interest (ROIs) to examine the group difference in thalamic ROIs and whole-brain resting-state functional connectivity (rsFC).

RESULTS

We found significantly decreased caudate-thalamic rsFC in OCD patients as a whole group and also in OCD_LCT patients, compared with healthy controls. However, OCD_HCT patients exhibited increased thalamic rsFC with the prefrontal cortex when compared with both OCD_LCT patients and healthy controls.

CONCLUSIONS

Taken together, OCD patients with high and low levels of childhood trauma exhibit different pathological alterations in thalamic rsFC, suggesting that childhood trauma may be a predisposing factor for some OCD patients.

Neural processes during response inhibition in complex posttraumatic stress disorder

BACKGROUND

A common feature of complex posttraumatic stress disorder (CPTSD) is impulsivity. Despite the importance of this characteristic in functional difficulties in CPTSD, little is known about its mechanisms. The aim of this study was to identify the distinctive neural profile of CPTSD during attempted inhibition.

METHODS

The present study examined functional alterations in neural networks involved in inhibitory control across functional magnetic resonance imaging (fMRI) and electroencephalogram (EEG) paradigms in CPTSD (n = 30), PTSD (n = 40), and healthy control (n = 40) participants who completed a Go/NoGo response inhibition task during separate fMRI and EEG sessions. Brain activations were calculated during the NoGo trials relative to the baseline to evaluate response inhibition functioning.

RESULTS

There was reduced bilateral thalamic activation in participants with CPTSD relative to PTSD and controls during inhibition trials, but no activation differences between PTSD and controls for this brain region. There were no differences in functional connectivity between the thalamus and other regions involved in cognitive control between groups. No differences were observed between groups on EEG responses.

CONCLUSIONS

These findings provide initial evidence of aberrant functioning in the neurocircuitry of inhibitory control, involving the thalamus, in CPTSD. This evidence suggests that CPTSD is distinguished from PTSD by impaired neural processes implicated in response inhibition.

The Role of the Thalamus in Post-Traumatic Stress Disorder

Post-traumatic stress disorder (PTSD) has a high lifetime prevalence and is one of the more serious challenges in mental health care. Fear-conditioned learning involving the amygdala has been thought to be one of the main causative factors; however, recent studies have reported abnormalities in the thalamus of PTSD patients, which may explain the mechanism of interventions such as eye movement desensitization and reprocessing (EMDR). Therefore, I conducted a miniature literature review on the potential contribution of the thalamus to the pathogenesis of PTSD and the validation of therapeutic approaches. As a result, we noticed the importance of the retinotectal pathway (superior colliculus−pulvinar−amygdala connection) and discussed therapeutic indicators.

Unraveling the Consequences of Childhood Maltreatment: Deviations From Typical Functional Neurodevelopment Mediate the Relationship Between Maltreatment History and Depressive Symptoms

BACKGROUND

Childhood maltreatment is associated with lifelong psychiatric sequelae. However, our understanding of neurobiological mechanisms responsible for this association is limited. Childhood maltreatment may confer risk for psychopathology by altering neurodevelopmental trajectories during childhood and adolescence. Longitudinal research, which is essential for examining this question, has been limited.

METHODS

We investigated maltreatment-associated alterations in the development of neural circuitry. Associations between cumulative childhood maltreatment (assessed using a dimensional measure of abuse and neglect via the Childhood Trauma Questionnaire) and the longitudinal development of resting-state functional connectivity (rsFC) were examined in 130 community-residing adolescents. Functional magnetic resonance imaging data were acquired at age 16 (T1; mean ± SD age, 16.46 ± 0.52 years; 66 females) and age 19 (T2; mean follow-up period, 2.35 years; n = 90 with functional magnetic resonance imaging data at both time points).

RESULTS

We found maltreatment to be associated with widespread longitudinal increases in rsFC, primarily between default mode, dorsal attention, and frontoparietal systems. We also found sex-dependent increased maltreatment-associated rsFC in male participants in salience and limbic circuits. Cross-sectional analyses revealed a shift in maltreatment-related rsFC alterations, which were localized to subcortical and sensory circuits at T1 and to frontal circuits at T2. Finally, longitudinal increases in rsFC connectivity mediated the relationship between childhood maltreatment and increased depressive symptoms.

CONCLUSIONS

To our knowledge, this is the first study to examine longitudinal maltreatment-related alterations in rsFC in adolescents. Our findings shed light on the neurodevelopmental consequences of childhood maltreatment and provide evidence for their role in risk for depression.

Abnormal asymmetry of thalamic volume moderates stress from parents and anxiety symptoms in children and adolescents with social anxiety disorder

Social anxiety disorder (SAD) usually onsets in childhood or adolescence and is associated with brain development and chronic family stress during this period. As an information hub, the thalamus plays a crucial role in the development of emotion processing and stress regulation. Its structural and functional lateralization have been related to mental disorders. This study examined the age-dependent asymmetry of the thalamic volume in children and adolescents with SAD. We further examined the role of the thalamic asymmetry in moderating the relationships between parental alienation, which is a main source of familial stress for children and adolescents, and anxiety symptoms in this population. Fifty-three medication-free children and adolescents with SAD and 53 typical developing controls (age: 8-17) were included. Anxiety severity was measured using the Screen for Child Anxiety-Related Emotional Disorders (SCARED). We estimated the bilateral thalamic volume and examined diagnosis effect and age-group difference on the thalamic asymmetry. We further examined the moderation of the thalamic asymmetry on the associations between scores on the parental alienation, social phobia, and total SCARED. Compared with controls, the SAD group exhibited significantly abnormal asymmetry in thalamic volume. This asymmetry became more evident in the older age group. Furthermore, this asymmetry significantly weakened the relationships between parental attachment and total SCARED score. The asymmetry of the thalamic volume and its age-group difference provide novel evidence to support brain developmental abnormalities in children and adolescents with SAD. The findings further revealed interactions between physiological and chronic stress in children and adolescents with SAD. This article is part of the special issue on 'Stress, Addiction and Plasticity'.

Resting State Functional Connectivity of the Thalamus in North Korean Refugees with and without Posttraumatic Stress Disorder

In posttraumatic stress disorder (PTSD), functional connectivity (FC) between the thalamus and other brain areas has yet to be comprehensively investigated. The present study explored resting state FC (rsFC) of thalamus and its associations with trauma-related features. The included subjects were North Korean refugees with PTSD (n = 23), trauma-exposed North Korean refugees without PTSD (trauma-exposed control [TEC] group, n = 22), and South Korean healthy controls (HCs) without traumatic experiences (HC group, n = 40). All participants underwent psychiatric evaluation and functional magnetic resonance imaging (fMRI) procedures using the bilateral thalamus as seeds. In the TEC group, the negative rsFC between each thalamus and its contralateral postcentral cortex was stronger relative to the PTSD and HC groups, while positive rsFC between the left thalamus and left precentral cortex was stronger in the HC group compared to the PTSD and TEC groups. Thalamo-postcentral rsFC was positively correlated with the CAPS total score in the TEC group, and with the number of traumatic experiences in the PTSD group. The present study identified the difference of thalamic rsFC alterations among traumatized refugees and HCs. Negative rsFC between the thalamus and somatosensory cortices might be compensatory changes after multiple traumatic events in refugees.

The Resilient Emotional Brain: A Scoping Review of the Medial Prefrontal Cortex and Limbic Structure and Function in Resilient Adults With a History of Childhood Maltreatment

Childhood maltreatment (CM) is one of the strongest predictors of adult mental illness, although not all adults with CM develop psychopathology. Here, we describe the structure and function of the emotional brain regions that may contribute to resilient functioning after CM. We review studies that report medial prefrontal cortex, amygdala, and hippocampus (limbic regions) structure, function, and/or connections in resilient adults (i.e., those reporting CM without psychopathology) versus vulnerable adults (i.e., those reporting CM with psychopathology) or healthy adults (those without CM and with no psychopathology). We find that resilient adults have larger hippocampal gray and white matter volume and greater connectivity between the central executive network and the limbic regions. In addition, resilient adults have improved ability to regulate emotions through medial prefrontal cortex-limbic downregulation, lower hippocampal activation to emotional faces, and increased amygdala habituation to stress. We highlight the need for longitudinal designs that examine resilient functioning across domains and consider gender, type, timing, and nature of CM assessments and further stressors to further improve our understanding of the role of the emotional brain in resilient functioning after CM.

Review of childhood pain highlights the role of negative stress

AIM

Recurrent pain of unknown origin is a major problem in children. The aim of the present review was to examine the hypothesis of negative stress as an aetiology of recurrent pain from different aspects.

METHODS AND RESULTS

Epidemiological studies, clinical experience and hormonal data give support for such a hypothesis. Negative stress as a tentative aetiology for recurrent pain is reviewed. Stress, muscular tension, the startle reaction and its tentative relation to pain is illuminated. Deviations of hormonal secretion supporting a stress aetiology are mentioned. The role of central sensitisation for recurrent pain is discussed. Possible aetiological implications of recurrent pain as a local symptom or a general disorder are presented. Brain changes due to stress are shortly reviewed. Stress and pain in the clinic are highlighted. The importance of biological, psychological and social factors, as well as genetic elements, is discussed.

CONCLUSION

Stress elicits neurobiological mechanisms. They may lead to many neurophysiological deviances. Increase of muscle tension and neuromuscular excitability and enhanced startle reaction may be of importance for recurring pain. The identification of stress as a primary cause of recurrent pain can have huge implications for understanding signs and treatment in clinical practice.

Transdiagnostic psychiatry: a systematic review

The usefulness of current psychiatric classification, which is based on ICD/DSM categorical diagnoses, remains questionable. A promising alternative has been put forward as the "transdiagnostic" approach. This is expected to cut across existing categorical diagnoses and go beyond them, to improve the way we classify and treat mental disorders. This systematic review explores whether self-defining transdiagnostic research meets such high expectations. A multi-step Web of Science literature search was performed according to an a priori protocol, to identify all studies that used the word "transdiagnostic" in their title, up to May 5, 2018. Empirical variables which indexed core characteristics were extracted, complemented by a bibliometric and conceptual analysis. A total of 111 studies were included. Most studies were investigating interventions, followed by cognition and psychological processes, and neuroscientific topics. Their samples ranged from 15 to 91,199 (median 148) participants, with a mean age from 10 to more than 60 (median 33) years. There were several methodological inconsistencies relating to the definition of the gold standard (DSM/ICD diagnoses), of the outcome measures and of the transdiagnostic approach. The quality of the studies was generally low and only a few findings were externally replicated. The majority of studies tested transdiagnostic features cutting across different diagnoses, and only a few tested new classification systems beyond the existing diagnoses. About one fifth of the studies were not transdiagnostic at all, because they investigated symptoms and not disorders, a single disorder, or because there was no diagnostic information. The bibliometric analysis revealed that transdiagnostic research largely restricted its focus to anxiety and depressive disorders. The conceptual analysis showed that transdiagnostic research is grounded more on rediscoveries than on true innovations, and that it is affected by some conceptual biases. To date, transdiagnostic approaches have not delivered a credible paradigm shift that can impact classification and clinical care. Practical "TRANSD"iagnostic recommendations are proposed here to guide future research in this field.

Cognitive control and network disruption in remitted depression: a correlate of childhood adversity

Individuals in a major depressive episode often display impairment in cognitive control, and this impairment exists outside of the acute phase of illness. Impairment in cognitive control also has been associated with exposure to childhood adversity (CA). The current study examined whether exposure to CA can explain variance in a component of cognitive control—inhibitory control—independent of diagnostic status in young adults with and without a history of depression. Healthy control individuals (n = 40) and individuals with remitted major depressive disorder (n = 53) completed a task measuring inhibitory control, reported level of CA and completed a scanning session to assess gray matter volume and resting state connectivity in regions associated with cognitive control. The results demonstrate that higher levels of CA were associated with poorer inhibitory control, reduced right middle frontal gyrus gray matter, decreased connectivity of salience and emotion networks and increased connectivity in cognitive control networks, even after controlling for diagnostic status, residual depression symptoms and current stressors. Together, the results suggest that inhibitory control impairment and intrinsic connectivity changes may be characterized as developmental sequelae of early stress exposure.

Neurocognitive Precursors of Substance Misuse Corresponding to Risk, Resistance, and Resilience Pathways: Implications for Prevention Science

Studies of substance misuse prevention generally focus on characteristics that typify risk, with the assumption that the prevalence of the problem will be optimally reduced by identifying, targeting, and reducing or eliminating risk factors. However, this risk-centered approach neglects variations in individual-level and environmental characteristics that portend differential pathways that are distinguishable by timing of substance use initiation (e.g., early versus delayed), the likelihood of use escalation versus eventual desistance, and enduring abstinence, despite exposure to significant risk factors. Considering the various underpinnings of these distinct substance use trajectories is critical to a more nuanced understanding of the effects, potency, and malleability of factors that are known to increase risk or confer protection. Here, we discuss three pathways relative to substance use patterns and predictors in the context of adversity, a well-known, highly significant influence on propensity for substance misuse. The first pathway is designated as "high risk" based on early onset of substance use, rapid escalation, and proneness to substance use disorders. Individuals who defy all odds and eventually exhibit adaptive developmental outcomes despite an initial maladaptive reaction to adversity, are referred to as "resilient." However, another categorization that has not been adequately characterized is "resistant." Resistant individuals include those who do not exhibit problematic substance use behaviors (e.g., early onset and escalation) and do not develop substance use disorders or other forms of psychopathology, despite significant exposure to factors that normally increase the propensity for such outcomes (e.g. trauma and/or adversity). In this paper, we apply this conceptualization of risk, resistance, and resilience for substance misuse to a more fine-grained analysis of substance use pathways and their corresponding patterns (e.g., non-use, initiation, escalation, desistance). The significance of the progression of neurocognitive functioning over the course of development is discussed as well as how this knowledge may be translated to make a science-based determination of intervention targets. This more encompassing theoretical model has direct implications for primary prevention and clinical approaches to disrupt risk pathways and to optimize long-term outcomes.

Impact of juvenile chronic stress on adult cortico-accumbal function: Implications for cognition and addiction

Repeated exposure to stress during childhood is associated with increased risk for neuropsychiatric illness, substance use disorders and other behavioral problems in adulthood. However, it is not clear how chronic childhood stress can lead to emergence of such a wide range of symptoms and disorders in later life. One possible explanation lies in stress-induced disruption to the development of specific brain regions associated with executive function and reward processing, deficits in which are common to the disorders promoted by childhood stress. Evidence of aberrations in prefrontal cortex and nucleus accumbens function following repeated exposure of juvenile (pre- and adolescent) organisms to a variety of different stressors would account not only for the similarity in symptoms across the wide range of childhood stress-associated mental illnesses, but also their persistence into adulthood in the absence of further stress. Therefore, the goal of this review is to evaluate the current knowledge regarding disruption to executive function and reward processing in adult animals or humans exposed to chronic stress over the juvenile period, and the underlying neurobiology, with particular emphasis on the prefrontal cortex and nucleus accumbens. First, the role of these brain regions in mediating executive function and reward processing is highlighted. Second, the neurobehavioral development of these systems is discussed to illustrate how juvenile stress may exert long-lasting effects on prefrontal cortex-accumbal activity and related behavioral functions. Finally, a critical review of current animal and human findings is presented, which strongly supports the supposition that exposure to chronic stress (particularly social aggression and isolation in animal studies) in the juvenile period produces impairments in executive function in adulthood, especially in working memory and inhibitory control. Chronic juvenile stress also results in aberrations to reward processing and seeking, with increased sensitivity to drugs of abuse particularly noted in animal models, which is in line with greater incidence of substance use disorders seen in clinical studies. These consequences are potentially mediated by monoamine and glutamatergic dysfunction in the prefrontal cortex and nucleus accumbens, providing translatable therapeutic targets. However, the predominant use of male subjects and social-based stressors in preclinical studies points to a clear need for determining how both sex differences and stressor heterogeneity may differentially contribute to stress-induced changes to substrates mediating executive function and reward processing, before the impact of chronic juvenile stress in promoting adult psychopathology can be fully understood.

Neural correlates of childhood trauma with executive function in young healthy adults

The aim of this study was to investigate the relationship among childhood trauma, executive impairments, and altered resting-state brain function in young healthy adults. Twenty four subjects with childhood trauma and 24 age- and gender-matched subjects without childhood trauma were recruited. Executive function was assessed by a series of validated test procedures. Localized brain activity was evaluated by fractional amplitude of low frequency fluctuation (fALFF) method and compared between two groups. Areas with altered fALFF were further selected as seeds in subsequent functional connectivity analysis. Correlations of fALFF and connectivity values with severity of childhood trauma and executive dysfunction were analyzed as well. Subjects with childhood trauma exhibited impaired executive function as assessed by Wisconsin Card Sorting Test and Stroop Color Word Test. Traumatic individuals also showed increased fALFF in the right precuneus and decreased fALFF in the right superior temporal gyrus. Significant correlations of specific childhood trauma severity with executive dysfunction and fALFF value in the right precuneus were found in the whole sample. In addition, individuals with childhood trauma also exhibited diminished precuneus-based connectivity in default mode network with left ventromedial prefrontal cortex, left orbitofrontal cortex, and right cerebellum. Decreased default mode network connectivity was also associated with childhood trauma severity and executive dysfunction. The present findings suggest that childhood trauma is associated with executive deficits and aberrant default mode network functions even in healthy adults. Moreover, this study demonstrates that executive dysfunction is related to disrupted default mode network connectivity.