Morphometric brain abnormalities in boys with conduct disorder

Does the Relationship between Age and Brain Structure Differ in Youth with Conduct Disorder?

Conduct disorder (CD) is characterised by persistent antisocial and aggressive behaviour and typically emerges in childhood or adolescence. Although several authors have proposed that CD is a neurodevelopmental disorder, very little evidence is available about brain development in this condition. Structural brain alterations have been observed in CD, and some indirect evidence for delayed brain maturation has been reported. However, no detailed analysis of age-related changes in brain structure in youth with CD has been conducted. Using cross-sectional MRI data, this study aimed to explore differences in brain maturation in youth with CD versus healthy controls to provide further understanding of the neurodevelopmental processes underlying CD. 291 CD cases (153 males) and 379 healthy controls (160 males) aged 9-18 years (Mage = 14.4) were selected from the European multisite FemNAT-CD study. Structural MRI scans were analysed using surface-based morphometry followed by application of the ENIGMA quality control protocols. An atlas-based approach was used to investigate group differences and test for group-by-age and group-by-age-by-sex interactions in cortical thickness, surface area and subcortical volumes. Relative to healthy controls, the CD group showed lower surface area across frontal, temporal and parietal regions as well as lower total surface area. No significant group-by-age or group-by-age-by-sex interactions were observed on any brain structure measure. These findings suggest that CD is associated with lower surface area across multiple cortical regions, but do not support the idea that CD is associated with delayed brain maturation, at least within the age bracket considered here.

Brain Anatomy in Boys with Conduct Disorder: Differences Among Aggression Subtypes

Aggression is a core feature of conduct disorder (CD), but the motivation, execution of aggression may vary. A deeper understanding of the neural substrates of aggressive behaviours is critical for effective clinical intervention. Seventy-six Boys with CD (50 with impulsive aggression (I-CD) and 26 with premeditated aggression (P-CD)) and 69 healthy controls (HCs) underwent a structural MRI scan and behavioural assessments. Whole-brain analyses revealed that, compared to HCs, the I-CD group showed significant cortical thinning in the right frontal cortex, while the P-CD group demonstrated significant folding deficits in the bilateral superior parietal cortex. Both types of aggression negatively correlated with the left amygdala volume, albeit in different ways. The present results demonstrated that the complex nature of aggression relies on differentiated anatomical substrates, highlighting the importance of exploring differential circuit-targeted interventions for CD patients.

Reduced grey matter volume in adolescents with conduct disorder: a region-of-interest analysis using multivariate generalized linear modeling

BACKGROUND

Conduct disorder (CD) involves a group of behavioral and emotional problems that usually begins during childhood or adolescence. Structural brain alterations have been observed in CD, including the amygdala, insula, ventrolateral and medial prefrontal cortex, anterior cingulate cortex, and fusiform gyrus. The current study developed a multivariate generalized linear model (GLM) to differentiate adolescents with CD from typically developing (TD) adolescents in terms of grey matter volume (GMV).

METHODS

The whole-brain structural MRI data were collected from 96 adolescents with CD (mean age = [Formula: see text] years; mean IQ = [Formula: see text]; 63 males) and 90 TD individuals (mean age = [Formula: see text] years; mean IQ = [Formula: see text]; 59 males) matched on age, IQ, and sex. Region-wise GMV was extracted following whole-brain parcellation into 68 cortical and 14 subcortical regions for each participant. A multivariate GLM was developed to predict the GMV of the pre-hypothesized regions-of-interest (ROIs) based on CD diagnosis, with intracranial volume, age, sex, and IQ serving as the covariate.

RESULTS

A diagnosis of CD was a significant predictor for GMV in the right pars orbitalis, right insula, right superior temporal gyrus, left fusiform gyrus, and left amygdala (F(1, 180) = 5.460-10.317, p < 0.05, partial eta squared = 0.029-0.054). The CD participants had smaller GMV in these regions than the TD participants (MCD-MTD = [- 614.898] mm3-[- 53.461] mm3).

CONCLUSIONS

Altered GMV within specific regions may serve as a biomarker for the development of CD in adolescents. Clinical work can potentially target these biomarkers to treat adolescents with CD.

Reduced Grey Matter Volume in Adolescents with Conduct Disorder: A Region-of-Interest Analysis Using Multivariate Generalized Linear Modeling

Background

Conduct disorder (CD) involves a group of behavioral and emotional problems that usually begins during childhood or adolescence. Structural brain alterations have been observed in CD, including the amygdala, insula, ventrolateral and medial prefrontal cortex, anterior cingulate cortex, and fusiform gyrus. The current study developed a multivariate generalized linear model (GLM) to differentiate adolescents with CD from typically developing (TD) adolescents in terms of grey matter volume (GMV).

Methods

The whole-brain structural MRI data were collected from 96 adolescents with CD (mean age = years; mean IQ = ; 63 males) and 90 TD individuals (mean age = years; mean IQ = ; 59 males) matched on age, IQ, and sex. Region-wise GMV was extracted following whole-brain parcellation into 68 cortical and 14 subcortical regions for each participant. A multivariate GLM was developed to predict the GMV of the pre-hypothesized regions-of-interest (ROIs) based on CD diagnosis, with intracranial volume, age, sex, and IQ serving as the covariate.

Results

A diagnosis of CD was a significant predictor for GMV in the right pars orbitalis, right insula, right superior temporal gyrus, left fusiform gyrus, and left amygdala (F(1, 180) = 5.460 - 10.317, p < 0.05, partial eta squared = 0.029 - 0.054). The CD participants had smaller GMV in these regions than the TD participants (MCD - MTD = [-614.898] mm3 - [-53.461] mm3).

Conclusions

Altered GMV within specific regions may serve as a biomarker for the development of CD in adolescents. Clinical work can potentially target these biomarkers to treat adolescents with CD.

Larger left hippocampal presubiculum is associated with lower risk of antisocial behavior in healthy adults with childhood conduct history

Conduct Disorder (CD) is defined as aggressive, antisocial, and rule-breaking behavior during childhood. It is a major risk factor for developing antisocial personality disorder (ASPD) in adulthood. However, nearly half the CDs do not develop ASPD. Identification of reversion factors seems crucial for proper interventions. We identified 40 subjects with childhood history of CD (CC) and 1166 control subjects (HC) from Human Connectome Project. Their psychiatric, emotional, impulsivity, and personality traits were extracted. An emotion recognition task-fMRI analysis was done. We also did subregion analysis of hippocampus and amygdala in 35 CC and 69 demographically matched HCs. CC subjects scored significantly higher in antisocial-related evaluations. No differences in task-fMRI activation of amygdala and hippocampus were observed. CCs had larger subfields of the left hippocampus: presubiculum, CA3, CA4, and dentate gyrus. Further, an interaction model revealed a significant presubiculum volume × group association with antisocial, aggression, and agreeableness scores. Our study shows that healthy young adults with a prior history of CD still exhibit some forms of antisocial-like behavior with larger left hippocampal subfields, including presubiculum that also explains the variability in antisocial behavior. These larger left hippocampal subfield volumes may play a protective role against CD to ASPD conversion.

Cerebellar Grey Matter Volumes in Reactive Aggression and Impulsivity in Healthy Volunteers

Several lines of evidence point towards the involvement of the cerebellum in reactive aggression. In addition to the posterior cerebellar hemisphere, the vermis has been suggested to play a prominent role in impulse regulation. In the present study, we set out to further examine the relationships between cerebellar grey matter volumes, aggression, and impulsivity in 201 healthy volunteers. 3 T structural magnetic resonance imaging scans were acquired to investigate grey matter volumes of the cerebellar vermis and the anterior and posterior lobules. Aggression was assessed with the Buss-Perry Aggression Questionnaire and impulsivity was measured with the Barratt Impulsiveness Scale-11. Results showed that impulsivity was positively associated with grey matter volumes of the cerebellar vermis and inversely correlated with grey matter volumes of the right posterior lobule. In addition, smaller volumes of the right posterior lobules were associated with higher physical aggression. Exploratory analyses indicated that for the right hemisphere, this association was driven by grey matter volumes of lobules VIIb and VIIIa. Our findings provide correlational evidence in healthy volunteers for the involvement of the cerebellar vermis and posterior lobules in a cortico-limbic-cerebellar circuit of aggression.

Disrupted functional networks within white-matter served as neural features in adolescent patients with conduct disorder

BACKGROUND

Conduct disorder (CD) has been conceptualized as a psychiatric disorder associated with white-matter (WM) structural abnormalities. Although diffusion tensor imaging could identify WM structural architecture changes, it cannot characterize functional connectivity (FC) within WM. Few studies have focused on disentangling the WM dysfunctions in CD patients by using functional magnetic resonance imaging (fMRI).

METHODS

The resting-state fMRI data were first obtained from both adolescent CD and typically developing (TD) controls. A voxel-based clustering analysis was utilized to identify the large-scale WM FC networks. Then, we examined the disrupted WM network features in CD, and further investigated whether these features could predict the impulsive symptoms in CD using support vector regression prediction model.

RESULTS

We identified 11 WM functional networks. Compared with TDs, CD patients showed increased FCs between occipital network (ON) and superior temporal network (STN), between orbitofrontal network (OFN) and corona radiate network (CRN), as well as between deep network and CRN. Further, the disrupted FCs between ON and STN and between OFN and CRN were significantly negatively associated with non-planning impulsivity scores in CD. Moreover, the disrupted WM networks could be served as features to predict the motor impulsivity scores in CD.

CONCLUSIONS

Our results provided further support on the existence of WM functional networks and could extended our knowledge about the WM functional abnormalities related with emotional and perception processing in CD patients from the view of WM dysfunction.

Structural abnormalities in adolescents with conduct disorder and high versus low callous unemotional traits

There may be distinct conduct disorder (CD) etiologies and neural morphologies in adolescents with high callous unemotional (CU) traits versus low CU traits. Here, we employed surface-based morphometry methods to investigate morphological differences in adolescents diagnosed with CD [42 with high CU traits (CD-HCU) and 40 with low CU traits (CD-LCU)] and healthy controls (HCs, N = 115) in China. Whole-brain analyses revealed significantly increased cortical surface area (SA) in the left inferior temporal cortex and the right precuneus, but decreased SA in the left superior temporal cortex in the CD-LCU group, compared with the HC group. There were no significant cortical SA differences between the CD-HCU and the HC groups. Compared to the CD-HCU group, the CD-LCU group had a greater cortical thickness (CT) in the left rostral middle frontal cortex. Region-of-interest analyses revealed significant group differences in the right hippocampus, with CD-HCU group having lower right hippocampal volumes than HCs. We did not detect significant group differences in the amygdalar volume, however, the right amygdalar volume was found to be a significant moderator of the correlation between CU traits and the proactive aggression in CD patients. The present results suggested that the manifestations of CD differ between those with high CU traits versus low CU traits, and underscore the importance of sample characteristics in understanding the neural substrates of CD.

The relationship between adolescents' externalizing and internalizing symptoms and brain development over a period of three years

BACKGROUND

Adolescence is a crucial period for both brain maturation and the emergence of mental health disorders. Associations between brain morphology and internalizing/externalizing symptomatology have been identified in clinical or at-risk samples, but age-related developmental differences were rarely considered. The current study investigated the longitudinal relationship between internalizing/externalizing symptoms and brain development in the absence of psychiatric disorders during early and late adolescence.

METHODS

98 healthy adolescents within two cohorts (younger: 9 years, older: 12 years) participated in annual assessments for three years; a clinical assessment measuring their externalizing and internalizing symptoms (SDQ) and an MRI assessment measuring their brain volume and white matter microstructure, including fractional anisotropy (FA), mean diffusivity (MD) and average path length.

RESULTS

Linear mixed effect models and cross-lagged panel models showed that larger subcortical gray matter volume predicted more externalizing symptoms in older adolescents whereas decreases of subcortical gray matter volume predicted more externalizing symptoms for younger adolescents. Additionally, longer average white matter path length predicted more externalizing symptoms for older adolescents, while decreases in cerebral white matter volume were predictive of more externalizing symptoms for younger adolescents. There were no predictive effects for internalizing symptoms, FA or MD.

CONCLUSIONS

Delays in subcortical brain maturation, in both early and late adolescence, are associated with increases in externalizing behavior which indicates a higher risk for psychopathology and warrants further investigations.

Best Practices in Structural Neuroimaging of Neurodevelopmental Disorders

Structural magnetic resonance imaging (sMRI) offers immense potential for increasing our understanding of how anatomical brain development relates to clinical symptoms and functioning in neurodevelopmental disorders. Clinical developmental sMRI may help identify neurobiological risk factors or markers that may ultimately assist in diagnosis and treatment. However, researchers and clinicians aiming to conduct sMRI studies of neurodevelopmental disorders face several methodological challenges. This review offers hands-on guidelines for clinical developmental sMRI. First, we present brain morphometry metrics and review evidence on typical developmental trajectories throughout adolescence, together with atypical trajectories in selected neurodevelopmental disorders. Next, we discuss challenges and good scientific practices in study design, image acquisition and analysis, and recent options to implement quality control. Finally, we discuss choices related to statistical analysis and interpretation of results. We call for greater completeness and transparency in the reporting of methods to advance understanding of structural brain alterations in neurodevelopmental disorders.

Neurodevelopmental Trajectories in Children With Internalizing, Externalizing and Emotion Dysregulation Symptoms

INTRODUCTION

Childhood and adolescence are crucial periods for brain and behavioral development. However, it is not yet clear how and when deviations from typical brain development are related to broad domains of psychopathology.

METHODS

Using three waves of neuroimaging data within the population-based Generation R Study sample, spanning a total age range of 6-16 years, we applied normative modeling to establish typical development curves for (sub-)cortical volume in 37 brain regions, and cortical thickness in 32 brain regions. Z-scores representing deviations from typical development were extracted and related to internalizing, externalizing and dysregulation profile (DP) symptoms.

RESULTS

Normative modeling showed regional differences in developmental trajectories. Psychopathology symptoms were related to negative deviations from typical development for cortical volume in widespread regions of the cortex and subcortex, and to positive deviations from typical development for cortical thickness in the orbitofrontal, frontal pole, pericalcarine and posterior cingulate regions of the cortex.

DISCUSSION

Taken together, this study charts developmental curves across the cerebrum for (sub-)cortical volume and cortical thickness. Our findings show that psychopathology symptoms, are associated with widespread differences in brain development, in which those with DP symptoms are most heavily affected.

Multimodal Ensemble Deep Learning to Predict Disruptive Behavior Disorders in Children

Oppositional defiant disorder and conduct disorder, collectively referred to as disruptive behavior disorders (DBDs), are prevalent psychiatric disorders in children. Early diagnosis of DBDs is crucial because they can increase the risks of other mental health and substance use disorders without appropriate psychosocial interventions and treatment. However, diagnosing DBDs is challenging as they are often comorbid with other disorders, such as attention-deficit/hyperactivity disorder, anxiety, and depression. In this study, a multimodal ensemble three-dimensional convolutional neural network (3D CNN) deep learning model was used to classify children with DBDs and typically developing children. The study participants included 419 females and 681 males, aged 108–131 months who were enrolled in the Adolescent Brain Cognitive Development Study. Children were grouped based on the presence of DBDs (n = 550) and typically developing (n = 550); assessments were based on the scores from the Child Behavior Checklist and on the Schedule for Affective Disorders and Schizophrenia for School-age Children-Present and Lifetime version for DSM-5. The diffusion, structural, and resting-state functional magnetic resonance imaging (rs-fMRI) data were used as input data to the 3D CNN. The model achieved 72% accuracy in classifying children with DBDs with 70% sensitivity, 72% specificity, and an F1-score of 70. In addition, the discriminative power of the classifier was investigated by identifying the cortical and subcortical regions primarily involved in the prediction of DBDs using a gradient-weighted class activation mapping method. The classification results were compared with those obtained using the three neuroimaging modalities individually, and a connectome-based graph CNN and a multi-scale recurrent neural network using only the rs-fMRI data.

Association of subcortical gray-matter volumes with life-course-persistent antisocial behavior in a population-representative longitudinal birth cohort

Neuropsychological evidence supports the developmental taxonomy theory of antisocial behavior, suggesting that abnormal brain development distinguishes life-course-persistent from adolescence-limited antisocial behavior. Recent neuroimaging work confirmed that prospectively-measured life-course-persistent antisocial behavior is associated with differences in cortical brain structure. Whether this extends to subcortical brain structures remains uninvestigated. This study compared subcortical gray-matter volumes between 672 members of the Dunedin Study previously defined as exhibiting life-course-persistent, adolescence-limited or low-level antisocial behavior based on repeated assessments at ages 7-26 years. Gray-matter volumes of 10 subcortical structures were compared across groups. The life-course-persistent group had lower volumes of amygdala, brain stem, cerebellum, hippocampus, pallidum, thalamus, and ventral diencephalon compared to the low-antisocial group. Differences between life-course-persistent and adolescence-limited individuals were comparable in effect size to differences between life-course-persistent and low-antisocial individuals, but were not statistically significant due to less statistical power. Gray-matter volumes in adolescence-limited individuals were near the norm in this population-representative cohort and similar to volumes in low-antisocial individuals. Although this study could not establish causal links between brain volume and antisocial behavior, it constitutes new biological evidence that all people with antisocial behavior are not the same, supporting a need for greater developmental and diagnostic precision in clinical, forensic, and policy-based interventions.

Executive function mediates the prospective association between neurostructural differences within the central executive network and anti-social behavior after childhood traumatic brain injury

BACKGROUND

Despite increasing evidence of a link between early life brain injury and anti-social behavior, very few studies have assessed factors that explain this association in children with traumatic brain injury (TBI). One hypothesis suggests that childhood TBI elevates risk for anti-social behavior via disruption to anatomically distributed neural networks implicated in executive functioning (EF). In this longitudinal prospective study, we employed high-resolution structural neuroimaging to (a) evaluate the impact of childhood TBI on regional morphometry of the central executive network (CEN) and (b) evaluate the prediction that lower EF mediates the prospective relationship between structural differences within the CEN and postinjury anti-social behaviors.

METHODS

This study involved 155 children, including 112 consecutively recruited, hospital-confirmed cases of mild-severe TBI and 43 typically developing control (TDC) children. T1-weighted brain magnetic resonance imaging (MRI) sequences were acquired sub-acutely in a subset of 137 children [TBI: n = 103; TDC: n = 34]. All participants were evaluated using direct assessment of EF 6 months postinjury, and parents provided ratings of anti-social behavior 12 months postinjury.

RESULTS

Severe TBI was associated with postinjury volumetric differences within the CEN and its putative hub regions. When compared with TD controls, the TBI group had significantly worse EF, which was associated with more frequent anti-social behaviors and abnormal CEN morphometry. Mediation analysis indicated that reduced EF mediated the prospective association between postinjury volumetric differences within the CEN and more frequent anti-social behavior.

CONCLUSIONS

Our longitudinal prospective findings suggest that detection of neurostructural abnormalities within the CEN may aid in the early identification of children at elevated risk for postinjury executive dysfunction, which may in turn contribute to chronic anti-social behaviors after early life brain injury. Findings underscore the potential value of early surveillance and preventive measures for children presenting with neurostructural and/or neurocognitive risk factors.

Decreased interhemispheric resting-state functional connectivity in male adolescents with conduct disorder

Conduct disorder (CD) is a common psychiatric disorder defined by a repetitive and persistent pattern of aggressive and antisocial behaviors. Although numerous task-based and resting-state functional magnetic resonance imaging (rsfMRI) studies have emphasized the disrupted functional connectivity in CD, the CD-related alterations in functional interactions between the bilateral cerebral hemispheres are rarely investigated directly. In this study, a voxel-mirrored homotopic connectivity (VMHC) method based on rsfMRI was employed for the first time to examine the abnormalities of interhemispheric functional connectivity in patients with CD. The VMHC was compared between eighteen pure CD patients and eighteen typically developing (TD) healthy controls. In CD patients, reduced homotopic connectivity was observed relative to TDs in the middle occipital gyrus (MOG), pre- and postcentral gyrus, rolandic operculum and paracentral lobe (PCL) which were the components of visual and motor networks. Furthermore, the VMHC of the MOG and PCL was found to be negatively correlated with clinical scores in the CD group. Moreover, the regions with altered VMHC exhibited a relative good and robust ability to discriminate CD patients from TDs. This study provided a novel angle to identify the important role of interhemispheric coordination in the pathophysiology underlying CD and further indicated that the aberrant homotopic connectivity could be a potential clinical neural marker for CD diagnosis.

Altered dynamic regional homogeneity in patients with conduct disorder

Conduct disorder (CD) is a psychiatric condition characterized by severe aggressive and antisocial behaviors. Prior neuroimaging work reported that CD is associated with abnormal resting-state local intrinsic brain activity (IBA). However, few studies detected the time-varying brain activity patterns in CD. In this study, eighteen adolescent patients with CD and 18 typically developing controls underwent resting-state functional magnetic resonance imaging scans. We then compared the dynamic characteristics of IBA by calculating the dynamic regional homogeneity (dReHo) through a sliding-window approach between the two groups, and the correlations between the dReHo variability and clinical symptoms in CD were further examined. Moreover, the statistical between-group differences in dReHo were selected as classification features to help distinguish CD patients from controls by adopting a linear support vector machine (SVM) classifier. CD patients showed increased dReHo variability in the left precuneus, right postcentral gyrus, right precentral gyrus, left middle cingulate gyrus, and left paracentral lobule compared to controls, and dReHo variability in the left precuneus was significantly positively associated with impulsiveness scores in CD patients. Importantly, SVM combined with the leave-one-out cross-validation method results demonstrated that 75% (p < 0.001) subjects were correctly classified with sensitivity of 61% and specificity of 89%. Our results provided the initial evidence that CD is characterized by abnormal dynamic IBA patterns, giving novel insights into the neuropathological mechanisms of CD. Further, our findings exhibited that the dReHo variability may distinguish CD patients from controls with high accuracy.

Structural Brain Development and Aggression: A Longitudinal Study in Late Childhood

This longitudinal study examined the neurodevelopmental correlates of aggression in children, focusing on structural brain properties. A community sample of 110 (60 females) children participated at age 8 years and again at age 10 years. Brain structure was assessed by using magnetic resonance imaging (MRI), and parents reported on child aggression using the Child Behavior Checklist. Analyses examined the relationship between aggression and development of volume of subcortical regions, cortical thickness, and subcortical-cortical structural coupling. Females with relatively high aggression exhibited reduced right hippocampal growth over time. Across males and females, aggression was associated with amygdala- and hippocampal-cortical developmental coupling, with findings for amygdala-cortical coupling potentially indicating reduced top-down prefrontal control of the amygdala in those with increasing aggression over time. Findings suggest that aggressive behaviors may be associated with alterations in normative brain development; however, results were not corrected for multiple comparisons and should be interpreted with caution.

Sex differences in medial prefrontal and parietal cortex structure in children with disruptive behavior

Sex differences in brain structure in children with disruptive behavior disorders (DBD) remain poorly understood. This study examined sex differences in gray matter volume in children with DBD in a priori regions-of-interest implicated in the pathophysiology of disruptive behavior. We then conducted a whole-brain analysis of cortical thickness to examine sex differences in regions not included in our hypothesis. Exploratory analyses investigated unique associations between structure, and dimensional measures of severity of disruptive behavior and callous-unemotional traits. This cross-sectional study included 88 children with DBD (30 females) aged 8-16 years and 50 healthy controls (20 females). Structural MRI data were analyzed using surface-based morphometry to test for interactions between sex and group. Multiple-regression analyses tested for sex-specific associations between structure, callous-unemotional traits, and disruptive behavior severity. Boys with DBD showed reduced gray matter volume in the left ventromedial prefrontal cortex (vmPFC) and reduced cortical thickness in the supramarginal gyrus, but not girls compared to respective controls. Dimensional analyses revealed associations between sex, callous-unemotional traits, and disruptive behavior for amygdala and vmPFC volume, and ventrolateral prefrontal cortex cortical thickness. Sex-specific differences in prefrontal structures involved in emotion regulation may support identification of neural biomarkers of disruptive behavior to inform target-based treatments.

Volumetric brain abnormalities in adolescents with conduct disorder with and without attention deficit-hyperactivity disorder: a case control study

Background

Conduct disorder (CD) is a prevalent psychiatric disorder in youth with heterogeneous presentations and hazardous outcomes on family and society. Identifying potential biological markers may help in better understanding and management of the problem. This work aims to explore the potential volumetric brain abnormalities in an Arab-Egyptian sample of conduct disordered youth with and without comorbid ADHD. A total of 27 subjects with conduct disorder, 14 of which also fulfilled the criteria of ADHD, in addition to twenty healthy subjects were recruited. A validated Arabic version of the Mini International Neuropsychiatric Interview for Children and Adolescents “M.I.N.I-Kid” was carried out. MRI acquisition was performed on 1.5 T Toshiba MRI scanner. Cortical reconstruction and automatic volumetric segmentation were performed with the Freesurfer image analysis suite.

Results

Youth with CD, with and without ADHD, showed significantly lower cortical thicknesses and smaller subcortical volumes in most of the hemispheric areas. When the two patient groups were compared, youth with CD + ADHD had significantly greater cortical thicknesses but smaller subcortical volumes as compared to youth with CD only.

Conclusions

Conduct disorder, comorbid with ADHD, might prove to be a distinct phenotypic entity with different biological substrates, and hence different needed management, from CD without comorbid ADHD.

More than just statics: Abnormal dynamic amplitude of low-frequency fluctuation in adolescent patients with pure conduct disorder

BACKGROUND

The human brain activity is inherently dynamic over time. Conventional neuroimaging studies have reported abnormalities of static intrinsic brain activity or connectivity in adolescent patients with conduct disorder (CD). Little is known, however, regarding the temporal dynamics alterations of brain activity in CD.

METHODS

In this study, resting-state functional magnetic resonance imaging examinations were performed on adolescent patients with pure CD and age-matched typically developing (TD) controls. The dynamic amplitude of low-frequency fluctuation (dALFF) was first measured using a sliding-window method. The temporal variability (TV) was then quantified as the variance of dALFF over time and compared between the two groups. Further, the relationships between aberrant TV of dALFF and clinical features were evaluated.

RESULTS

CD patients showed reduced brain dynamics (less temporal variability) in the default-mode network, frontal-limbic cortices, sensorimotor areas, and visual regions which are involved in cognitive, emotional and perceptional processes. Importantly, receiver operating characteristic curve analysis revealed that regions with altered TV of dALFF exhibited a better ability to distinguish CD patients than the results from static ALFF in the current data set.

CONCLUSIONS

Our findings extended previous work by providing a novel perspective on the neural mechanisms underlying adolescent patients with CD and demonstrated that the altered dynamic local brain activity may be a potential biomarker for CD diagnosis.

Gray Matter Changes in the Orbitofrontal-Paralimbic Cortex in Male Youths With Non-comorbid Conduct Disorder

Conduct disorder is one of the most common developmental psychiatric disorders which is characterized by persistent aggressive and antisocial behaviors during childhood or adolescence. Previous neuroimaging studies have investigated the neural correlates underlying CD and demonstrated several constructive findings. However, Individuals with CD are at high risk for comorbidities, which might give rise to the inconsistencies of existed findings. It remains unclear which neuroanatomical abnormalities are specifically related to CD without comorbidities. Using structural magnetic resonance imaging (sMRI) data of 69 CD and 69 typically developing (TD) male youths (aged 14–17 years), the present study aims at investigating gray matter volume alterations of non-comorbid CD (i.e., not comorbid with attention deficit hyperactivity disorder, substance abuse disorder, anxiety or depression). We also examined how regional gray matter volumes were related to callous-unemotional (CU) traits and conduct problems in the CD group. The whole-brain analysis revealed decreased gray matter volumes in the right pre-postcentral cortex, supramarginal gyrus and right putamen in CD youths compared with TD youths. The region-of-interest analyses showed increased gray matter volumes in the superior temporal gyrus (STG) and right orbitofrontal cortex (OFC) in CD youths. Correlation analysis found that gray matter volume in the left amygdala was negatively correlated with CU traits in CD participants. These results demonstrated that gray matter volume in the orbitofrontal-paralimbic cortex, including OFC, STG and amygdala, might characterize the male youths with non-comorbid CD and might contribute to different severe forms and trajectories of CD.

Reduced gray matter volume in male adolescent violent offenders

Background

Previous studies reported that reduced gray matter volume (GMV) was associated with violent-related behaviors. However, the previous studies were conducted on adults and no study has studied the association between GMV and violent behaviors on adolescents. The purpose of the study was to investigate GMV’s effects in adolescent violent offenders based on a Chinese Han population, which can address the problem of possible confounding factors in adult studies.

Methods

We recruited 30 male adolescent violent offenders and 29 age- and sex-matched healthy controls (HCs). Differences in both whole-brain and GMV were evaluated using voxel-based morphometry (VBM). We assessed the accuracy of VBM using the receiver operating characteristic curve (ROC) and discriminant analysis.

Results

Compared with HCs, the male adolescent offenders showed significantly reduced GMV in five cortical and subcortical brain regions, including the olfactory cortex, amygdala, middle temporal gyrus and inferior parietal lobe in the left hemisphere, as well as the right superior temporal gyrus. Both ROC curve and discriminate analyses showed that these regions had relatively high sensitivities (58.6%–89.7%) and specificities (58.1%–74.2%) with 76.7% classification accuracy.

Conclusions

Our results indicated that reduced volume in the frontal-temporal-parietal-subcortical circuit may be closely related to violent behaviors in male adolescents, which might be an important biomarker for detecting violent behaviors in male adolescents.

Using biological factors to individualize interventions for youth with conduct problems: Current state and ethical issues

A growing body of evidence suggests that biological factors such as genes, hormone levels, brain structure, and brain functioning influence the development and trajectory of conduct problems in youth. In addition, biological factors affect how individuals respond to the environment, including how individuals respond to programs designed to prevent or treat conduct problems. Programs designed to reduce behavior problems in youth would have the greatest impact if they were targeted toward youth who need it the most (e.g., who are mostly likely to demonstrate persistent behavior problems) as well as youth who may benefit the most from the program. Biological information may improve our ability to make decisions about which type or level of intervention is best for a particular child, thus maximizing overall effectiveness, but it also raises a number of ethical concerns. These include the idea that we may be providing fewer services to some youth based on biological factors, and that information about biological risk could potentially lead to discrimination or labeling. In this article, I discuss the risks and benefits of using biological information to individualize interventions for youth with conduct problems.

Callous and uncaring traits are associated with reductions in amygdala volume among youths with varying levels of conduct problems

BACKGROUND

The emergence of callous unemotional (CU) traits, and associated externalizing behaviors, is believed to reflect underlying dysfunction in the amygdala. Studies of adults with CU traits or psychopathy have linked characteristic patterns of amygdala dysfunction to reduced amygdala volume, but studies in youths have not thus far found evidence of similar amygdala volume reductions. The current study examined the association between CU traits and amygdala volume by modeling CU traits and externalizing behavior as independent continuous variables, and explored the relative contributions of callous, uncaring, and unemotional traits.

METHODS

CU traits and externalizing behavior problems were assessed in 148 youths using the Inventory of Callous Unemotional Traits (ICU) and the Child Behavior Checklist (CBCL). For a subset of participants (n = 93), high-resolution T1-weighted images were collected and volume estimates for the amygdala were extracted.

RESULTS

Analyses revealed that CU traits were associated with increased externalizing behaviors and decreased bilateral amygdala volume. These results were driven by the callous and uncaring sub-factors of CU traits, with unemotional traits unrelated to either externalizing behaviors or amygdala volume. Results persisted after accounting for covariation between CU traits and externalizing behaviors. Bootstrap mediation analyses indicated that CU traits mediated the relationship between reduced amygdala volume and externalizing severity.

CONCLUSIONS

These findings provide evidence that callous-uncaring traits account for reduced amygdala volume among youths with conduct problems. These findings provide a framework for further investigation of abnormal amygdala development as a key causal pathway for the development of callous-uncaring traits and conduct problems.

Towards interpretable machine learning models for diagnosis aid: A case study on attention deficit/hyperactivity disorder

Attention Deficit/Hyperactivity Disorder (ADHD) is a neurodevelopmental disorder that has heavy consequences on a child's wellbeing, especially in the academic, psychological and relational planes. The current evaluation of the disorder is supported by clinical assessment and written tests. A definitive diagnosis is usually made based on the DSM-V criteria. There is a lot of ongoing research on ADHD, in order to determine the neurophysiological basis of the disorder and to reach a more objective diagnosis. The advent of Machine Learning (ML) opens up promising prospects for the development of systems able to predict a diagnosis from phenotypic and neuroimaging data. This was the reason why the ADHD-200 contest was launched a few years ago. Based on the publicly available ADHD-200 collection, participants were challenged to predict ADHD with the best possible predictive accuracy. In the present work, we propose instead a ML methodology which primarily places importance on the explanatory power of a model. Such an approach is intended to achieve a fair trade-off between the needs of performance and interpretability expected from medical diagnosis aid systems. We applied our methodology on a data sample extracted from the ADHD-200 collection, through the development of decision trees which are valued for their readability. Our analysis indicates the relevance of the limbic system for the diagnosis of the disorder. Moreover, while providing explanations that make sense, the resulting decision tree performs favorably given the recent results reported in the literature.

The structural brain correlates of callous-unemotional traits in incarcerated male adolescents

Youth with severe conduct problems impose a significant cost on society by engaging in high levels of antisocial and aggressive behavior. Within this group, adolescents with high levels of callous- unemotional traits have been found to exhibit more severe and persistent patterns of antisocial behavior than youth with severe conduct problems but normative levels of callous-unemotional traits. Existing neuroimaging studies, along with theoretical accounts of psychopathology, suggest that dysfunction within the paralimbic cortex and limbic system may underlie elevated levels of callous-unemotional traits. The present study examines this hypothesis by investigating gray matter correlates associated with callous-unemotional traits. A sample of incarcerated male adolescents (N = 269), were assessed using voxel-based morphometry. Callous-unemotional traits were assessed using the Inventory of Callous-Unemotional traits (Frick 2004). Total callous-unemotional traits were negatively correlated with anterior temporal lobe gray matter volume (GMV). Callous traits in particular exhibited a reliable negative correlation with gray matter volume in nearly every paralimbic brain region examined. Uncaring traits were positively correlated with GMV in the orbitofrontal and anterior cingulate cortices. These findings demonstrate specific neural features within the paralimbic cortex and limbic system that accompany elevated callous-unemotional traits and serves to expand our understanding of pathophysiological mechanisms that may give rise to severe conduct problems in youth.

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Total callous-unemotional traits were negatively correlated with anterior temporal lobe gray matter volume (GMV).

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Callous traits negatively correlated with GMV in nearly every paralimbic regions examined.

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Uncaring traits were positively correlated with GMV in the orbitofrontal and anterior cingulate cortices.

Prenatal maternal anxiety and children's brain structure and function: A systematic review of neuroimaging studies

BACKGROUND

Maternal anxiety disorders are common during pregnancy and postpartum, and are associated with increased behaviour problems and risk of mental health difficulties in children. Understanding alterations in brain structure and function associated with maternal anxiety may help elucidate potential mechanisms via which high maternal anxiety could affect children.

METHODS

We conducted a systematic review of extant research studying the associations between prenatal anxiety and children's brain structure and function, as assessed through neuroimaging. Data were gathered in accordance with the PRISMA review guidelines.

RESULTS

Ten articles were identified, and all found a significant association between antenatal maternal anxiety and child neurodevelopment. Studies vary considerably in their methods with five studies employing electroencephalography (EEG), one using magnetoencephalography (MEG), and the rest employing magnetic resonance imaging (MRI).

LIMITATIONS

The heterogeneity of neuroimaging techniques undertaken by the reviewed studies precluded a meta-analysis from being performed. The applicability of this systematic review to clinical practice is also limited given that the studies examined children across a wide age range (neonates to 17 years).

CONCLUSIONS

From early infancy to late adolescence, findings suggest alterations of brain structure and function in frontal, temporal, and limbic areas in children born to mothers who experienced prenatal anxiety. These brain abnormalities may underlie associations between prenatal anxiety and children's behaviour, though more research incorporating neuroimaging and behavioural data is necessary to determine this.

Altered Neuronal Responses During an Affective Stroop Task in Adolescents With Conduct Disorder

Conduct disorder (CD) is a psychiatric disorder of childhood and adolescence which has been linked to deficient emotion processing and regulation. The behavioral and neuronal correlates targeting the interaction of emotion processing and response inhibition are still under investigation. Whole-brain event-related fMRI was applied during an affective Stroop task in 39 adolescents with CD and 39 typically developing adolescents (TD). Participants were presented with an emotional stimulus (negative/neutral) followed by a Stroop task with varying cognitive load (congruent/incongruent/blank trials). fMRI analysis included standard preprocessing, region of interest analyses (amygdala, insula, ventromedial prefrontal cortex) and whole-brain analyses based on a 2(group) × 2(emotion) × 3(task) full-factorial ANOVA. Adolescents with CD made significantly more errors, while reaction times did not significantly differ compared to TD. Additionally, we observed a lack of downregulation of left amygdala activity in response to incongruent trials and increased anterior insula activity for CD relative to TD during affective Stroop task processing [cluster-level family-wise error-corrected (p < 0.05)]. Even though no three-way interaction (group × emotion × task) interaction was detected, the findings presented still provide evidence for altered neuronal underpinnings of the interaction of emotion processing and response inhibition in CD. Moreover, our results may corroborate previous evidence of emotion dysregulation as a core dysfunction in CD. Future studies shall focus on investigating the interaction of emotion processing and response inhibition in CD subgroups (e.g., variations in callous-unemotional traits, impulsivity, or anxiety).

Longitudinal structural brain development and externalizing behavior in adolescence

BACKGROUND

Cross-sectional studies report relations between externalizing behavior and structural abnormalities in cortical thickness of prefrontal regions and volume reductions in subcortical regions. To understand how these associations emerge and develop, longitudinal designs are pivotal.

METHOD

In the current longitudinal study, a community sample of children, adolescents and young adults (N = 271) underwent magnetic resonance imaging (MRI) in three biennial waves (680 scans). At each wave, aspects of externalizing behavior were assessed with parent-reported aggression and rule-breaking scores (Child Behavior Checklist), and self-reported aggression scores (Buss-Perry Aggression Questionnaire). Regions of interest (ROIs) were selected based on prior research: dorsolateral prefrontal (dlPFC), orbitofrontal (OFC), anterior cingulate cortex (ACC), insula, and parahippocampal cortex, as well as subcortical regions. Linear mixed models were used to assess the longitudinal relation between externalizing behavior and structural brain development. Structural covariance analyses were employed to identify whether longitudinal relations between ROIs (maturational coupling) were associated with externalizing behavior.

RESULTS

Linear mixed model analyses showed a negative relation between parent-reported aggression and right hippocampal volume. Moreover, this longitudinal relation was driven by change in hippocampal volume and not initial volume of hippocampus at time point 1. Exploratory analyses showed that stronger maturational coupling between prefrontal regions, the limbic system, and striatum was associated with both low and high externalizing behavior.

CONCLUSIONS

Together, these findings reinforce the hypothesis that altered structural brain development coincides with development of more externalizing behavior. These findings may guide future research on normative and deviant development of externalizing behavior.

Genetic influences on conduct disorder

Conduct disorder (CD) is a moderately heritable psychiatric disorder of childhood and adolescence characterized by aggression toward people and animals, destruction of property, deceitfulness or theft, and serious violation of rules. Genome-wide scans using linkage and association methods have identified a number of suggestive genomic regions that are pending replication. A small number of candidate genes (e.g., GABRA2, MAOA, SLC6A4, AVPR1A) are associated with CD related phenotypes across independent studies; however, failures to replicate also exist. Studies of gene-environment interplay show that CD genetic predispositions also contribute to selection into higher-risk environments, and that environmental factors can alter the importance of CD genetic factors and differentially methylate CD candidate genes. The field's understanding of CD etiology will benefit from larger, adequately powered studies in gene identification efforts; the incorporation of polygenic approaches in gene-environment interplay studies; attention to the mechanisms of risk from genes to brain to behavior; and the use of genetically informative data to test quasi-causal hypotheses about purported risk factors.

Brain structure abnormalities in young women who presented conduct disorder in childhood/adolescence

The phenotype and genotype of antisocial behavior among females are different from those among males. Previous studies have documented structural brain alterations in males with antisocial behavior, yet little is known about the neural correlates of female antisocial behavior. The present study examined young women who had presented conduct disorder (CDW) prior to age 15 to determine whether brain abnormalities are present in adulthood and whether the observed abnormalities are associated with comorbid disorders or maltreatment that typically characterize this population. Using magnetic resonance imaging and voxel-based morphometry, we compared gray matter volumes (GMV) of 31 women who presented CD by midadolescence and 25 healthy women (HW), age, on average, 23 years. Participants completed structured, validated interviews to diagnose mental disorders, and validated questionnaires to document physical and sexual abuse. Relative to HW, CDW presented increased GMV in the left superior temporal gyrus that was associated with past alcohol and drug dependence, current use of alcohol and drugs, and current anxiety and depression symptoms and maltreatment. Additionally, CDW displayed reduced GMV in lingual gyrus, hippocampus, and anterior cingulate cortex that was associated with past comorbid disorders, current alcohol and drugs use, current anxiety and depression symptoms, and maltreatment. The CDW also presented reduced total GMV that was associated with past comorbid disorders and current anxiety/depression symptoms. Alterations of brain structure were observed among young adult females with prior CD, relative to HW, all of which were associated with internalizing and externalizing disorders and maltreatment that typically accompany CD.

Default mode network activity and neuropsychological profile in male children and adolescents with attention deficit hyperactivity disorder and conduct disorder

It is known that patients with Attention Deficit and Hyperactivity disorder (ADHD) and Conduct disorder (CD) commonly shows greater symptom severity than those with ADHD alone and worse outcomes. This study researches whether Default mode network (DMN) is altered in adolescents with ADHD + CD, relative to ADHD alone and controls or not. Ten medication-naïve boys with ADHD + CD, ten medication-naïve boys with ADHD and 10-age-matched typically developing (TD) controls underwent functional magnetic resonance imaging (fMRI) scans in the resting state and neuropsychological tasks such as the Wisconsin Card Sorting Test (WCST), Stroop Test TBAG Form (STP), Auditory Verbal learning Test (AVLT), Visual Auditory Digit Span B (VADS B) were applied to all the subjects included. fMRI scans can be used only nine patients in each groups. The findings revealed group differences between cingulate cortex and primary mortor cortex; cingulate cortex and somatosensory association cortex; angular gyrus (AG) and dorsal posterior cingulate cortex, in these networks increased activity was observed in participants with ADHD + CD compared with the ADHD. We found that lower resting state (rs)-activity was observed between left AG and dorsal posterior cingulate cortex, whereas higher rs-activity connectivity were detected between right AG and somatosensory association cortex in ADHD relative to the ones with ADHD + CD. In neuropsyhcological tasks, ADHD + CD group showed poor performance in WISC-R, WCST, Stroop, AVLT tasks compared to TDs. The ADHD + CD group displayed rs-functional abnormalities in DMN. Our results suggest that abnormalities in the intrinsic activity of resting state networks may contribute to the etiology of CD and poor prognosis of ADHD + CD.

Amygdala volume mediates the relationship between externalizing symptoms and daily smoking in adolescence: A prospective study

The current study examined amygdala and orbitofrontal cortex (OFC) volumes as mediators of the relationship between externalizing symptoms and daily smoking in adolescence. Externalizing behaviors are among the most robust predictors of adolescent smoking, and there is emerging evidence that volume reductions in the amygdala and OFC are associated with risk for substance misuse as well as aggressive, impulsive, and disinhibited tendencies. Using a prospective longitudinal design, we recruited 109 adolescents who provided data on brain volume and externalizing behaviors at age 12, and on smoking at age 18. Daily smoking at age 18 (n = 27) was predicted by externalizing behaviors (measured by the self-report Child Behavior Checklist, CBCL) as well as smaller right amygdala volumes. Right amygdala volumes mediated the relationship between externalizing symptoms and later smoking. These findings provide important insight into the neurobiological risk factors associated with adolescent smoking, and, more generally, into factors that may be associated with vulnerability to substance use disorders and related psychopathology.

Impulsive aggression and response inhibition in attention-deficit/hyperactivity disorder and disruptive behavioral disorders: Findings from a systematic review

BACKGROUND

Although impulsive aggression (IA) and dysfunctional response inhibition (RI) are hallmarks of attention-deficit/hyperactivity disorder (ADHD) and disrupted behavioral disorders (DBDs), little is known about their shared and distinct deviant neural mechanisms.

AIMS AND METHODS

Here, we selectively reviewed s/fMRI ADHD and DBD studies to identify disorder-specific and shared IA and RI aberrant neural mechanisms.

RESULTS

In ADHD, deviant prefrontal and cingulate functional activity was associated with increased IA. Structural alterations were most pronounced in the cingulate cortex. Subjects with DBDs showed marked cortico-subcortical dysfunctions. ADHD and DBDs share similar cortico-limbic structural and functional alterations. RI deficits in ADHD highlighted hypoactivity in the dorso/ventro-lateral PFC, insula, and striatum, while the paralimbic system was primarily dysfunctional in DBDs. Across disorders, extensively altered cortico-limbic dysfunctions underlie IA, while RI was mostly associated with aberrant prefrontal activity.

CONCLUSION

Control network deficits were evidenced across clinical phenotypes in IA and RI. Dysfunctions at any level within these cortico-subcortical projections lead to deficient cognitive-affective control by ascribing emotional salience to otherwise irrelevant stimuli. The clinical implications of these findings are discussed.

Attachment Security in Infancy: A Preliminary Study of Prospective Links to Brain Morphometry in Late Childhood

A large body of longitudinal research provides compelling evidence for the critical role of early attachment relationships in children’s social, emotional, and cognitive development. It is expected that parent–child attachment relationships may also impact children’s brain development, however, studies linking normative caregiving experiences and brain structure are scarce. To our knowledge, no study has yet examined the associations between the quality of parent–infant attachment relationships and brain morphology during childhood. The aim of this preliminary study was to investigate the prospective links between mother–infant attachment security and whole-brain gray matter (GM) volume and thickness in late childhood. Attachment security toward the mother was assessed in 33 children when they were 15 months old. These children were then invited to undergo structural magnetic resonance imaging at 10–11 years of age. Results indicated that children more securely attached to their mother in infancy had larger GM volumes in the superior temporal sulcus and gyrus, temporo-parietal junction, and precentral gyrus in late childhood. No associations between attachment security and cortical thickness were found. If replicated, these results would suggest that a secure attachment relationship and its main features (e.g., adequate dyadic emotion regulation, competent exploration) may influence GM volume in brain regions involved in social, cognitive, and emotional functioning through experience-dependent processes.

Hemispheric asymmetry of the frontolimbic cortex in young adults with borderline personality disorder

OBJECTIVE

Although the frontolimbic cortex has been implicated in borderline personality disorder (BPD), information about possible asymmetries in this region in patients with BPD is limited. This study aimed to examine whether frontolimbic cortex asymmetries differ between patients with BPD and healthy individuals.

METHODS

The brains of 30 young adult patients with BPD and 32 healthy control subjects were scanned with magnetic resonance imaging (MRI). The participants completed self-report scales assessing impulsivity, affect intensity and other psychological variables. Gray matter volume, surface area, and cortical thickness in regions of interest (ROIs), namely anterior insula (AI) and anterior cingulate cortex (ACC) were determined and the data were probed for hemisphere-group interactions.

RESULTS

Relative to controls, patients with BPD had reduced cortical thickness in left ACC and less surface area and gray matter volume in left AI. Significant group-hemisphere interactions were observed for gray matter volume and surface area of AI and for cortical thickness of ACC. Post hoc analysis showed that the BPD patients had greater frontolimbic cortex asymmetry than healthy controls; furthermore, greater asymmetry of AI&ACC correlated with a higher score in attention subscale of Barratt Impulsiveness Scale.

CONCLUSION

Patients with BPD have greater frontolimbic asymmetry than healthy individuals.

Disrupted small-world brain network topology in pure conduct disorder

OBJECTIVES

Conduct disorder (CD) is characterized by the violation of the rights of others or basic social rules and a repetitive, persistent pattern of antisocial and aggressive behaviors. A large number of functional and structural neuroimaging studies have identified widely abnormalities in specific brain regions in CD, but the alterations in the topological organization of functional networks among them remain largely unknown.

METHODS

Resting-state functional magnetic resonance imaging was applied to investigate the intrinsic functional connectivity in 18 pure CD patients and eighteen typically developing healthy controls. We first constructed the functional networks and then examined the CD-related alteration in topology properties using graph theoretical analysis.

RESULTS

Both the CD group and healthy controls exhibited small-world topology. However, the CD group showed decreased global and local efficiency. Changes in the nodal characteristics in CD group were found predominantly in the default-mode network, visual, and striatum regions. In addition, altered fronto-limbic-striatum network topology was found to have a relationship with clinical scores.

CONCLUSIONS

Our findings indicate the altered nodal topology of brain functional connectivity networks in CD.

SIGNIFICANCE

The results provide unequivocal evidence of a topological disruption in the brain networks that suggest some possible pathophysiological mechanisms underlying CD.

Neuroanatomical correlates of donating behavior in middle childhood

The neurobiological correlates of prosocial behavior are largely unknown. We examined brain structure and functional connectivity correlates of donating to a charity, a specific, costly, form of prosocial behavior. In 163 children, donating was measured using a promotional clip for a charity including a call for donations. Children could decide privately whether and how much they wanted to donate from money they had received earlier. Whole brain structural MRI scans were obtained to study associations between cortical thickness and donating behavior. In addition, resting state functional MRI scans were obtained to study whole brain functional connectivity and to examine functional connectivity between regions identified using structural MRI. In the lateral orbitofrontal cortex/pars orbitalis and pre-/postcentral cortex, a thicker cortex was associated with higher donations. Functional connectivity with these regions was not associated with donating behavior. These results suggest that donating behavior is not only situationally driven, but is also related brain morphology. The absence of functional connectivity correlates might imply that the associations with cortical thickness are involved in different underlying mechanisms of donating.

Sex Differences in the Relationship Between Conduct Disorder and Cortical Structure in Adolescents

OBJECTIVE

Previous studies have reported reduced cortical thickness and surface area and altered gyrification in frontal and temporal regions in adolescents with conduct disorder (CD). Although there is evidence that the clinical phenotype of CD differs between males and females, no studies have examined whether such sex differences extend to cortical and subcortical structure.

METHOD

As part of a European multisite study (FemNAT-CD), structural magnetic resonance imaging (MRI) data were collected from 48 female and 48 male participants with CD and from 104 sex-, age-, and pubertal-status-matched controls (14-18 years of age). Data were analyzed using surface-based morphometry, testing for effects of sex, diagnosis, and sex-by-diagnosis interactions, while controlling for age, IQ, scan site, and total gray matter volume.

RESULTS

CD was associated with cortical thinning and higher gyrification in ventromedial prefrontal cortex in both sexes. Males with CD showed lower, and females with CD showed higher, supramarginal gyrus cortical thickness compared with controls. Relative to controls, males with CD showed higher gyrification and surface area in superior frontal gyrus, whereas the opposite pattern was seen in females. There were no effects of diagnosis or sex-by-diagnosis interactions on subcortical volumes. Results are discussed with regard to attention-deficit/hyperactivity disorder, depression, and substance abuse comorbidity, medication use, handedness, and CD age of onset.

CONCLUSION

We found both similarities and differences between males and females in CD-cortical structure associations. This initial evidence that the pathophysiological basis of CD may be partly sex-specific highlights the need to consider sex in future neuroimaging studies and suggests that males and females may require different treatments.

Prefrontal mechanisms of comorbidity from a transdiagnostic and ontogenic perspective

Accumulating behavioral and genetic research suggests that most forms of psychopathology share common genetic and neural vulnerabilities and are manifestations of a relatively few core underlying processes. These findings support the view that comorbidity mostly arises, not from true co-occurrence of distinct disorders, but from the behavioral expression of shared vulnerability processes across the life span. The purpose of this review is to examine the role of the prefrontal cortex (PFC) in the shared vulnerability mechanisms underlying the clinical phenomena of comorbidity from a transdiagnostic and ontogenic perspective. In adopting this perspective, we suggest complex transactions between neurobiologically rooted vulnerabilities inherent in PFC circuitry and environmental factors (e.g., parenting, peers, stress, and substance use) across development converge on three key PFC-mediated processes: executive functioning, emotion regulation, and reward processing. We propose that individual differences and impairments in these PFC-mediated functions provide intermediate mechanisms for transdiagnostic symptoms and underlie behavioral tendencies that evoke and interact with environmental risk factors to further potentiate vulnerability.

Altered spontaneous brain activity in adolescent boys with pure conduct disorder revealed by regional homogeneity analysis

Functional magnetic resonance imaging (fMRI) studies have revealed abnormal neural activity in several brain regions of adolescents with conduct disorder (CD) performing various tasks. However, little is known about the spontaneous neural activity in people with CD in a resting state. The aims of this study were to investigate CD-associated regional activity abnormalities and to explore the relationship between behavioral impulsivity and regional activity abnormalities. Resting-state fMRI (rs-fMRI) scans were administered to 28 adolescents with CD and 28 age-, gender-, and IQ-matched healthy controls (HCs). The rs-fMRI data were subjected to regional homogeneity (ReHo) analysis. ReHo can demonstrate the temporal synchrony of regional blood oxygen level-dependent signals and reflect the coordination of local neuronal activity facilitating similar goals or representations. Compared to HCs, the CD group showed increased ReHo bilaterally in the insula as well as decreased ReHo in the right inferior parietal lobule, right middle temporal gyrus and right fusiform gyrus, left anterior cerebellum anterior, and right posterior cerebellum. In the CD group, mean ReHo values in the left and the right insula correlated positively with Barratt Impulsivity Scale (BIS) total scores. The results suggest that CD is associated with abnormal intrinsic brain activity, mainly in the cerebellum and temporal-parietal-limbic cortices, regions that are related to emotional and cognitive processing. BIS scores in adolescents with CD may reflect severity of abnormal neuronal synchronization in the insula.

Neural alterations in ADHD children as indicated by voxel-based cortical thickness and morphometry analysis

PURPOSE

Neuroimaging studies provide vital information related to the neurobiology of ADHD, but there still exists a wide gap in relevant information. The present study aimed to elucidate the neuroanatomical alteration in Attention deficit hyperactivity disorder (ADHD) children/adolescents.

METHODS

Voxel-based cortical thickness (VBCT) and voxel-based morphometry (VBM) was performed to examine neuroanatomic distinctions in 18 children/adolescents aged 7.5-13years diagnosed with DSM-IV TR as ADHD (non-medicated). They were compared with 18 healthy matched controls.

RESULTS

VBCT findings in ADHD children/adolescents revealed reduced cortical thickness in the left superior frontal, left orbito-frontal and left dorsal anterior cingulate cortex. VBM findings confirmed decreased gray matter volume in the left orbito frontal, left middle frontal/dorsolateral prefrontal, left middle temporal and left cerebellum in comparison to control group. A decrease in white matter volume was also observed in the left inferior frontal and left calcarine of ADHD children/adolescents.

CONCLUSION

Results reflect possible abnormal neuroanatomical development patterns in ADHD children.

Neural correlates of proactive and reactive aggression in adolescent twins

Verbal and physical aggression begin early in life and steadily decline thereafter in normal development. As a result, elevated aggressive behavior in adolescence may signal atypical development and greater vulnerability for negative mental and health outcomes. Converging evidence suggests that brain disturbances in regions involved in impulse control, emotional regulation, and sensation seeking may contribute to heightened aggression. However, little is known regarding the neural mechanisms underlying subtypes of aggression (i.e., proactive and reactive aggression) and whether they differ between males and females. Using a sample of 106 14-year-old adolescent twins, this study found that striatal enlargement was associated with both proactive and reactive aggression. We also found that volumetric alterations in several frontal regions including smaller middle frontal and larger orbitofrontal cortex were correlated with higher levels of aggression in adolescent twins. In addition, cortical thickness analysis showed that thickness alterations in many overlapping regions including middle frontal, superior frontal, and anterior cingulate cortex and temporal regions were associated with aggression in adolescent twins. Results support the involvement of fronto-limbic-striatal circuit in the etiology of aggression during adolescence. Aggr. Behav. 43:230-240, 2017. © 2016 Wiley Periodicals, Inc.

QEEG and LORETA in Teenagers With Conduct Disorder and Psychopathic Traits

BACKGROUND

Few studies have investigated the impact of the psychopathic traits on the EEG of teenagers with conduct disorder (CD). To date, there is no other research studying low-resolution brain electromagnetic tomography (LORETA) technique using quantitative EEG (QEEG) analysis in adolescents with CD and psychopathic traits.

OBJECTIVE

To find electrophysiological differences specifically related to the psychopathic traits. The current investigation compares the QEEG and the current source density measures between adolescents with CD and psychopathic traits and adolescents with CD without psychopathic traits.

METHODS

The resting EEG activity and LORETA for the EEG fast spectral bands were evaluated in 42 teenagers with CD, 25 with and 17 without psychopathic traits according to the Antisocial Process Screening Device. All adolescents were assessed using the DSM-IV-TR criteria. The EEG visual inspection characteristics and the use of frequency domain quantitative analysis techniques (narrow band spectral parameters) are described.

RESULTS

QEEG analysis showed a pattern of beta activity excess on the bilateral frontal-temporal regions and decreases of alpha band power on the left central-temporal and right frontal-central-temporal regions in the psychopathic traits group. Current source density calculated at 17.18 Hz showed an increase within fronto-temporo-striatal regions in the psychopathic relative to the nonpsychopathic traits group.

CONCLUSIONS

These findings indicate that QEEG analysis and techniques of source localization may reveal differences in brain electrical activity among teenagers with CD and psychopathic traits, which was not obvious to visual inspection. Taken together, these results suggest that abnormalities in a fronto-temporo-striatal network play a relevant role in the neurobiological basis of psychopathic behavior.

Grey Matter Volumes in Children with Conduct Problems and Varying Levels of Callous-Unemotional Traits

Genetic, behavioural and functional neuroimaging studies have revealed that different vulnerabilities characterise children with conduct problems and high levels of callous-unemotional traits (CP/HCU) compared with children with conduct problems and low callous-unemotional traits (CP/LCU). We used voxel-based morphometry to study grey matter volume (GMV) in 89 male participants (aged 10-16), 60 of whom exhibited CP. The CP group was subdivided into CP/HCU (n = 29) and CP/LCU (n = 31). Whole-brain and regional GMV were compared across groups (CP vs. typically developing (TD) controls (n = 29); and CP/HCU vs. CP/LCU vs. TD). Whole-brain analyses showed reduced GMV in left middle frontal gyrus in the CP/HCU group compared with TD controls. Region-of-interest analyses showed reduced volume in bilateral orbitofrontal cortex (OFC) in the CP group as a whole compared with TD controls. Reduced volume in left OFC was found to be driven by the CP/HCU group only, with significant reductions relative to both TD controls and the CP/LCU group, and no difference between these latter two groups. Within the CP group left OFC volume was significantly predicted by CU traits, but not conduct disorder symptoms. Reduced right anterior cingulate cortex volume was also found in CP/HCU compared with TD controls. Our results support previous findings indicating that GMV differences in brain regions central to decision-making and empathy are implicated in CP. However, they extend these data to suggest that some of these differences might specifically characterise the subgroup with CP/HCU, with GMV reduction in left OFC differentiating children with CP/HCU from those with CP/LCU.