Accelerated longitudinal cortical thinning in adolescence

Association of maternal hypertension during pregnancy with brain structure and behavioral problems in early adolescence

Emerging evidence suggests an association between maternal hypertension during pregnancy and mental health in the offspring. However, less is known about the role of hypertensive pregnancy in behavioral symptoms and brain structures of the offspring as well as in their developmental changes. Here, we utilized neuroimaging and behavioral data from 11,878 participants aged 9-10 years and their 2-year follow-up from the Adolescent Brain Cognitive Development (ABCD) study to investigate the long-term effects of maternal hypertension during pregnancy on early adolescent behavior and brain anatomy. Specifically, adolescents born of mothers with maternal hypertension are at risk of long-lasting behavioral problems, as manifested by higher externalizing and internalizing behavior scores at both 9-10 years and 11-12 years. These participants additionally presented with a higher cortical thickness, particularly in the fronto-parieto-temporal areas at 9-10 years. Four regions, including the left parahippocampus, left lateral orbitofrontal lobe, right superior temporal lobe and right temporal pole, remained thicker 2 years later. These findings were partially validated in rats modeled with Nω-nitro-L-arginine methyl ester (L-NAME) preeclampsia. Therefore, clinicians and women who experience hypertension during pregnancy should be warned of this risk, and healthcare providers should recommend appropriate clinical interventions for pregnancy-induced hypertension.

Alterations in cortical thickness and volumes of subcortical structures in pediatric patients with complete spinal cord injury

AIMS

To study the changes in cortical thickness and subcortical gray matter structures in children with complete spinal cord injury (CSCI), reveal the possible causes of dysfunction beyond sensory motor dysfunction after CSCI, and provide a possible neural basis for corresponding functional intervention training.

METHODS

Thirty-seven pediatric CSCI patients and 34 age-, gender-matched healthy children as healthy controls (HCs) were recruited. The 3D high-resolution T1-weighted structural images of all subjects were obtained using a 3.0 Tesla MRI system. Statistical differences between pediatric CSCI patients and HCs in cortical thickness and volumes of subcortical gray matter structures were evaluated. Then, correlation analyses were performed to analyze the correlation between the imaging indicators and clinical characteristics.

RESULTS

Compared with HCs, pediatric CSCI patients showed decreased cortical thickness in the right precentral gyrus, superior temporal gyrus, and posterior segment of the lateral sulcus, while increased cortical thickness in the right lingual gyrus and inferior occipital gyrus. The volume of the right thalamus in pediatric CSCI patients was significantly smaller than that in HCs. No significant correlation was found between the imaging indicators and the injury duration, sensory scores, and motor scores of pediatric CSCI patients.

CONCLUSIONS

These findings demonstrated that the brain structural reorganizations of pediatric CSCI occurred not only in sensory motor areas but also in cognitive and visual related brain regions, which may suggest that the visual processing, cognitive abnormalities, and related early intervention therapy also deserve greater attention beyond sensory motor rehabilitation training in pediatric CSCI patients.

Functional connectivity development along the sensorimotor-association axis enhances the cortical hierarchy

Human cortical maturation has been posited to be organized along the sensorimotor-association axis, a hierarchical axis of brain organization that spans from unimodal sensorimotor cortices to transmodal association cortices. Here, we investigate the hypothesis that the development of functional connectivity during childhood through adolescence conforms to the cortical hierarchy defined by the sensorimotor-association axis. We tested this pre-registered hypothesis in four large-scale, independent datasets (total n = 3355; ages 5-23 years): the Philadelphia Neurodevelopmental Cohort (n = 1207), Nathan Kline Institute-Rockland Sample (n = 397), Human Connectome Project: Development (n = 625), and Healthy Brain Network (n = 1126). Across datasets, the development of functional connectivity systematically varied along the sensorimotor-association axis. Connectivity in sensorimotor regions increased, whereas connectivity in association cortices declined, refining and reinforcing the cortical hierarchy. These consistent and generalizable results establish that the sensorimotor-association axis of cortical organization encodes the dominant pattern of functional connectivity development.

Learn from orientation prior for radiograph super-resolution: Orientation operator transformer

BACKGROUND AND OBJECTIVE

High-resolution radiographic images play a pivotal role in the early diagnosis and treatment of skeletal muscle-related diseases. It is promising to enhance image quality by introducing single-image super-resolution (SISR) model into the radiology image field. However, the conventional image pipeline, which can learn a mixed mapping between SR and denoising from the color space and inter-pixel patterns, poses a particular challenge for radiographic images with limited pattern features. To address this issue, this paper introduces a novel approach: Orientation Operator Transformer - O2former.

METHODS

We incorporate an orientation operator in the encoder to enhance sensitivity to denoising mapping and to integrate orientation prior. Furthermore, we propose a multi-scale feature fusion strategy to amalgamate features captured by different receptive fields with the directional prior, thereby providing a more effective latent representation for the decoder. Based on these innovative components, we propose a transformer-based SISR model, i.e., O2former, specifically designed for radiographic images.

RESULTS

The experimental results demonstrate that our method achieves the best or second-best performance in the objective metrics compared with the competitors at ×4 upsampling factor. For qualitative, more objective details are observed to be recovered.

CONCLUSIONS

In this study, we propose a novel framework called O2former for radiological image super-resolution tasks, which improves the reconstruction model's performance by introducing an orientation operator and multi-scale feature fusion strategy. Our approach is promising to further promote the radiographic image enhancement field.

The abnormal brain activation pattern of adolescents with major depressive disorder based on working memory tasks: A fNIRS study

OBJECTIVE

Although studies have confirmed that working memory (WM) is impaired among adults with major depressive disorder (MDD), generalizing these neurocognitive impairments to adolescents with MDD would be tenuous. Therefore, separate studies for adolescents with MDD are needed. Relatively little is known about the neural processes associated with WM dysfunction in adolescents with MDD. Thus, we examined whether adolescents with MDD have abnormal brain activation patterns compared to healthy controls (HC) during WM tasks and whether it was possible to distinguish adolescents with MDD and HC based on mean oxy-hemoglobin (Oxy-Hb) changes.

METHOD

A total of 87 adolescents with MDD and 63 HC were recruited. Functional near-infrared spectroscopy (fNIRS) was performed to monitor the concentrations of Oxy-Hb in the frontotemporal lobe while participants performed three WM tasks in order to examine WM impairments in adolescents with depression.

RESULTS

The mean changes in Oxy-Hb concentrations in the left prefrontal cortex and right prefrontal cortex were higher among HC than among patients during the encoding and maintenance phase under each WM-load task. Machine learning was used to distinguish adolescents with MDD and HC based on Oxy-Hb changes, with a moderate area under the curve of 0.84.

CONCLUSIONS

This study revealed WM defects in adolescents with MDD compared to HC based on mean Oxy-Hb changes, which can be valuable for distinguishing adolescents with MDD from HC.

A prospective 5-year longitudinal study detects neurocognitive and imaging correlates of seizure remission in self-limiting Rolandic epilepsy

OBJECTIVE

Self-limiting Rolandic epilepsy (RE) is the most common epilepsy in school-age children. Seizures are generally infrequent, but cognitive, language, and motor coordination problems can significantly impact the child's life. To better understand brain structure and function changes in RE, we longitudinally assessed neurocognition, cortical thickness, and subcortical volumes.

METHODS

At baseline, we recruited 30 participants diagnosed with RE and 24-healthy controls and followed up for 4.94 ± 0.8 years when the participants with RE were in seizure remission. Measures included were as follows: T1-weighted magnetic resonance brain imaging (MRI) with FreeSurfer analysis and detailed neuropsychological assessments. MRI and neuropsychological data were compared between baseline and follow-up in seizure remission.

RESULTS

Longitudinal MRI revealed excess cortical thinning in the left-orbitofrontal (p = 0.0001) and pre-central gyrus (p = 0.044). There is a significant association (p = 0.003) between a reduction in cortical thickness in the left-orbitofrontal cluster and improved processing of filtered words. Longitudinal neuropsychology revealed significant improvements in the symptoms of developmental coordination disorder (DCD, p = 0.005) in seizure remission.

CONCLUSIONS

There is evidence for altered development of neocortical regions between active seizure state and seizure remission in RE within two clusters maximal in the left-orbitofrontal and pre-central gyrus. There is significant evidence for improvement in motor coordination between active seizures and seizure remission and suggestive evidence for a decline in fluid intelligence and gains in auditory processing.

The Hitchhiker's guide to longitudinal models: A primer on model selection for repeated-measures methods

Longitudinal data are becoming increasingly available in developmental neuroimaging. To maximize the promise of this wealth of information on how biology, behavior, and cognition change over time, there is a need to incorporate broad and rigorous training in longitudinal methods into the repertoire of developmental neuroscientists. Fortunately, these models have an incredibly rich tradition in the broader developmental sciences that we can draw from. Here, we provide a primer on longitudinal models, written in a beginner-friendly (and slightly irreverent) manner, with a particular focus on selecting among different modeling frameworks (e.g., multilevel versus latent curve models) to build the theoretical model of development a researcher wishes to test. Our aims are three-fold: (1) lay out a heuristic framework for longitudinal model selection, (2) build a repository of references that ground each model in its tradition of methodological development and practical implementation with a focus on connecting researchers to resources outside traditional neuroimaging journals, and (3) provide practical resources in the form of a codebook companion demonstrating how to fit these models. These resources together aim to enhance training for the next generation of developmental neuroscientists by providing a solid foundation for future forays into advanced modeling applications.

Cortical thickness in the right medial frontal gyrus predicts planning performance in healthy children and adolescents

The ability to plan is an important part of the set of the cognitive skills called "executive functions." To be able to plan actions in advance is of great importance in everyday life and constitutes one of the major key features for academic as well as economic success. The present study aimed to investigate the neuroanatomical correlates of planning in normally developing children, as measured by the cortical thickness of the prefrontal cortex. Eighteen healthy children and adolescents underwent structural MRI examinations and the Tower of London (ToL) task. A multiple regression analysis revealed that the cortical thickness of the right caudal middle frontal gyrus (cMFG) was a significant predictor of planning performance. Neither the cortical thickness of any other prefrontal area nor gender were significantly associated with performance in the ToL task. The results of the present exploratory study suggest that the cortical thickness of the right, but not the left cMFG, is positively correlated with performance in the ToL task. We, therefore, conclude that increased cortical thickness may be more beneficial for higher-order processes, such as information integration, than for lower-order processes, such as the analysis of external information.

Association of retinal nerve layers thickness and brain imaging in healthy young subjects from the i-Share-Bordeaux study

Given the anatomical and functional similarities between the retina and the brain, the retina could be a "window" for viewing brain structures. We investigated the association between retinal nerve fiber layers (peripapillary retinal nerve fiber layer, ppRNFL; macular ganglion cell-inner plexiform layer, GC-IPL; and macular ganglion cell complex, GCC), and brain magnetic resonance imaging (MRI) parameters in young health adults. We included 857 students (mean age: 23.3 years, 71.3% women) from the i-Share study. We used multivariate linear models to study the cross-sectional association of each retinal nerve layer thickness assessed by spectral-domain optical coherence tomography (SD-OCT) with structural (volumes and cortical thickness), and microstructural brain markers, assessed on MRI globally and regionally. Microstructural MRI parameters included diffusion tensor imaging (DTI) and Neurite Orientation Dispersion and Density Imaging (NODDI). On global brain analysis, thicker ppRNFL, GC-IPL and GCC were all significantly associated with patterns of diffusion metrics consistent with higher WM microstructural integrity. In regional analyses, after multiple testing corrections, our results suggested significant associations of some retinal nerve layers with brain regional gray matter occipital volumes and with diffusion MRI parameters in a region involved in the visual pathway and in regions containing associative tracts. No associations were found with global volumes or with global or regional cortical thicknesses. Results of this study suggest that some retinal nerve layers may reflect brain structures. Further studies are needed to confirm these results in young subjects.

Longitudinal Gray Matter Trajectories in Pediatric Mild Traumatic Brain Injury

BACKGROUND AND OBJECTIVES

This prospective, longitudinal cohort study examined trajectories of brain gray matter macrostructure after pediatric mild traumatic brain injury (mTBI).

METHODS

Children aged 8-16.99 years with mTBI or mild orthopedic injury (OI) were recruited from 5 pediatric emergency departments. Reliable change between preinjury and 1 month postinjury symptom ratings was used to classify mTBI with or without persistent symptoms. Children completed postacute (2-33 days) and/or chronic (3 or 6 months) postinjury T1-weighted MRI, from which macrostructural metrics were derived using automated segmentation. Linear mixed-effects models were used, with multiple comparisons correction.

RESULTS

Groups (N = 623; 407 mTBI/216 OI; 59% male; age mean = 12.03, SD = 2.38 years) did not differ in total brain, white, or gray matter volumes or regional subcortical gray matter volumes. However, time postinjury, age at injury, and biological sex-moderated differences among symptom groups in cortical thickness of the angular gyrus, basal forebrain, calcarine cortex, gyrus rectus, medial and posterior orbital gyrus, and the subcallosal area all corrected p < 0.05. Gray matter macrostructural metrics did not differ between groups postacutely. However, cortical thinning emerged chronically after mTBI relative to OI in the angular gyrus in older children (d [95% confidence interval] = -0.61 [-1.15 to -0.08]); and in the basal forebrain (-0.47 [-0.94 to -0.01]), subcallosal area (-0.55 [-1.01 to -0.08]), and the posterior orbital gyrus (-0.55 [-1.02 to -0.08]) in females. Cortical thinning was demonstrated for frontal and occipital regions 3 months postinjury in males with mTBI with persistent symptoms vs without persistent symptoms (-0.80 [-1.55 to -0.05] to -0.83 [-1.56 to -0.10]) and 6 months postinjury in females and younger children with mTBI with persistent symptoms relative to mTBI without persistent symptoms and OI (-1.42 [-2.29 to -0.45] to -0.91 [-1.81 to -0.01]).

DISCUSSION

These findings signal little diagnostic and prognostic utility of postacute gray matter macrostructure in pediatric mTBI. However, mTBI altered the typical course of cortical gray matter thinning up to 6 months postinjury, even after symptoms typically abate in most children. Collapsing across symptom status obscured the neurobiological heterogeneity of discrete clinical outcomes after pediatric mTBI. The results illustrate the need to examine neurobiology in relation to clinical outcomes and within a neurodevelopmental framework.

Adolescent brain development in girls with Turner syndrome

Turner syndrome (TS) is a common sex chromosome aneuploidy in females associated with various physical, cognitive, and socio-emotional phenotypes. However, few studies have examined TS-associated alterations in the development of cortical gray matter volume and the two components that comprise this measure-surface area and thickness. Moreover, the longitudinal direct (i.e., genetic) and indirect (i.e., hormonal) effects of X-monosomy on the brain are unclear. Brain structure was assessed in 61 girls with TS (11.3 ± 2.8 years) and 55 typically developing girls (10.8 ± 2.3 years) for up to 4 timepoints. Surface-based analyses of cortical gray matter volume, thickness, and surface area were conducted to examine the direct effects of X-monosomy present before pubertal onset and indirect hormonal effects of estrogen deficiency/X-monosomy emerging after pubertal onset. Longitudinal analyses revealed that, whereas typically developing girls exhibited normative declines in gray matter structure during adolescence, this pattern was reduced or inverted in TS. Further, girls with TS demonstrated smaller total surface area and larger average cortical thickness overall. Regionally, the TS group exhibited decreased volume and surface area in the pericalcarine, postcentral, and parietal regions relative to typically developing girls, as well as larger volume in the caudate, amygdala, and temporal lobe regions and increased thickness in parietal and temporal regions. Surface area alterations were predominant by age 8, while maturational differences in thickness emerged by age 10 or later. Taken together, these results suggest the involvement of both direct and indirect effects of X-chromosome haploinsufficiency on brain development in TS.

Differential association of endothelial function with brain structure in youth with versus without bipolar disorder

BACKGROUND

Mood symptoms and disorders are associated with impaired endothelial function, a marker of early atherosclerosis. Given the increased vascular burden and neurostructural differences among individuals with mood disorders, we investigated the endothelial function and brain structure interface in relation to youth bipolar disorder (BD).

METHODS

This cross-sectional case-controlled study included 115 youth, ages 13-20 years (n = 66 BD; n = 49 controls [CG]). Cortical thickness and volume for regions of interest (ROI; insular cortex, ventrolateral prefrontal cortex [vlPFC], temporal lobe) were acquired from FreeSurfer processed T1-weighted MRI images. Endothelial function was assessed using pulse amplitude tonometry, yielding a reactive hyperemia index (RHI). ROI and vertex-wise analyses controlling for age, sex, obesity, and intracranial volume investigated for RHI-neurostructural associations, and RHI-by-diagnosis interactions.

RESULTS

In ROI analyses, higher RHI (i.e., better endothelial function) was associated with lower thickness in the insular cortex (β = -0.19, p_FDR = 0.03), vlPFC (β = -0.30, p_FDR = 0.003), and temporal lobe (β = -0.22, p_FDR = 0.01); and lower temporal lobe volume (β = -0.16, p_FDR = 0.01) in the overall sample. In vertex-wise analyses, higher RHI was associated with lower cortical thickness and volume in the insular cortex, prefrontal cortex (e.g., vlPFC), and temporal lobe. Additionally, higher RHI was associated with lower vlPFC and temporal lobe volume to a greater extent in youth with BD vs. CG.

CONCLUSIONS

Better endothelial function was associated with lower regional brain thickness and volume, contrasting the hypothesized associations. Additionally, we found evidence that this pattern was exaggerated in youth with BD. Future studies examining the direction of the observed associations and underlying mechanisms are warranted.

Neuroimaging profiling identifies distinct brain maturational subtypes of youth with mood and anxiety disorders

Mood and anxiety disorders typically begin in adolescence and have overlapping clinical features but marked inter-individual variation in clinical presentation. The use of multimodal neuroimaging data may offer novel insights into the underlying brain mechanisms. We applied Heterogeneity Through Discriminative Analysis (HYDRA) to measures of regional brain morphometry, neurite density, and intracortical myelination to identify subtypes of youth, aged 9-10 years, with mood and anxiety disorders (N = 1931) compared to typically developing youth (N = 2823). We identified three subtypes that were robust to permutation testing and sample composition. Subtype 1 evidenced a pattern of imbalanced cortical-subcortical maturation compared to the typically developing group, with subcortical regions lagging behind prefrontal cortical thinning and myelination and greater cortical surface expansion globally. Subtype 2 displayed a pattern of delayed cortical maturation indicated by higher cortical thickness and lower cortical surface area expansion and myelination compared to the typically developing group. Subtype 3 showed evidence of atypical brain maturation involving globally lower cortical thickness and surface coupled with higher myelination and neural density. Subtype 1 had superior cognitive function in contrast to the other two subtypes that underperformed compared to the typically developing group. Higher levels of parental psychopathology, family conflict, and social adversity were common to all subtypes, with subtype 3 having the highest burden of adverse exposures. These analyses comprehensively characterize pre-adolescent mood and anxiety disorders, the biopsychosocial context in which they arise, and lay the foundation for the examination of the longitudinal evolution of the subtypes identified as the study sample transitions through adolescence.

The Role of School Environment in Brain Structure, Connectivity, and Mental Health in Children: A Multimodal Investigation

BACKGROUND

Much work has been dedicated to understanding the effects of adverse home environments on brain development. While the school social and learning environment plays a role in child development, little work has been done to investigate the impact of the school environment on the developing brain. The goal of the present study was to examine associations between the school environment, brain structure and connectivity, and mental health.

METHODS

In this preregistered study we investigated these questions in a large sample of adolescents (9-10 years of age) from the Adolescent Brain Cognitive Development (ABCD) Study. We examined the association between school environment and gray matter (n = 10,435) and white matter (n = 10,770) structure and functional connectivity (n = 9528). We then investigated multivariate relationships between school-associated brain measures and mental health.

RESULTS

School environment was associated with connectivity of the auditory and retrosplenial temporal network as well as of higher-order cognitive networks like the cingulo-opercular, default mode, ventral attention, and frontoparietal networks. Multivariate analyses revealed that connectivity of the cingulo-opercular and default mode networks was also associated with mental health.

CONCLUSIONS

Findings shed light on the neural mechanisms through which favorable school environments may contribute to positive mental health outcomes in children. Our findings have implications for interventions targeted at promoting positive youth functioning through improving school environments.

Proportional intracranial volume correction differentially biases behavioral predictions across neuroanatomical features, sexes, and development

Individual differences in brain anatomy can be used to predict variations in cognitive ability. Most studies to date have focused on broad population-level trends, but the extent to which the observed predictive features are shared across sexes and age groups remains to be established. While it is standard practice to account for intracranial volume (ICV) using proportion correction in both regional and whole-brain morphometric analyses, in the context of brain-behavior predictions the possible differential impact of ICV correction on anatomical features and subgroups within the population has yet to be systematically investigated. In this work, we evaluate the effect of proportional ICV correction on sex-independent and sex-specific predictive models of individual cognitive abilities across multiple anatomical properties (surface area, gray matter volume, and cortical thickness) in healthy young adults (Human Connectome Project; n = 1013, 548 females) and typically developing children (Adolescent Brain Cognitive Development study; n = 1823, 979 females). We demonstrate that ICV correction generally reduces predictive accuracies derived from surface area and gray matter volume, while increasing predictive accuracies based on cortical thickness in both adults and children. Furthermore, the extent to which predictive models generalize across sexes and age groups depends on ICV correction: models based on surface area and gray matter volume are more generalizable without ICV correction, while models based on cortical thickness are more generalizable with ICV correction. Finally, the observed neuroanatomical features predictive of cognitive abilities are unique across age groups regardless of ICV correction, but whether they are shared or unique across sexes (within age groups) depends on ICV correction. These findings highlight the importance of considering individual differences in ICV, and show that proportional ICV correction does not remove the effects of cranial volume from anatomical measurements and can introduce ICV bias where previously there was none. ICV correction choices affect not just the strength of the relationships captured, but also the conclusions drawn regarding the neuroanatomical features that underlie those relationships.

Developmental trajectories of cortical thickness by functional brain network: The roles of pubertal timing and socioeconomic status

The human cerebral cortex undergoes considerable changes during development, with cortical maturation patterns reflecting regional heterogeneity that generally progresses in a posterior-to-anterior fashion. However, the organizing principles that govern cortical development remain unclear. In the current study, we characterized age-related differences in cortical thickness (CT) as a function of sex, pubertal timing, and two dissociable indices of socioeconomic status (i.e., income-to-needs and maternal education) in the context of functional brain network organization, using a cross-sectional sample (n = 789) diverse in race, ethnicity, and socioeconomic status from the Lifespan Human Connectome Project in Development (HCP-D). We found that CT generally followed a linear decline from 5 to 21 years of age, except for three functional networks that displayed nonlinear trajectories. We found no main effect of sex or age by sex interaction for any network. Earlier pubertal timing was associated with reduced mean CT and CT in seven networks. We also found a significant age by maternal education interaction for mean CT across cortex and CT in the dorsal attention network, where higher levels of maternal education were associated with steeper age-related decreases in CT. Taken together, our results suggest that these biological and environmental variations may impact the emerging functional connectome.

Longitudinal trajectories of cortical development in 22q11.2 copy number variants and typically developing controls

Probing naturally-occurring, reciprocal genomic copy number variations (CNVs) may help us understand mechanisms that underlie deviations from typical brain development. Cross-sectional studies have identified prominent reductions in cortical surface area (SA) and increased cortical thickness (CT) in 22q11.2 deletion carriers (22qDel), with the opposite pattern in duplication carriers (22qDup), but the longitudinal trajectories of these anomalies-and their relationship to clinical symptomatology-are unknown. Here, we examined neuroanatomic changes within a longitudinal cohort of 261 22q11.2 CNV carriers and demographically-matched typically developing (TD) controls (84 22qDel, 34 22qDup, and 143 TD; mean age 18.35, ±10.67 years; 50.47% female). A total of 431 magnetic resonance imaging scans (164 22qDel, 59 22qDup, and 208 TD control scans; mean interscan interval = 20.27 months) were examined. Longitudinal FreeSurfer analysis pipelines were used to parcellate the cortex and calculate average CT and SA for each region. First, general additive mixed models (GAMMs) were used to identify regions with between-group differences in developmental trajectories. Secondly, we investigated whether these trajectories were associated with clinical outcomes. Developmental trajectories of CT were more protracted in 22qDel relative to TD and 22qDup. 22qDup failed to show normative age-related SA decreases. 22qDel individuals with psychosis spectrum symptoms showed two distinct periods of altered CT trajectories relative to 22qDel without psychotic symptoms. In contrast, 22q11.2 CNV carriers with autism spectrum diagnoses showed early alterations in SA trajectories. Collectively, these results provide new insights into altered neurodevelopment in 22q11.2 CNV carriers, which may shed light on neural mechanisms underlying distinct clinical outcomes.

Associations between brain imaging and polygenic scores of mental health and educational attainment in children aged 9-11

Psychiatric disorders are highly heritable and polygenic, and many have their peak onset in late childhood and adolescence, a period of tremendous changes. Although the neurodevelopmental antecedents of mental illness are widely acknowledged, research in youth population cohorts is still scarce, preventing our progress towards the early characterization of these disorders. We included 7,124 children (9-11 years old) from the Adolescent Brain and Cognitive Development Study to map the associations of structural and diffusion brain imaging with common genetic variants and polygenic scores for psychiatric disorders and educational attainment. We used principal component analysis to derive imaging components, and calculated their heritability. We then assessed the relationship of imaging components with genetic and clinical psychiatric risk with univariate models and Canonical correlation analysis (CCA). Most imaging components had moderate heritability. Univariate models showed limited evidence and small associations of polygenic scores with brain structure at this age. CCA revealed two significant modes of covariation. The first mode linked higher polygenic scores for educational attainment with less externalizing problems and larger surface area. The second mode related higher polygenic scores for schizophrenia, bipolar disorder, and autism spectrum disorder to higher global cortical thickness, smaller white matter volumes of the fornix and cingulum, larger medial occipital surface area and smaller surface area of lateral and medial temporal regions. While cross-validation suggested limited generalizability, our results highlight the potential of multivariate models to better understand the transdiagnostic and distributed relationships between mental health and brain structure in late childhood.

Association of Maternal Tobacco Use During Pregnancy With Preadolescent Brain Morphology Among Offspring

IMPORTANCE

Maternal tobacco use during pregnancy has been associated with various health consequences, including suboptimal neurodevelopment in offspring. However, the effect of prenatal exposure to maternal smoking on child brain development has yet to be elucidated.

OBJECTIVE

To investigate the association between maternal smoking during pregnancy and offspring brain development in preadolescence as well as the mediating pathways.

DESIGN, SETTING, AND PARTICIPANTS

This prospective, population-based cohort study was embedded in the Generation R Study, Rotterdam, the Netherlands. The Generation R Study was launched in 2002, with follow-up ongoing. Child brain morphology was assessed at 9 to 11 years of age (ie, 10-12 years between exposure and outcome assessment). Data analysis was performed from March 1, 2021, to February 28, 2022, and at the time of manuscript revision. Participants included the singleton children of pregnant women residing in the study area with an expected date of delivery between April 1, 2002, and January 31, 2006; 2704 children with information on maternal smoking during pregnancy and structural neuroimaging at 9 to 11 years of age were included. A subsample of 784 children with data on DNA methylation at birth was examined in the mediation analysis.

EXPOSURES

Information on maternal smoking during pregnancy was collected via a questionnaire in each trimester. As a contrast, paternal smoking was assessed at recruitment.

MAIN OUTCOMES AND MEASURES

Brain morphology, including brain volumes and surface-based cortical measures (thickness, surface area, and gyrification), was assessed with magnetic resonance imaging. For mediation analysis, DNA methylation at birth was quantified by a weighted methylation risk score.

RESULTS

The 2704 participating children (1370 [50.7%] girls and 1334 [49.3%] boys) underwent brain imaging assessment at a mean (SD) age of 10.1 (0.6) years. Compared with nonexposed children (n = 2102), exposure to continued maternal smoking during pregnancy (n = 364) was associated with smaller total brain volume (volumetric difference [b] = -14.5 [95% CI, -25.1 to -4.0] cm3), cerebral gray matter volume (b = -7.8 [95% CI, -13.4 to -2.3] cm3), cerebral white matter volume (b = -5.9 [95% CI, -10.7 to -1.0] cm3), and surface area and less gyrification. These associations were not explained by paternal smoking nor mediated by smoking-associated DNA methylation patterns at birth. Children exposed to maternal smoking only in the first trimester (n = 238) showed no differences in brain morphology compared with nonexposed children.

CONCLUSIONS AND RELEVANCE

The findings of this cohort study suggest that continued maternal tobacco use during pregnancy was associated with lower brain volumes and suboptimal cortical traits of offspring in preadolescence, which seemed to be independent of shared family factors. Tobacco cessation before pregnancy, or as soon as pregnancy is known, should be recommended to women for optimal brain development of their offspring.

Helmet Technology, Head Impact Exposure, and Cortical Thinning Following a Season of High School Football

The purpose of this study was to compare the effects of wearing older, lower-ranked football helmets (LRank) to wearing newer, higher-ranked football helmets (HRank) on pre- to post-season changes in cortical thickness in response to repetitive head impacts and assess whether changes in cortical thickness are associated with head impact exposure for either helmet type. 105 male high-school athletes (N_HRank = 52, N_LRank = 53) wore accelerometers affixed behind the left mastoid during all practices and games for one regular season of American football to monitor head impact exposure. Pre- and post-season magnetic resonance imaging (MRI) were completed to assess longitudinal changes in cortical thickness. Significant reductions in cortical thickness (i.e., cortical thinning) were observed pre- to post-season for each group, but these longitudinal alterations were not significantly different between the LRank and HRank groups. Further, significant group-by-head impact exposure interactions were observed when predicting changes in cortical thickness. Specifically, a greater frequency of high magnitude head impacts during the football season resulted in greater cortical thinning for the LRank group, but not for the HRank group. These data provide preliminary in vivo evidence that HRank helmets may provide a buffer between the specific effect of high magnitude head impacts on regional thinning by dissipating forces more evenly throughout the cortex. However, future research with larger sample sizes, increased longitudinal measures and additional helmet technologies is warranted to both expand upon and further validate the present study findings.

Bayesian causal network modeling suggests adolescent cannabis use accelerates prefrontal cortical thinning

While there is substantial evidence that cannabis use is associated with differences in human brain development, most of this evidence is correlational in nature. Bayesian causal network (BCN) modeling attempts to identify probable causal relationships in correlational data using conditional probabilities to estimate directional associations between a set of interrelated variables. In this study, we employed BCN modeling in 637 adolescents from the IMAGEN study who were cannabis naïve at age 14 to provide evidence that the accelerated prefrontal cortical thinning found previously in adolescent cannabis users by Albaugh et al. [1] is a result of cannabis use causally affecting neurodevelopment. BCNs incorporated data on cannabis use, prefrontal cortical thickness, and other factors related to both brain development and cannabis use, including demographics, psychopathology, childhood adversity, and other substance use. All BCN algorithms strongly suggested a directional relationship from adolescent cannabis use to accelerated cortical thinning. While BCN modeling alone does not prove a causal relationship, these results are consistent with a body of animal and human research suggesting that adolescent cannabis use adversely affects brain development.

Investigating default mode network connectivity disruption in children of mothers with depression

BACKGROUND

Exposure to maternal major depressive disorder (MDD) bears long-term negative consequences for children's well-being; to date, no research has examined how exposure at different stages of development differentially affects brain functioning.

AIMS

Utilising a unique cohort followed from birth to preadolescence, we examined the effects of early versus later maternal MDD on default mode network (DMN) connectivity.

METHOD

Maternal depression was assessed at birth and ages 6 months, 9 months, 6 years and 10 years, to form three groups: children of mothers with consistent depression from birth to 6 years of age, which resolved by 10 years of age; children of mothers without depression; and children of mothers who were diagnosed with MDD in late childhood. In preadolescence, we used magnetoencephalography and focused on theta rhythms, which characterise the developing brain.

RESULTS

Maternal MDD was associated with disrupted DMN connectivity in an exposure-specific manner. Early maternal MDD decreased child connectivity, presenting a profile typical of early trauma or chronic adversity. In contrast, later maternal MDD was linked with tighter connectivity, a pattern characteristic of adult depression. Aberrant DMN connectivity was predicted by intrusive mothering in infancy and lower mother-child reciprocity and child empathy in late childhood, highlighting the role of deficient caregiving and compromised socio-emotional competencies in DMN dysfunction.

CONCLUSIONS

The findings pinpoint the distinct effects of early versus later maternal MDD on the DMN, a core network sustaining self-related processes. Results emphasise that research on the influence of early adversity on the developing brain should consider the developmental stage in which the adversity occured.

Association of blood pressure with brain structure in youth with and without bipolar disorder

BACKGROUND

We previously found that blood pressure (BP) is elevated, and associated with poorer neurocognition, in youth with bipolar disorder (BD). While higher BP is associated with smaller brain structure in adults, studies have not examined this topic in BD or youth.

METHODS

Participants were 154 youth, ages 13-20 (n = 81 BD, n = 73 HC). Structural magnetic resonance imaging and diastolic (DBP), and systolic (SBP) pressure were obtained. Region of interest (ROI; anterior cingulate cortex [ACC], insular cortex, hippocampus) and vertex-wise analyses controlling for age, sex, body-mass-index, and intracranial volume investigated BP-neurostructural associations; a group-by-BP interaction was also assessed.

RESULTS

In ROI analyses, higher DBP in the overall sample was associated with smaller insular cortex area (β=-0.18 p = 0.007) and was associated with smaller ACC area to a significantly greater extent in HC vs. BD (β=-0.14 p = 0.015). In vertex-wise analyses, higher DBP and SBP were associated with smaller area and volume in the insular cortex, frontal, parietal, and temporal regions in the overall sample. Additionally, higher SBP was associated with greater thickness in temporal and parietal regions. Finally, higher SBP was associated with smaller area and volume in frontal, parietal, and temporal regions to a significantly greater extent in BD vs. HC.

LIMITATIONS

Cross-sectional design, single assessment of BP.

CONCLUSION

BP is associated with brain structure in youth, with variability related to structural phenotype (volume vs. thickness) and psychiatric diagnosis (BD vs. HC). Future studies evaluating temporality of these findings, and the association of BP changes on brain structure in youth, are warranted.

Correlations between facial emotion processing and biochemical abnormalities in untreated adolescent patients with major depressive disorder: A proton magnetic resonance spectroscopy study

BACKGROUND

Studies show that disturbances of the fronto-striato-thalamic-cerebellar circuit could be correlated to facial emotion processing (FEP) biases in major depressive disorder (MDD). Nevertheless, the underlying mechanism of natural metabolism-emotion relationships in adolescent MDD remains unclear.

METHODS

Thirty-seven adolescent patients with MDD and 30 healthy controls completed FEP tasks using the Chinese Facial Affective Picture System (CAFPS). Proton magnetic resonance spectroscopy (¹H-MRS) was also used to obtain ratios of N-acetylaspartate (NAA) /creatine (Cr) and choline (Cho) /Cr ratios in the prefrontal cortex (PFC), anterior cingulate cortex (ACC), putamen, thalamus and cerebellum. Correlations between abnormal neurometabolic ratios and FEP were also computed.

RESULTS

Compared with the control group, the MDD group had significantly lower accuracy and perception intensity of happiness, and significantly higher accuracy of disgust and perception intensity of sad and fearful faces in FEP tasks. Compared to healthy controls, adolescent patients with MDD showed significantly lower NAA/Cr ratios in the left PFC, higher NAA/Cr ratios in the right thalamus, and higher Cho/Cr ratios in the right putamen, although there were no significant differences in metabolites in the ACC and cerebellum between two groups. In the MDD group, NAA/Cr ratios of the right thalamus were negatively correlated with happy reaction time and positively correlated with sad, anger, and fear intensity; Cho/Cr ratios in the right putamen were positively correlated with fear reaction time.

CONCLUSIONS

Our findings suggest that FEP bias may exist in adolescents with MDD, while the impairment of FEP may be associated with abnormal metabolites in the fronto-striato-thalamic circuit.

You Only Get One Brain: Adult Reflections on the Long-Term Impacts of Traumatic Brain Injury in Adolescence

Background:

This research adds to scarce literature regarding adolescent experiences of traumatic brain injury (TBI). Retrospective accounts of young adults who had sustained a TBI in adolescence were analysed to explore the perceived impact this had on their lives and forming identities during this important developmental stage.

Methods:

Thirteen adults (aged 20–25 years; mean 23 years) who sustained a mild or moderate TBI during adolescence (i.e. aged 13–17 years at injury), approximately 7.7 years (range = 6.7–8.0 years) prior, participated in the research. Semi-structured individual interviews, analysed using thematic analysis, explored participants’ experiences following their TBIs.

Results:

Thematic analysis of interview data produced two categories of themes: (1) Impacts on Important Areas of Life, which included: schoolwork suffered, career opportunities became limited, struggling with work and missing out socially; and (2) Impacts on Identity: with themes including feeling ‘stupid’, feeling self-conscious, loss of social identity and being dependent.

Conclusions:

TBI sustained during adolescence can have broad impacts on important areas of life and on developing identity.

Neurodevelopment of the association cortices: Patterns, mechanisms, and implications for psychopathology

The human brain undergoes a prolonged period of cortical development that spans multiple decades. During childhood and adolescence, cortical development progresses from lower-order, primary and unimodal cortices with sensory and motor functions to higher-order, transmodal association cortices subserving executive, socioemotional, and mentalizing functions. The spatiotemporal patterning of cortical maturation thus proceeds in a hierarchical manner, conforming to an evolutionarily rooted, sensorimotor-to-association axis of cortical organization. This developmental program has been characterized by data derived from multimodal human neuroimaging and is linked to the hierarchical unfolding of plasticity-related neurobiological events. Critically, this developmental program serves to enhance feature variation between lower-order and higher-order regions, thus endowing the brain's association cortices with unique functional properties. However, accumulating evidence suggests that protracted plasticity within late-maturing association cortices, which represents a defining feature of the human developmental program, also confers risk for diverse developmental psychopathologies.

Cortical Thinning and Sleep Slow Wave Activity Reductions Mediate Age-Related Improvements in Cognition During Mid-Late Adolescence

Study Objectives

Gains in cognitive test performance that occur during adolescence are associated with brain maturation. Cortical thinning and reduced sleep slow wave activity (SWA) are markers of such developmental changes. Here we investigate whether they mediate age-related improvements in cognition.

Methods

109 adolescents aged 15–19 years (49 males) underwent magnetic resonance imaging, polysomnography (PSG), and a battery of cognitive tasks within a 2-month time window. Cognitive tasks assessed nonverbal intelligence, sustained attention, speed of processing and working memory and executive function. To minimize the effect of sleep history on SWA and cognitive performance, PSG and test batteries were administered only after at least 8 nights of 9-h time-in-bed (TIB) sleep opportunity.

Results

Age-related improvements in speed of processing (r = 0.33, p = 0.001) and nonverbal intelligence (r = 0.24, p = 0.01) domains were observed. These cognitive changes were associated with reduced cortical thickness, particularly in bilateral temporoparietal regions (rs = −0.21 to −0.45, ps < 0.05), as well as SWA (r = −0.35, p < 0.001). Serial mediation models found that ROIs in the middle/superior temporal cortices, together with SWA mediated the age-related improvement observed on cognition.

Conclusions

During adolescence, age-related improvements in cognition are mediated by reductions in cortical thickness and sleep SWA.

Internalising and externalising in early adolescence predict later executive function, not the other way around: a cross-lagged panel analysis

Developmental changes in the brain networks involved in emotion regulation are thought to contribute to vulnerability to mental health problems during adolescence. Executive control is often viewed as allowing top-down regulation of emotional responses. However, while associations between executive control and mental health are commonly observed in both clinical and non-clinical populations, the direction of these associations remains unclear. Low, or immature, cognitive control could limit emotion regulation. Reversely, high emotionality could impede cognitive functioning. The scarcity of longitudinal studies testing for bi-directional effects, particularly in adolescence, has made it difficult to draw conclusions. This study analysed data from 1,445 participants of a longitudinal cohort in a cross-lagged panel design to understand bi-directional longitudinal associations between executive function and emotional behaviours across adolescence. Executive function was assessed using experimental working memory and inhibitory control tasks, emotional behaviours through parental report of internalising and externalising behaviours. Cross-sectional associations were replicated. Controlling for cross-sectional associations, early executive functions were not found to predict later emotional behaviours. Instead, early emotional behaviours predicted later executive function, with the strongest link observed between early externalising and later working memory. These results suggest that emotional well-being may affect the maturation of executive function during adolescence.

Maturational trajectories of pericortical contrast in typical brain development

In the last few years, a significant amount of work has aimed to characterize maturational trajectories of cortical development. The role of pericortical microstructure putatively characterized as the gray-white matter contrast (GWC) at the pericortical gray-white matter boundary and its relationship to more traditional morphological measures of cortical morphometry has emerged as a means to examine finer grained neuroanatomical underpinnings of cortical changes. In this work, we characterize the GWC developmental trajectories in a representative sample (n = 394) of children and adolescents (~4 to ~22 years of age), with repeated scans (1-3 scans per subject, total scans n = 819). We tested whether linear, quadratic, or cubic trajectories of contrast development best described changes in GWC. A best-fit model was identified vertex-wise across the whole cortex via the Akaike Information Criterion (AIC). GWC across nearly the whole brain was found to significantly change with age. Cubic trajectories were likeliest for 63% of vertices, quadratic trajectories were likeliest for 20% of vertices, and linear trajectories were likeliest for 16% of vertices. A main effect of sex was observed in some regions, where males had a higher GWC than females. However, no sex by age interactions were found on GWC. In summary, our results suggest a progressive decrease in GWC at the pericortical boundary throughout childhood and adolescence. This work contributes to efforts seeking to characterize typical, healthy brain development and, by extension, can help elucidate aberrant developmental trajectories.

Morphological and Age-Related Changes in the Narcolepsy Brain

Morphological changes in the cortex of narcolepsy patients were investigated by surface-based morphometry analysis in this study. Fifty-one type 1 narcolepsy patients and 60 demographically group-matched healthy controls provided resting-state functional and high-resolution 3T anatomical magnetic resonance imaging scans. Vertex-level cortical thickness (CT), gyrification, and voxel-wise functional connectivity were calculated. Adolescent narcolepsy patients showed decreased CT in bilateral frontal cortex and left precuneus. Adolescent narcolepsy demonstrated increased gyrification in left occipital lobe, left precuneus, and right fusiform but decreased gyrification in left postcentral gyrus, whereas adult narcolepsy exhibited increased gyrification in left temporal lobe and right frontal cortex. Furthermore, sleepiness severity was associated with altered CT and gyrification. Increased gyrification was associated with reduced long-range functional connectivity. In adolescent patients, those with more severe sleepiness showed increased right postcentral gyrification. Decreased frontal and occipital gyrification was found in cases with hallucination. In adult patients, a wide range of regions showed reduced gyrification in those with adolescence-onset compared adult-onset narcolepsy patients. Particularly the frontal lobes showed altered brain morphology, being a thinner cortex and more gyri. The impact of narcolepsy on age-related brain morphological changes may remain from adolescence to young adulthood, and it was especially exacerbated in adolescence.

Brain structure associations with phonemic and semantic fluency in typically-developing children

Verbal fluency is the ability to retrieve lexical knowledge quickly and efficiently and develops during childhood and adolescence. Few studies have investigated associations between verbal fluency performance and brain structural variation in children. Here we examined associations of verbal fluency performance with structural measures of frontal and temporal language-related brain regions and their connections in 73 typically-developing children aged 7-13 years. Tract-based spatial statistics was used to extract fractional anisotropy (FA) from the superior longitudinal fasciculus/arcuate fasciculus (SLF/AF), and the white matter underlying frontal and temporal language-related regions. FreeSurfer was used to extract cortical thickness and surface area. Better semantic and phonemic fluency performance was associated with higher right SLF/AF FA, and phonemic fluency was also modestly associated with lower left SLF/AF FA. Explorative voxelwise analyses for semantic fluency suggested associations with FA in other fiber tracts, including corpus callosum and right inferior fronto-occipital fasciculus. Overall, our results suggest that verbal fluency performance in children may rely on right hemisphere structures, possibly involving both language and executive function networks, and less on solely left hemisphere structures as often is observed in adults. Longitudinal studies are needed to clarify whether these associations are mediated by maturational processes, stable characteristics and/or experience.

New insights into the dynamic development of the cerebral cortex in childhood and adolescence: Integrating macro- and microstructural MRI findings

Through dynamic transactional processes between genetic and environmental factors, childhood and adolescence involve reorganization and optimization of the cerebral cortex. The cortex and its development plays a crucial role for prototypical human cognitive abilities. At the same time, many common mental disorders appear during these critical phases of neurodevelopment. Magnetic resonance imaging (MRI) can indirectly capture several multifaceted changes of cortical macro- and microstructure, of high relevance to further our understanding of the neural foundation of cognition and mental health. Great progress has been made recently in mapping the typical development of cortical morphology. Moreover, newer less explored MRI signal intensity and specialized quantitative T2 measures have been applied to assess microstructural cortical development. We review recent findings of typical postnatal macro- and microstructural development of the cerebral cortex from early childhood to young adulthood. We cover studies of cortical volume, thickness, area, gyrification, T1-weighted (T1w) tissue contrasts such a grey/white matter contrast, T1w/T2w ratio, magnetization transfer and myelin water fraction. Finally, we integrate imaging studies with cortical gene expression findings to further our understanding of the underlying neurobiology of the developmental changes, bridging the gap between ex vivo histological- and in vivo MRI studies.

Elevated lipids are associated with reduced regional brain structure in youth with bipolar disorder

OBJECTIVE

Abnormal blood lipid levels are common in bipolar disorder (BD) and correlate with mood symptoms and neurocognition. However, studies have not examined the lipid-brain structure association in BD or youth.

METHODS

This study examined low-density lipoprotein (LDL-C), high-density lipoprotein (HDL-C), triglycerides, and total cholesterol (TC) levels in relation to brain structure utilizing T1-weighted images, among participants ages 13-20 with BD (n = 55) and healthy controls (HC; n = 47). General linear models investigated group differences in the association of lipids with anterior cingulate cortex (ACC), hippocampus, and inferior parietal lobe structure, controlling for age, sex, body mass index, and intracranial volume. For significant associations, post hoc within-group analyses were undertaken. Exploratory vertex-wise analyses further investigated group differences in the lipid-brain structure association.

RESULTS

There were significant group differences in the association of LDL-C (β = -0.29 p = 0.001), and TC (β = -0.21 p = 0.016), with hippocampal volume, and triglycerides with ACC volume (β = -0.25 p = 0.01) and area (β = -0.26 p = 0.004). Elevated lipids were associated with smaller brain structure to a significantly greater extent in BD vs HC. Post hoc analyses revealed that elevated LDL-C (β = -0.27 p = 0.007) and reduced HDL-C (β = 0.24 p = 0.01) were associated with smaller hippocampal volume in the BD group. Exclusion of BD second-generation antipsychotic users did not alter these results. Vertex-wise analyses further showed that elevated lipids were associated with smaller brain structure to a significantly greater extent in BD vs HC, across the cortex.

CONCLUSION

Elevated lipids are associated with smaller brain structure in BD. Research evaluating lipid-brain structure associations prospectively and whether lipid optimization has salutary effects on brain structure is necessary.

Neural correlates of implicit agency during the transition from adolescence to adulthood: An ERP study

Sense of agency (SoA), the experience of being in control of our voluntary actions and their outcomes, is a key feature of normal human experience. Frontoparietal brain circuits associated with SoA undergo a major maturational process during adolescence. To examine whether this translates to neurodevelopmental changes in agency experience, we investigated two key neural processes associated with SoA, the activity that is leading to voluntary action (Readiness Potential) and the activity that is associated with the action outcome processing (attenuation of auditory N1 and P2 event related potentials, ERPs) in mid-adolescents (13-14), late-adolescents (18-20) and adults (25-28) while they perform an intentional binding task. In this task, participants pressed a button (action) that delivered a tone (outcome) after a small delay and reported the time of the tone using the Libet clock. This action-outcome condition alternated with a no-action condition where an identical tone was triggered by a computer. Mid-adolescents showed greater outcome binding, such that they perceived self-triggered tones as being temporally closer to their actions compared to adults. Suggesting greater agency experience over the outcomes of their voluntary actions during mid-adolescence. Consistent with this, greater levels of attenuated neural response to self-triggered auditory tones (specifically P2 attenuation) were found during mid-adolescence compared to older age groups. This enhanced attenuation decreased with age as observed in outcome binding. However, there were no age-related differences in the readiness potential leading to the voluntary action (button press) as well as in the N1 attenuation to the self-triggered tones. Notably, in mid-adolescents greater outcome binding scores were positively associated with greater P2 attenuation, and smaller negativity in the late readiness potential. These findings suggest that the greater experience of implicit agency observed during mid-adolescence may be mediated by a neural over-suppression of action outcomes (auditory P2 attenuation), and over-reliance on motor preparation (late readiness potential), which we found to become adult-like during late-adolescence. Implications for adolescent development and SoA related neurodevelopmental disorders are discussed.

Fine particulate matter exposure during childhood relates to hemispheric-specific differences in brain structure

BACKGROUND

Emerging findings have increased concern that exposure to fine particulate matter air pollution (aerodynamic diameter ≤ 2.5 μm; PM2.5) may be neurotoxic, even at lower levels of exposure. Yet, additional studies are needed to determine if exposure to current PM2.5 levels may be linked to hemispheric and regional patterns of brain development in children across the United States.

OBJECTIVES

We examined the cross-sectional associations between geocoded measures of concurrent annual average outdoor PM2.5 exposure, regional- and hemisphere-specific differences in brain morphometry and cognition in 10,343 9- and 10- year-old children.

METHODS

High-resolution structural T1-weighted brain magnetic resonance imaging (MRI) and NIH Toolbox measures of cognition were collected from children at ages 9-10 years. FreeSurfer was used to quantify cortical surface area, cortical thickness, as well as subcortical and cerebellum volumes in each hemisphere. PM2.5 concentrations were estimated using an ensemble-based model approach and assigned to each child's primary residential address collected at the study visit. We used mixed-effects models to examine regional- and hemispheric- effects of PM2.5 exposure on brain estimates and cognition after considering nesting of participants by familial relationships and study site, adjustment for socio-demographic factors and multiple comparisons.

RESULTS

Annual residential PM2.5 exposure (7.63 ± 1.57 µg/m3) was associated with hemispheric specific differences in gray matter across cortical regions of the frontal, parietal, temporal and occipital lobes as well as subcortical and cerebellum brain regions. There were hemispheric-specific associations between PM2.5 exposures and cortical surface area in 9/31 regions; cortical thickness in 22/27 regions; and volumes of the thalamus, pallidum, and nucleus accumbens. We found neither significant associations between PM2.5 and task performance on individual measures of neurocognition nor evidence that sex moderated the observed associations.

DISCUSSION

Even at relatively low-levels, current PM2.5 exposure across the U.S. may be an important environmental factor influencing patterns of structural brain development in childhood. Prospective follow-up of this cohort will help determine how current levels of PM2.5 exposure may affect brain development and subsequent risk for cognitive and emotional problems across adolescence.

The moderating role of socioeconomic status on level of responsibility, executive functioning, and cortical thinning during adolescence

Brain development is exquisitely sensitive to psychosocial experiences, with implications for neurodevelopmental trajectories, for better or worse. The premise of this investigation was that the level of responsibility in adolescence may relate to brain structure and higher-order cognitive functions. In a sample of 108 adolescents, we focused on cortical thickness (using FreeSurfer) as an indicator of neurodevelopment in regions previously implicated in executive functioning (EF) and examined performance on an EF task outside of the scanner, in the context of level of responsibility. We further investigated whether socioeconomic status (SES) and family stress moderated the relationship between responsibility and brain structure or EF. Findings revealed that greater responsibility was related to thinner left precuneus and right middle frontal cortex. In lower SES adolescents, greater responsibility predicted thinner left precuneus and right middle frontal cortex, which have been consistently implicated in EF. Higher SES adolescents did not show structural differences related to responsibility, however, they did exhibit better EF performance. It may be that circumstances surrounding the need for greater responsibility in lower SES households are detrimental to neurodevelopment compared to higher SES households. Alternatively, responsibility may act as a protective factor that bolsters cortical thinning in regions related to EF.

Modeling Individual Differences in Brain Development

Within the field of developmental cognitive neuroscience, there is an increasing interest in studying individual differences in human brain development in order to predict mental health outcomes. So far, however, most longitudinal neuroimaging studies focus on group-level estimates. In this review, we highlight longitudinal neuroimaging studies that have moved beyond group-level estimates to illustrate the heterogeneity in patterns of brain development. We provide practical methodological recommendations on how longitudinal neuroimaging datasets can be used to understand heterogeneity in human brain development. Finally, we address how taking an individual-differences approach in developmental neuroimaging studies could advance our understanding of why some individuals develop mental health disorders.

Reduced Thalamus Volume and Enhanced Thalamus and Fronto-Parietal Network Integration in the Chess Experts

The ability of chess experts depends to a large extent on spatial visual processing, attention, and working memory, all of which are thought to be mediated by the thalamus. This study explored whether continued practice and rehearsal over a long period of time results in structural changes in the thalamic region. We found smaller gray matter volume regions in the thalami of expert Chinese chess players in comparison with novice players. We then used these regions as seeds for resting-state functional connectivity analysis and observed significantly strengthened integration between the thalamus and fronto-parietal network in expert Chinese chess players. This strengthened integration that includes a group of brain regions showing an increase in activation to external stimulation, particularly during tasks relying on working memory and attention. Our findings demonstrate structural changes in the thalamus caused by a wide range of engagement in chess problem solving, and that this strengthened functional integration with widely distributed circuitry better supports high-level cognitive control of behavior.

Post-Acute Cortical Thickness in Children with Mild Traumatic Brain Injury versus Orthopedic Injury

Studies of brain morphometry may illuminate the effects of pediatric mild traumatic brain injury (TBI; e.g., concussion). However, no published studies have examined cortical thickness in the early injury phases of pediatric mild TBI using an appropriate comparison group. The current study used an automated approach (i.e., FreeSurfer) to determine whether cortical thickness differed in children following a mild TBI or a mild orthopedic injury (OI), and to examine whether post-acute cortical thickness predicted post-acute and chronic post-concussive symptoms (PCS). Children ages 8.00-16.99 years with mild TBI (n = 136) or OI (n = 70) were recruited at emergency department visits to two children's hospitals, during which parents rated children's pre-injury symptoms retrospectively. Children completed a post-acute (3-24 days post-injury) assessment, which included a 3 Tesla MRI, and 3- and 6-month post-injury assessments. Parents and children rated PCS at each assessment. Cortical thickness was estimated using FreeSurfer. Linear mixed effects and multi-variable negative binomial regression models were used to test study aims, with false discovery rate (FDR) correction for multiple comparisons. Groups differed significantly on left parietal cortical thickness (TBI > OI) after FDR correction. Cortical thickness also varied by brain subregion and age, but not sex. Groups differed significantly on PCS post-acutely (TBI > OI), but not at 3 or 6 months. Right frontal thickness was positively related to post-acute PCS in both groups. Right cingulum thickness predicted chronic PCS in the OI group only. Results highlight the complexity of predicting outcomes of pediatric mild TBI from post-acute neuroimaging biomarkers.

Individual Variables Involved in Perceived Pressure for Adolescent Drinking

Adolescence is a stage when individuals are especially vulnerable to the influence of their peer group, which could lead to the development of problematic behavior, such as drinking alcohol, due to perceived pressure. The objective of this study was to analyze the role of self-esteem, impulsivity, anxiety sensitivity and expectations for use under perceived pressure to drink alcohol among young people.

METHODS

The sample was made up of 1287 high school students aged 14 to 18, with a mean age of 15.11. The Bayes factor and mediation models were estimated to evaluate the data.

RESULTS

The results showed the existence of a positive relationship of impulsivity, anxiety sensitivity and expectations for use with perceived pressure. However, this relationship was negative with self-esteem and perception of pressure to drink alcohol. Furthermore, the model results showed that self-esteem mediates the relationship between physical, cognitive and social anxiety sensitivity and positive expectations with perceived pressure to drink alcohol in adolescence.

CONCLUSIONS

Given the strong need for affiliation during youth, it is hard to control grouping and peer influence on drinking behavior. However, knowledge of the role of individual variables, such as those described here, in perceived pressure could improve the prevention and intervention of such behaviors.

Altered cortical structure and psychiatric symptom risk in adolescents exposed to maternal stress in utero: A retrospective investigation

Maternal exposure to stress during pregnancy is associated with increased risk for cognitive and behavioral sequelae in offspring. Animal research demonstrates exposure to stress during gestation has effects on brain structure. In humans, however, little is known about the enduring effects of in utero exposure to maternal stress on brain morphology. We examine whether maternal report of stressful events during pregnancy is associated with brain structure and behavior in adolescents. We compare gray matter morphometry of typically-developing early adolescents (11-14 years of age, mean 12.7) at a single timepoint, based on presence/absence of retrospectively-assessed maternal report of negative major life event stress (MLES) during pregnancy: prenatal stress (PS; n = 28), comparison group (CG; n = 55). The Drug Use Screening Inventory Revised (DUSI-R) assessed adolescent risk for problematic behaviors. Exclusionary criteria included pre-term birth, low birth weight, and maternal substance use during pregnancy. Groups were equivalent for demographic (age, sex, IQ, SES, race/ethnicity), and birth measures (weight, length). Compared to CG peers, adolescents in the PS group exhibited increased gray matter density in bilateral posterior parietal cortex (PPC): bilateral intraparietal sulcus, left superior parietal lobule and inferior parietal lobule. Additionally, the PS group displayed greater risk for psychiatric symptoms and family system dysfunction, as assessed via DUSI-R subscales. These preliminary findings suggest that prenatal exposure to maternal MLES may exact enduring associations on offspring brain morphology and psychiatric risk, highlighting the importance of capturing these data in prospective longitudinal research studies (beginning at birth) to elucidate these associations.

Prosocial behavior relates to the rate and timing of cortical thinning from adolescence to young adulthood

Prosocial behavior, or voluntary actions that intentionally benefit others, relate to desirable developmental outcomes such as peer acceptance, while lack of prosocial behavior has been associated with several neurodevelopmental disorders. Mapping the biological foundations of prosociality may thus aid our understanding of both normal and abnormal development, yet how prosociality relates to cortical development is largely unknown. Here, relations between prosociality, as measured by the Strengths and Difficulties Questionnaire (self-report), and changes in thickness across the cortical mantle were examined using mixed-effects models. The sample consisted of 169 healthy individuals (92 females) aged 12-26 with repeated MRI from up to 3 time points, at approximately 3-year intervals (301 scans). In regions associated with social cognition and behavioral control, higher prosociality was associated with greater cortical thinning during early-to-middle adolescence, followed by attenuation of this process during the transition to young adulthood. Comparatively, lower prosociality was related to initially slower thinning, followed by comparatively protracted thinning into the mid-twenties. This study showed that prosocial behavior is associated with regional development of cortical thickness in adolescence and young adulthood. The results suggest that the rate of thinning in these regions, as well as its timing, may be factors related to prosocial behavior.

Combined effects of age and BMI are related to altered cortical thickness in adolescence and adulthood

Overweight and obesity are associated with functional and structural alterations in the brain, but how these associations change across critical developmental periods remains unknown. Here, we examined the relationship between age, body mass index (BMI) and cortical thickness (CT) in healthy adolescents (n = 70; 14-19 y) and adults (n = 75; 25-45 y). We also examined the relationship between adiposity, impulsivity, measured by delay discounting (DD), and CT of the inferior frontal gyrus (IFG), a region key to impulse control. A significant age-by-BMI interaction was observed in both adolescents and adults; however, the direction of this relationship differed between age groups. In adolescents, increased age-adjusted BMI Z-score attenuated age-related CT reductions globally and in frontal, temporal and occipital regions. In adults, increased BMI augmented age-related CT reductions, both globally and in bilateral parietal cortex. Although DD was unrelated to adiposity in both groups, increased DD and adiposity were both associated with reduced IFG thickness in adolescents and adults. Our findings suggest that the known age effects on CT in adolescence and adulthood are moderated by adiposity. The association between weight, cortical development and its functional implications would suggest that future studies of adolescent and adult brain development take adiposity into account.

Neuroimaging predictors of onset and course of depression in childhood and adolescence: A systematic review of longitudinal studies

Major depressive disorder (MDD) often emerges during adolescence with detrimental effects on development as well as lifetime consequences. Identifying neurobiological markers that are associated with the onset or course of this disorder in childhood and adolescence is important for early recognition and intervention and, potentially, for the prevention of illness onset. In this systematic review, 68 longitudinal neuroimaging studies, from 34 unique samples, that examined the association of neuroimaging markers with onset or changes in paediatric depression published up to 1 February 2019 were examined. These studies employed different imaging modalities at baseline; structural magnetic resonance imaging (MRI), diffusion tensor imaging (DTI), functional MRI (fMRI) or electroencephalography (EEG). Most consistent evidence across studies was found for blunted reward-related (striatal) activity (fMRI and EEG) as a potential biological marker for both MDD onset and course. With regard to structural brain measures, the results were highly inconsistent, likely caused by insufficient power to detect complex mediating effects of genetic and environmental factors in small sample sizes. Overall, there were a limited number of samples, and confounding factors such as sex and pubertal development were often not considered, whereas these factors are likely to be relevant especially in this age range.

Cortical morphometry in anorexia nervosa: An out-of-sample replication study

BACKGROUND

Acute anorexia nervosa (AN) is frequently accompanied by reduced global cortical volume. Investigations of local cortical alterations in AN have revealed widespread reduction in cortical thickness, gyrification, and curvature. The aim of the present study was to combine data from two previous studies to replicate previous findings.

METHODOLOGY

Magnetic resonance imaging (MRI) images from 46 adult women with AN and 54 age-matched healthy comparison (HC) women were analysed using FreeSurfer. Group differences in cortical volume and local cortical measures, including gyrification, curvature, thickness, and area, were examined controlling for dataset and age.

RESULTS

The AN group had reduced global cortical volume relative to the HC group. The AN group also had reduction in local cortical gyrification, small localised clusters of reduced cortical thickness, in the occipital and parietal cortices, and surface area in the frontal and temporal cortices. The AN group also had increased cortical thickness in the ACC relative to the HC participants.

CONCLUSIONS

The present findings replicate and validate previous findings of reduced global cortical volume and local gyrification in acute AN. The findings highlight the need for further investigation of local cortical folding, thickness, and surface area in AN to gain further insight into the biological underpinnings of AN.

Time-lagged associations between cognitive and cortical development from childhood to early adulthood

Throughout childhood and adolescence, humans experience marked changes in cortical structure and cognitive ability. Cortical thickness and surface area, in particular, have been associated with cognitive ability. Here we ask the question: What are the time-related associations between cognitive changes and cortical structure maturation. Identifying a developmental sequence requires multiple measurements of these variables from the same individuals across time. This allows capturing relations among the variables and, thus, finding whether (a) developmental cognitive changes follow cortical structure maturation, (b) cortical structure maturation follows cognitive changes, or (c) both processes influence each other over time. Four hundred and thiry children and adolescents (age range = 6.01-22.28 years) completed the Wechsler Abbreviated Scale of Intelligence battery and were MRI scanned at 3 time points separated by ≈2 years (Mage T1 = 10.60, SD = 3.58; Mage T2 = 12.63, SD = 3.62; Mage T3 = 14.49, SD = 3.55). Latent change score models were applied to quantify age-related relationships among the variables of interest. Our results indicate that cortical and cognitive changes related to each other reciprocally. Specifically, the magnitude or rate of the change in each variable at any occasion-and not the previous level-was predictive of later changes. These results were replicated for brain regions selected according to the coordinates identified in the Basten et al.'s (2015) meta-analysis, to the parieto-frontal integration theory (Jung & Haier, 2007) and to the whole cortex. Potential implications regarding brain plasticity and cognitive enhancement are discussed. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Exploration of gray matter correlates of cognitive training benefit in adolescents with chronic traumatic brain injury

Sustaining a traumatic brain injury (TBI) during adolescence has a profound effect on brain development and can result in persistent executive functioning deficits in daily life. Cognitive recovery from pediatric-TBI relies on the potential of neuroplasticity, which can be fostered by restorative training-programs. However the structural mechanisms underlying cognitive recovery in the immature brain are poorly understood. This study investigated gray matter plasticity following 2 months of cognitive training in young patients with TBI. Sixteen adolescents in the chronic stage of moderate-severe-TBI (9 male, mean age = 15y8m ± 1y7m) were enrolled in a cognitive computerized training program for 8 weeks (5 times/week, 40 min/session). Pre-and post-intervention, and 6 months after completion of the training, participants underwent a comprehensive neurocognitive test-battery and anatomical Magnetic Resonance Imaging scans. We selected 9 cortical-subcortical Regions-Of-Interest associated with Executive Functioning (EF-ROIs) and 3 control regions from the Desikan-Killiany atlas. Baseline analyses showed significant decreased gray matter density in the superior frontal gyri p = 0.033, superior parietal gyri p = 0.015 and thalamus p = 0.006 in adolescents with TBI compared to age and gender matched controls. Linear mixed model analyses of longitudinal volumetric data of the EF-ROI revealed no strong evidence of training-related changes in the group with TBI. However, compared to the change over time in the control regions between post-intervention and 6 months follow-up, the change in the EF-ROIs showed a significant difference. Exploratory analyses revealed a negative correlation between the change on the Digit Symbol Substitution test and the change in volume of the putamen (r = -0.596, p = 0.015). This preliminary study contributes to the insights of training-related plasticity mechanisms after pediatric-TBI.