White matter development in adolescence: the influence of puberty and implications for affective disorders

Spatiotemporal Patterns of White Matter Maturation after Pre-Adolescence: A Diffusion Kurtosis Imaging Study

Diffusion tensor imaging (DTI) enables the assessment of changes in brain tissue microstructure during maturation and ageing. In general, patterns of cerebral maturation and decline render non-monotonic lifespan trajectories of DTI metrics with age, and, importantly, the rate of microstructural changes is heterochronous for various white matter fibres. Recent studies have demonstrated that diffusion kurtosis imaging (DKI) metrics are more sensitive to microstructural changes during ageing compared to those of DTI. In a previous work, we demonstrated that the Cohen's d of mean diffusional kurtosis (dMK) represents a useful biomarker for quantifying maturation heterochronicity. However, some inferences on the maturation grades of different fibre types, such as association, projection, and commissural, were of a preliminary nature due to the insufficient number of fibres considered. Hence, the purpose of this follow-up work was to further explore the heterochronicity of microstructural maturation between pre-adolescence and middle adulthood based on DTI and DKI metrics. Using the effect size of the between-group parametric changes and Cohen's d, we observed that all commissural fibres achieved the highest level of maturity, followed by the majority of projection fibres, while the majority of association fibres were the least matured. We also demonstrated that dMK strongly correlates with the maxima or minima of the lifespan curves of DTI metrics. Furthermore, our results provide substantial evidence for the existence of spatial gradients in the timing of white matter maturation. In conclusion, our data suggest that DKI provides useful biomarkers for the investigation of maturation spatial heterogeneity and heterochronicity.

A daily diary study of discrimination and distress in Mexican-origin adolescents: Testing mediating mechanisms

The present 21-day daily diary study (conducted 2021-2022) tested anger and racism-related vigilance as potential transdiagnostic mediators linking exposure to racial and ethnic discrimination (RED) to distress (negative affect and stress, respectively). The data analytic sample included N = 317 Mexican-origin adolescents (Mage = 13.5 years; 50.8% male, 46.7% female; 2.5% non-binary) from the Midwestern United States. Results from longitudinal mediation models revealed significant mediation effects through anger and racism-related vigilance, respectively, in the association between daily RED and daily distress, both within and across adolescents. Implications for theory, research, and practice are discussed so that future work can leverage these novel findings toward promoting the well-being of Mexican-origin adolescents, especially those who live in contexts of ethnoracial adversity.

Pathophysiology in cortico-amygdala circuits and excessive aversion processing: the role of oligodendrocytes and myelination

Stress-related psychiatric illnesses, such as major depressive disorder, anxiety and post-traumatic stress disorder, present with alterations in emotional processing, including excessive processing of negative/aversive stimuli and events. The bidirectional human/primate brain circuit comprising anterior cingulate cortex and amygdala is of fundamental importance in processing emotional stimuli, and in rodents the medial prefrontal cortex-amygdala circuit is to some extent analogous in structure and function. Here, we assess the comparative evidence for: (i) Anterior cingulate/medial prefrontal cortex<->amygdala bidirectional neural circuits as major contributors to aversive stimulus processing; (ii) Structural and functional changes in anterior cingulate cortex<->amygdala circuit associated with excessive aversion processing in stress-related neuropsychiatric disorders, and in medial prefrontal cortex<->amygdala circuit in rodent models of chronic stress-induced increased aversion reactivity; and (iii) Altered status of oligodendrocytes and their oligodendrocyte lineage cells and myelination in anterior cingulate/medial prefrontal cortex<->amygdala circuits in stress-related neuropsychiatric disorders and stress models. The comparative evidence from humans and rodents is that their respective anterior cingulate/medial prefrontal cortex<->amygdala circuits are integral to adaptive aversion processing. However, at the sub-regional level, the anterior cingulate/medial prefrontal cortex structure-function analogy is incomplete, and differences as well as similarities need to be taken into account. Structure-function imaging studies demonstrate that these neural circuits are altered in both human stress-related neuropsychiatric disorders and rodent models of stress-induced increased aversion processing. In both cases, the changes include altered white matter integrity, albeit the current evidence indicates that this is decreased in humans and increased in rodent models. At the cellular-molecular level, in both humans and rodents, the current evidence is that stress disorders do present with changes in oligodendrocyte lineage, oligodendrocytes and/or myelin in these neural circuits, but these changes are often discordant between and even within species. Nonetheless, by integrating the current comparative evidence, this review provides a timely insight into this field and should function to inform future studies-human, monkey and rodent-to ascertain whether or not the oligodendrocyte lineage and myelination are causally involved in the pathophysiology of stress-related neuropsychiatric disorders.

The Role of Puberty and Sex on Brain Structure in Adolescents With Anxiety Following Concussion

BACKGROUND

Adolescence represents a window of vulnerability for developing psychological symptoms following concussion, especially in girls. Concussion-related lesions in emotion regulation circuits may help explain these symptoms. However, the contribution of sex and pubertal maturation remains unclear. Using the neurite density index (NDI) in emotion regulation tracts (left/right cingulum bundle [CB], forceps minor [FMIN], and left/right uncinate fasciculus), we sought to elucidate these relationships.

METHODS

No adolescent had a history of anxiety and/or depression. The Screen for Child Anxiety Related Emotional Disorders and Children's Depression Rating Scale were used at scan to assess anxiety and depressive symptoms in 55 concussed adolescents (41.8% girls) and 50 control adolescents with no current/history of concussion (44% girls). We evaluated if a mediation-moderation model including the NDI (mediation) and sex or pubertal status (moderation) could help explain this relationship.

RESULTS

Relative to control adolescents, concussed adolescents showed higher anxiety (p = .003) and lower NDI, with those at more advanced pubertal maturation showing greater abnormalities in 4 clusters: the left CB frontal (p = .002), right CB frontal (p = .011), FMIN left-sided (p = .003), and FMIN right-sided (p = .003). Across all concussed adolescents, lower NDI in the left CB frontal and FMIN left-sided clusters partially mediated the association between concussion and anxiety, with the CB being specific to female adolescents. These effects did not explain depressive symptoms.

CONCLUSIONS

Our findings indicate that lower NDI in the CB and FMIN may help explain anxiety following concussion and that adolescents at more advanced (vs less advanced) status of pubertal maturation may be more vulnerable to concussion-related injuries, especially in girls.

Social jetlag longitudinally predicts internalizing and externalizing behavior for adolescent females, but not males

Biological changes contribute to preferences for later bed and wake times during adolescence, yet the social constraints of school start times necessitate early wake times. This often results in social jetlag (i.e. misalignment between preferred sleep timing on weekends and school days). We examined whether social jetlag predicts adolescent internalizing and externalizing behavior over time and/or whether associations differ based on sex. We used data from the National Institute of Child Health and Human Development Study of Early Child Care and Youth Development Study (n = 767) to test whether social jetlag at 6th grade (ages 12-13 years) predicted internalizing and externalizing behavior at age 15 years and whether child sex moderated associations. Controlling for internalizing and externalizing behavior at 6th grade (ages 12-13 years), results were that social jetlag at 6th grade (ages 12-13 years) predicted more internalizing and externalizing behaviors at age 15 for females, but not males. These findings show that social jetlag during early adolescence confers risk for internalizing and externalizing behavior in females at mid-adolescence. Greater attention should be placed on identifying and addressing social jetlag in adolescent females.

The sex-dependent and enduring impact of pubertal stress on health and disease

Illness is often predicated long before the manifestation of its symptoms. Exposure to stressful experiences particularly during critical periods of development, such as puberty and adolescence, can induce various physical and mental illnesses. Puberty is a critical period of maturation for neuroendocrine systems, such as the hypothalamic-pituitary-gonadal (HPG) and hypothalamic-pituitary-adrenal (HPA) axes. Exposure to adverse experiences during puberty can impede normal brain reorganizing and remodelling and result in enduring consequences on brain functioning and behaviour. Stress responsivity differs between the sexes during the pubertal period. This sex difference is partly due to differences in circulating sex hormones between males and females, impacting stress and immune responses differently. The effects of stress during puberty on physical and mental health remains under-examined. The purpose of this review is to summarize the most recent findings pertaining to age and sex differences in HPA axis, HPG axis, and immune system development, and describe how disruption in the functioning of these systems can propagate disease. Lastly, we delve into the notable neuroimmune contributions, sex differences, and the mediating role of the gut microbiome on stress and health outcomes. Understanding the enduring consequences of adverse experiences during puberty on physical and mental health will allow a greater proficiency in treating and preventing stress-related diseases early in development.

Prefrontal, parietal, and limbic condition-dependent differences in bipolar disorder: a large-scale meta-analysis of functional neuroimaging studies

BACKGROUND

Over the past few decades, neuroimaging research in Bipolar Disorder (BD) has identified neural differences underlying cognitive and emotional processing. However, substantial clinical and methodological heterogeneity present across neuroimaging experiments potentially hinders the identification of consistent neural biomarkers of BD. This meta-analysis aims to comprehensively reassess brain activation and connectivity in BD in order to identify replicable differences that converge across and within resting-state, cognitive, and emotional neuroimaging experiments.

METHODS

Neuroimaging experiments (using fMRI, PET, or arterial spin labeling) reporting whole-brain results in adults with BD and controls published from December 1999-June 18, 2019 were identified via PubMed search. Coordinates showing significant activation and/or connectivity differences between BD participants and controls during resting-state, emotional, or cognitive tasks were extracted. Four parallel, independent meta-analyses were calculated using the revised activation likelihood estimation algorithm: all experiment types, all resting-state experiments, all cognitive experiments, and all emotional experiments. To confirm reliability of identified clusters, two different meta-analytic significance tests were employed.

RESULTS

205 published studies yielding 506 individual neuroimaging experiments (150 resting-state, 134 cognitive, 222 emotional) comprising 5745 BD and 8023 control participants were included. Five regions survived both significance tests. Individuals with BD showed functional differences in the right posterior cingulate cortex during resting-state experiments, the left amygdala during emotional experiments, including those using a mixed (positive/negative) valence manipulation, and the left superior and right inferior parietal lobules during cognitive experiments, while hyperactivating the left medial orbitofrontal cortex during cognitive experiments. Across all experiments, there was convergence in the right caudate extending to the ventral striatum, surviving only one significance test.

CONCLUSIONS

Our findings indicate reproducible localization of prefrontal, parietal, and limbic differences distinguishing BD from control participants that are condition-dependent, despite heterogeneity, and point towards a framework for identifying reproducible differences in BD that may guide diagnosis and treatment.

Fronto-amygdala resting state functional connectivity is associated with anxiety symptoms among adolescent girls more advanced in pubertal maturation

Early adolescence, with the onset of puberty, is an important period when sex differences in anxiety emerge, with girls reporting significantly higher anxiety symptoms than boys. This study examined the role of puberty on fronto-amygdala functional connectivity and risk of anxiety symptoms in 70 girls (age 11-13) who completed a resting state fMRI scan, self-report measures of anxiety symptoms and pubertal status, and provided basal testosterone levels (64 girls). Resting state fMRI data were preprocessed using fMRIPrep and connectivity indices were extracted from ventromedial prefrontal cortex (vmPFC) and amygdala regions-of-interest. We tested moderated mediation models and hypothesized that vmPFC-amygdala would mediate the relation between three indices of puberty (testosterone and adrenarcheal/gonadarcheal development) and anxiety, with puberty moderating the relation between connectivity and anxiety. Results showed a significant moderation effect of testosterone and adrenarcheal development in the right amygdala and a rostral/dorsal area of the vmPFC and of gonadarcheal development in the left amygdala and a medial area of the vmPFC on anxiety symptoms. Simple slope analyses showed that vmPFC-amygdala connectivity was negatively associated with anxiety only in girls more advanced in puberty suggesting that sensitivity to the effects of puberty on fronto-amygdala function could contribute to risk for anxiety disorders among adolescent girls.

Frequency-dependent alterations in regional homogeneity associated with puberty hormones in girls with central precocious puberty: A resting-state fMRI study

OBJECTIVE

Central precocious puberty (CPP) patients are at significantly higher risk of emotional, mental, and behavioral disorders than those normal pubertal population. However, to date, the definite mechanism of how puberty hormones affect patients with CPP remains unclear. This regional homogeneity (ReHo) study aimed to explore the impact of premature hypothalamus-pituitary-gonadal (HPG) axis activation on brain function alteration in girls with CPP, meanwhile, to explore the relationship between gonadotropin and gonadal hormones levels, abnormal brain activity and cognitive function.

METHODS

In this prospective study, a total of 85 girls who were suspected of having CPP were enrolled from the Child Healthcare Department of the Second Affiliated Hospital of Wenzhou Medical University Hospital from June 2018 to May 2021, including 41 CPP girls and 44 non-CPP girls. All participants collected the 0, 30, 60 min blood luteinizing hormone (LH), follicle-stimulating hormone (FSH), 0, 30 min estradiol (E2) and baseline cortisol (COR) and prolactin (PRL) concentrations after gonadotrophin-releasing hormone (GnRH) stimulating test. Resting-state magnetic resonance imaging (rs-MRI) scans were performed for all participants at 2 weeks before the GnRH stimulating test, voxel-wise ReHo was calculated in the standard frequency band (0.01-0.10 Hz), and in slow-4 (0.027-0.073 Hz) and slow-5 (0.01-0.027 Hz). Wechsler Intelligence Scale for Children Fourth Edition (WISC-IV) was also collected. Independent-sample t-test or Mann-Whitney U test was used to compare the differences between two groups. The correlation analysis among abnormal brain regions, serum hormone levels and WISC-IV scores were performed by Spearman or partial correlation analysis.

RESULTS

Compared to the non-CPP group, the CPP group showed higher regional homogeneity (ReHo) values in the left inferior temporal gyrus (ITG.L), as well as lower ReHo values in left superior temporal gyrus (STG.L), left superior occipital gyrus (SOG.L) and the right middle gyrus (MTG.R) in slow4.in slow5 frequency band, CPP group demonstrated decreased ReHo values in bilateral orbital part of superior frontal gyrus and medial superior frontal gyrus.

LIMITATION

Due to the cross-section design of this study, further research is needed to explore the relationships between age, premature activation HPG axis and brain function changes.

CONCLUSION

Our findings demonstrate that premature HPG axis activation and alterations in puberty hormones, may lead to changes in brain activity and cognitive function. This rs-fMRI study may enhance our understanding of the neuroendocrine mechanisms of mood, behavior, and cognitive function alterations in patients with CPP.

The effects of puberty and sex on adolescent white matter development: A systematic review

Adolescence, the transition between childhood and adulthood, is characterized by rapid brain development in white matter (WM) that is attributed in part to rising levels in adrenal and gonadal hormones. The extent to which pubertal hormones and related neuroendocrine processes explain sex differences in WM during this period is unclear. In this systematic review, we sought to examine whether there are consistent associations between hormonal changes and morphological and microstructural properties of WM across species and whether these effects are sex-specific. We identified 90 (75 human, 15 non-human) studies that met inclusion criteria for our analyses. While studies in human adolescents show notable heterogeneity, results broadly demonstrate that increases in gonadal hormones across pubertal development are associated with macro- and microstructural changes in WM tracts that are consistent with the sex differences found in non-human animals, particularly in the corpus callosum. We discuss limitations of the current state of the science and recommend important future directions for investigators in the field to consider in order to advance our understanding of the neuroscience of puberty and to promote forward and backward translation across model organisms.

Puberty contributes to adolescent development of fronto-striatal functional connectivity supporting inhibitory control

Adolescence is defined by puberty and represents a period characterized by neural circuitry maturation (e.g., fronto-striatal systems) facilitating cognitive improvements. Though studies have characterized age-related changes, the extent to which puberty influences maturation of fronto-striatal networks is less known. Here, we combine two longitudinal datasets to characterize the role of puberty in the development of fronto-striatal resting-state functional connectivity (rsFC) and its relationship to inhibitory control in 106 10-18-year-olds. Beyond age effects, we found that puberty was related to decreases in rsFC between the caudate and the anterior vmPFC, rostral and ventral ACC, and v/dlPFC, as well as with rsFC increases between the dlPFC and nucleus accumbens (NAcc) across males and females. Stronger caudate rsFC with the dlPFC and vlPFC during early puberty was associated with worse inhibitory control and slower correct responses, respectively, whereas by late puberty, stronger vlPFC rsFC with the dorsal striatum was associated with faster correct responses. Taken together, our findings suggest that certain fronto-striatal connections are associated with pubertal maturation beyond age effects, which, in turn are related to inhibitory control. We discuss implications of puberty-related fronto-striatal maturation to further our understanding of pubertal effects related to adolescent cognitive and affective neurodevelopment.

The association between age at menarche and chronic pain outcomes in women: the Tromsø Study, 2007 to 2016

ABSTRACT

Sex differences in chronic pain are well established with documented predominance in women. This study assessed relationships between age at menarche and chronic pain, site-specific chronic pain, pain characteristics, and chronic widespread pain (CWP). We used data from the Tromsø Study conducted in 2007 to 2008 and 2015 to 2016 (Tromsø 6 and Tromsø 7 waves) including participants aged 30 to 99 years. The associations between age at menarche and chronic pain were examined in Tromsø 6 (n = 6449), Tromsø 7 (n = 5681), and the combination of Tromsø 6 and Tromsø 7 (n = 12,130). Tromsø 7 data were used further to examine the associations between age at menarche and site-specific chronic pain, 4 pain characteristics (pain duration, pain intensity, episode duration, and episode frequency), and CWP. All analyses were adjusted for body mass index, age, and economic status of the household in childhood. Lower age at menarche was associated with an increased risk of chronic pain in all 3 samples (risk ratio for each year delay in menarche 0.98, 95% CI [0.97 to 0.99] across samples). Risk differences were -0.014, CI 95% (-0.02 to -0.005) in Tromsø 6, -0.011, CI 95% (-0.02 to -0.02) in Tromsø 7, and -0.012, CI 95% (-0.02 to -0.01) in the combined sample. Age at menarche was significantly associated with chronic pain in the neck, abdomen, and both arms, and CWP. Of the 4 pain characteristics, pain duration was statistically significant. We conclude that early menarche is an independent risk factor for pain across a broad spectrum of pain outcomes.

Automated Multiclass Artifact Detection in Diffusion MRI Volumes via 3D Residual Squeeze-and-Excitation Convolutional Neural Networks

Diffusion MRI (dMRI) is widely used to investigate neuronal and structural development of brain. dMRI data is often contaminated with various types of artifacts. Hence, artifact type identification in dMRI volumes is an essential pre-processing step prior to carrying out any further analysis. Manual artifact identification amongst a large pool of dMRI data is a highly labor-intensive task. Previous attempts at automating this process are often limited to a binary classification ("poor" vs. "good" quality) of the dMRI volumes or focus on detecting a single type of artifact (e.g., motion, Eddy currents, etc.). In this work, we propose a deep learning-based automated multiclass artifact classifier for dMRI volumes. Our proposed framework operates in 2 steps. In the first step, the model predicts labels associated with 3D mutually exclusive collectively exhaustive (MECE) sub-volumes or "slabs" extracted from whole dMRI volumes. In the second step, through a voting process, the model outputs the artifact class present in the whole volume under investigation. We used two different datasets for training and evaluating our model. Specifically, we utilized 2,494 poor-quality dMRI volumes from the Adolescent Brain Cognitive Development (ABCD) and 4,226 from the Healthy Brain Network (HBN) dataset. Our results demonstrate accurate multiclass volume-level main artifact type prediction with 96.61 and 97.52% average accuracies on the ABCD and HBN test sets, respectively. Finally, in order to demonstrate the effectiveness of the proposed framework in dMRI pre-processing pipelines, we conducted a proof-of-concept dMRI analysis exploring the relationship between whole-brain fractional anisotropy (FA) and participant age, to test whether the use of our model improves the brain-age association.

Multimethod assessment of pubertal timing and associations with internalizing psychopathology in early adolescent girls

Early pubertal timing has consistently been associated with internalizing psychopathology in adolescent girls. Here, we aimed to examine whether the association between timing and mental health outcomes varies by measurement of pubertal timing and internalizing psychopathology, differs between adrenarcheal and gonadarcheal processes, and is stronger concurrently or prospectively. We assessed 174 female adolescents (age 10.0-13.0 at Time 1) twice, with an 18-month interval. Participants provided self-reported assessments of depression/anxiety symptoms and pubertal development, subjective pubertal timing, and date of menarche. Their parents/guardians also reported on the adolescent's pubertal development and subjective pubertal timing. We assessed salivary dehydroepiandrosterone (DHEA), testosterone, and estradiol levels and conducted clinical interviews to determine the presence of case level internalizing disorders. From these data, we computed 11 measures of pubertal timing at both time points, as well as seven measures of internalizing psychopathology, and entered these in a Specification Curve Analysis. Overall, earlier pubertal timing was associated with increased internalizing psychopathology. Associations were stronger prospectively than concurrently, suggesting that timing of early pubertal processes might be especially important for later risk of mental illness. Associations were strongest when pubertal timing was based on the Tanner Stage Line Drawings and when the outcome was case-level Diagnostic and Statistical Manual of Mental Disorders, 4th edition (DSM-IV) depression or Hierarchical Taxonomy of Psychopathology (HiTOP) distress disorders. Timing based on hormone levels was not associated with internalizing psychopathology, suggesting that psychosocial mechanisms, captured by timing measures of visible physical characteristics might be more meaningful determinants of internalizing psychopathology than biological ones in adolescent girls. Future research should precisely examine these psychosocial mechanisms. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Automatic Volumetric Quality Assessment of Diffusion MR Images via Convolutional Neural Network Classifiers

Diffusion Tensor Imaging (DTI) is widely used to find brain biomarkers for various stages of brain structural and neuronal development. Processing DTI data requires a detailed Quality Assessment (QA) to detect artifactual volumes amongst a large pool of data. Since large cohorts of brain DTI data are often used in different studies, manual QA of such images is very labor-intensive. In this paper, a deep learning-based tool is developed for quick automatic QA of 3D raw diffusion MR images. We propose a 2-step framework to automate the process of binary (i.e., 'good' vs 'poor') quality classification of diffusion MR images. In the first step, using two separately trained 3D convolutional neural networks with different input sizes, quality labels for individual Regions of Interest (ROIs) sampled from whole DTI volumes are predicted. In the second step, two distinct novel voting systems are designed and fine-tuned to predict the quality label of whole brain DTI volumes using the individual ROI labels predicted in the previous step. Our results demonstrate the validity and practicality of our tool. Specifically, using a balanced dataset of 6,940 manually-labeled 3D DTI volumes from 85 unique subjects for training, validation, and testing, our model achieves 100% accuracy via one voting system, and 98% accuracy via another voting system on the same test set.

Age related sex differences in maladaptive regulatory responses to sadness: A study of youths at high and low familial risk for depression

Offspring of parents with depression histories are at increased risk of developing depression and also report maladaptive ways of self-regulating sadness. Maladaptive regulation of sadness tends to be more prevalent among females than males and has been proposed as one explanation of sex differences in depression rates that emerge around mid-adolescence. However, there is scant information about the age at which the sex differences in maladaptive regulatory responses become evident and whether such age-related sex differences vary depending on depression risk. The present study examined two samples aged 8-18 years: 86 offspring of emotionally healthy parents and 98 offspring of parents with depression histories. Subjects were clinically assessed and provided self-reports of maladaptive responses to sadness. In the combined samples, sex differences in maladaptive responses were significant at age 12.5 years and older ages (i.e., chronologically earlier than the documented emergence of sex differences in depression). While in the high-risk group, sex differences in maladaptive regulatory responses were significant at 12.11 years of age and older, in the low-risk group there was no age at which sex differences were significant. Our findings support the possible mechanistic role of maladaptive emotion regulation in the emergence of sex disparities in depression rates and have implications for prevention.

White matter microstructural integrity correlates of emotion dysregulation in children with ADHD: A diffusion imaging tractography study

BACKGROUND

Emotion dysregulation (ED) is prevalent in youths with attention-deficit hyperactivity disorder (ADHD) and causes more social impairment and poor adaptive function. Alterations in the integrity of white matter (WM) tracts might have important implications for affective processing related to ED. However, little is known about the WM correlates underpinning ED in ADHD.

METHODS

Using diffusion spectrum image tractography, we obtained generalized fractional anisotropy (GFA) values of 76 WM tracts in 77 children with ADHD and 105 typically developing controls (TDC). ED severity was defined by the dysregulation profile from the child behavior checklist. Canonical correlation analysis (CCA) was performed to identify modes that relate WM microstructural property to ED severity and cognitive measures.

RESULTS

The application of CCA identified one significant mode (r = 0.638, FWE-corrected p = 0.046) of interdependencies between WM property patterns and diagnosis, ADHD total symptom levels, dysregulation by diagnosis interaction, and full-scale intellectual quotient (FIQ). GFA values of 19 WM tracts that were linked to affective-processing, sensory-processing and integration, and cognitive control circuitry were positively correlated with ED severity in TDC but negatively correlated with ED severity in ADHD. ADHD symptom severity and diagnosis were negatively associated with the GFA patterns of this set of tract bundles. In contrast, FIQ was positively correlated with this set of tract bundles.

CONCLUSIONS

This study used the CCA to show that children with ADHD and TDC had distinct multivariate associations between ED severity (diagnosis by ED interaction) and microstructural property in a set of WM tracts. These tracts interconnect the cortical regions that are principally involved in emotion processing, integration, and cognitive control in multiple brain systems. The WM microstructure integrity impairment might be an essential correlate of emotion dysregulation in ADHD.

As they wait: Anticipatory neural response to evaluative peer feedback varies by pubertal status and social anxiety

Adolescence is a developmental period characterized by substantial biological, neural, behavioral, and social changes. Learning to navigate the complex social world requires adaptive skills. Although anticipation of social situations can serve an adaptive function, providing opportunity to adjust behavior, socially anxious individuals may engage in maladaptive anticipatory processing. Importantly, elevated social anxiety often coincides with adolescence. This study investigated cortical electroencephalogram (EEG) responses during anticipation of evaluative feedback in 106 healthy adolescents aged 12–17 years. We examined differences in anticipatory event-related potentials (i.e., stimulus preceding negativity [SPN]) in relation to social anxiety levels and pubertal maturation. As expected, the right frontal SPN was more negative during feedback anticipation, particularly for adolescents with higher social anxiety and adolescents who were at a more advanced pubertal stage. Effects for the left posterior SPN were the opposite of those for the right frontal SPN consistent with a dipole. Anticipatory reactivity in adolescence was related to social anxiety symptom severity, especially in females, and pubertal maturation in a social evaluative situation. This study provides evidence for the development of social anticipatory processes in adolescence and potential mechanisms underlying maladaptive anticipation in social anxiety.

Autism - A Comprehensive Array of Prominent Signs and Symptoms

BACKGROUND

Autism Spectrum Disorder (ASD) is a multifaceted neurodevelopmental condition characterized by multiple psychological and physiological impairments in young children. According to the recent reports, 1 out of every 58 newly-born children is suffering from autism. The aetiology of the disorder is complex and poorly understood, hindering the adaptation of targeted and effective therapies. There are no well- established diagnostic biomarkers for autism. Hence the analysis of symptoms by the pediatricians plays a critical role in the early intervention.

METHODS

In the present report, we have emphasized 24 behavioral, psychological and clinical symptoms of autism.

RESULTS

Impaired social interaction, restrictive and narrow interests, anxiety, depression; aggressive, repetitive, rigid and self-injurious behavior, lack of consistency, short attention span, fear, shyness and phobias, hypersensitivity and rapid mood alterations, high level of food and toy selectivity; inability to establish friendships or follow the instructions; fascination by round spinning objects and eating non-food materials are common psychological characteristics of autism. Speech or hearing impairments, poor cognitive function, gastrointestinal problems, weak immunity, disturbed sleep and circadian rhythms, weak motor neuromuscular interaction, lower level of serotonin and neurotransmitters, headache and body pain are common physiological symptoms.

CONCLUSION

A variable qualitative and quantitative impact of this wide range of symptoms is perceived in each autistic individual, making him/her distinct, incomparable and exceptional. Selection and application of highly personalized medical and psychological therapies are therefore recommended for the management and treatment of autism.

Coming of age in the frontal cortex: The role of puberty in cortical maturation

Across species, adolescence is a period of growing independence that is associated with the maturation of cognitive, social, and affective processing. Reorganization of neural circuits within the frontal cortex is believed to contribute to the emergence of adolescent changes in cognition and behavior. While puberty coincides with adolescence, relatively little is known about which aspects of frontal cortex maturation are driven by pubertal development and gonadal hormones. In this review, we highlight existing work that suggests puberty plays a role in the maturation of specific cell types in the medial prefrontal cortex (mPFC) of rodents, and highlight possible routes by which gonadal hormones influence frontal cortical circuit development.

The NIMH Intramural Longitudinal Study of the Endocrine and Neurobiological Events Accompanying Puberty: Protocol and rationale for methods and measures

Delineating the relationship between human neurodevelopment and the maturation of the hypothalamic-pituitary-gonadal (HPG) axis during puberty is critical for investigating the increase in vulnerability to neuropsychiatric disorders that is well documented during this period. Preclinical research demonstrates a clear association between gonadal production of sex steroids and neurodevelopment; however, identifying similar associations in humans has been complicated by confounding variables (such as age) and the coactivation of two additional endocrine systems (the adrenal androgenic system and the somatotropic growth axis) and requires further elucidation. In this paper, we present the design of, and preliminary observations from, the ongoing NIMH Intramural Longitudinal Study of the Endocrine and Neurobiological Events Accompanying Puberty. The aim of this study is to directly examine how the increase in sex steroid hormone production following activation of the HPG-axis (i.e., gonadarche) impacts neurodevelopment, and, additionally, to determine how gonadal development and maturation is associated with longitudinal changes in brain structure and function in boys and girls. To disentangle the effects of sex steroids from those of age and other endocrine events on brain development, our study design includes 1) selection criteria that establish a well-characterized baseline cohort of healthy 8-year-old children prior to the onset of puberty (e.g., prior to puberty-related sex steroid hormone production); 2) temporally dense longitudinal, repeated-measures sampling of typically developing children at 8-10 month intervals over a 10-year period between the ages of eight and 18; 3) contemporaneous collection of endocrine and other measures of gonadal, adrenal, and growth axis function at each timepoint; and 4) collection of multimodal neuroimaging measures at these same timepoints, including brain structure (gray and white matter volume, cortical thickness and area, white matter integrity, myelination) and function (reward processing, emotional processing, inhibition/impulsivity, working memory, resting-state network connectivity, regional cerebral blood flow). This report of our ongoing longitudinal study 1) provides a comprehensive review of the endocrine events of puberty; 2) details our overall study design; 3) presents our selection criteria for study entry (e.g., well-characterized prepubertal baseline) along with the endocrinological considerations and guiding principles that underlie these criteria; 4) describes our longitudinal outcome measures and how they specifically relate to investigating the effects of gonadal development on brain development; and 5) documents patterns of fMRI activation and resting-state networks from an early, representative subsample of our cohort of prepubertal 8-year-old children.

Greater age-related changes in white matter morphometry following early life stress: Associations with internalizing problems in adolescence

Early life stress (ELS) is associated with increased risk for internalizing disorders and variations in gray matter development. It is unclear, however, whether ELS affects normative age-related changes in white matter (WM) morphology, and if such maturational differences are associated with risk for internalizing psychopathology. We conducted comprehensive interviews in a cross-sectional sample of young adolescents (N = 156; 89 F; Ages 9-14) to assess lifetime exposure to stress and objective cumulative ELS severity. We used diffusion-weighted imaging to measure WM fixel-based morphometry and tested the effects of age and ELS on WM fiber density and cross-section (FDC), and associations between WM FDC and internalizing problems. Age was positively associated with FDC in all WM tracts; greater ELS severity was related to stronger age-WM associations in several association tracts connecting the frontal lobes with limbic, parietal, and occipital regions, including bilateral superior and inferior longitudinal and uncinate fasciculi (UF). Among older adolescents with greater ELS severity, a higher UF FDC was associated with fewer internalizing problems. Greater ELS severity predicted more mature WM morphometry in tracts implicated in emotion regulation and cognitive processing. More phenotypically mature UF WM may be adaptive against internalizing psychopathology in adolescents exposed to ELS.

Consensus Parameter: Research Methodologies to Evaluate Neurodevelopmental Effects of Pubertal Suppression in Transgender Youth

Purpose: Pubertal suppression is standard of care for early pubertal transgender youth to prevent the development of undesired and distressing secondary sex characteristics incongruent with gender identity. Preliminary evidence suggests pubertal suppression improves mental health functioning. Given the widespread changes in brain and cognition that occur during puberty, a critical question is whether this treatment impacts neurodevelopment.

Methods: A Delphi consensus procedure engaged 24 international experts in neurodevelopment, gender development, puberty/adolescence, neuroendocrinology, and statistics/psychometrics to identify priority research methodologies to address the empirical question: is pubertal suppression treatment associated with real-world neurocognitive sequelae? Recommended study approaches reaching 80% consensus were included in the consensus parameter.

Results: The Delphi procedure identified 160 initial expert recommendations, 44 of which ultimately achieved consensus. Consensus study design elements include the following: a minimum of three measurement time points, pubertal staging at baseline, statistical modeling of sex in analyses, use of analytic approaches that account for heterogeneity, and use of multiple comparison groups to minimize the limitations of any one group. Consensus study comparison groups include untreated transgender youth matched on pubertal stage, cisgender (i.e., gender congruent) youth matched on pubertal stage, and an independent sample from a large-scale youth development database. The consensus domains for assessment includes: mental health, executive function/cognitive control, and social awareness/functioning.

Conclusion: An international interdisciplinary team of experts achieved consensus around primary methods and domains for assessing neurodevelopmental effects (i.e., benefits and/or difficulties) of pubertal suppression treatment in transgender youth.

Sex differences in pubertal associations with fronto-accumbal white matter morphometry: Implications for understanding sensitivity to reward and punishment

Researchers have reported sex-differentiated maturation of white matter (WM) during puberty. It is not clear, however, whether such distinctions contribute to documented sex differences in sensitivity to reward and punishment during adolescence. Given the role of the orbitofrontal cortex (OFC) and nucleus accumbens (NAcc) in reward and punishment-related behaviors, we tested in a cross-sectional study whether males and females (N = 156, 89 females; ages 9-14 years) differ in the association between pubertal stage and fixel-based morphometry of WM fibers connecting the OFC and NAcc (i.e., the fronto-accumbal tract). Further, we examined whether males and females differ in associations between fronto-accumbal WM measures and self-reported sensitivity to reward and punishment. Pubertal stage was positively associated with fronto-accumbal fiber density and cross-section (FDC) in males, but not in females. Consistent with previous reports, males reported higher reward sensitivity than did females, although fronto-accumbal combined FDC was not related to reward sensitivity in either sex. Meanwhile, only males showed a negative association between fronto-accumbal tract FDC and sensitivity to punishment. Follow-up analyses revealed that fiber cross-section, but not density, was related to pubertal stage and punishment sensitivity in males, as well as to reward sensitivity in all participants. Our findings suggest there are sex differences in puberty-related maturation of the fronto-accumbal tract, and this tract is related to lower punishment sensitivity in adolescent males compared to females.

Sex-specific associations between co-exposure to multiple metals and visuospatial learning in early adolescence

The predisposition, severity, and progression of many diseases differ between males and females. Sex-related differences in susceptibility to neurotoxicant exposures may provide insight into the cause of the observed discrepancy. Early adolescence, a period of substantial structural and functional brain changes, may present a critical window of vulnerability to environmental exposures. This study aimed to examine sex-specific associations between co-exposure to multiple metals and visuospatial memory in early adolescence. Manganese (Mn), lead (Pb), chromium (Cr), and copper (Cu) were measured in blood, urine, hair, nails, and saliva of 188 participants (88 girls; 10-14 years of age). Visuospatial memory skills were assessed using a computerized maze task, the virtual radial arm maze (VRAM). Using generalized weighted quantile sum regression, we investigated sex-specific associations between the combined effect of exposure to the metal mixture and visuospatial working memory and determined the contribution of each component to the outcome. The results suggest that sex moderates the association between the metal mixture and visuospatial learning for all outcomes measured. In girls, exposure was associated with slower visuospatial learning and driven by Mn and Cu. In boys, exposure was associated with faster visuospatial learning, and driven by Cr. These results suggest that (a) the effect of metal co-exposure on learning differs in magnitude, and in the direction between sexes, and (b) early adolescence may be a sensitive developmental period for metal exposure.

Longitudinal patterns of white matter fibre density and morphology in children are associated with age and pubertal stage

The pubertal period involves dynamic white matter development. This period also corresponds with rapid gains in higher cognitive functions including attention, as well as increased risk of developing mental health difficulties. This longitudinal study comprised children aged 9-13 years (n = 130). Diffusion magnetic resonance imaging (dMRI) data were acquired (b = 2800s/mm2, 60 directions) at two time-points. We derived measures of fibre density and morphology using the fixel-based analysis framework and performed a tract-based mixed-effects modelling analysis to understand patterns of white matter development with respect to age, sex, pubertal stage, and the change in pubertal stage. We observed significant increases in apparent fibre density across a large number of white matter pathways, including major association and commissural pathways. We observed a linear relationship between pubertal stage and fibre density and morphology in the right superior longitudinal fasciculus, and fibre morphology in the right inferior longitudinal fasciculus. Finally, we report a significant interaction between the change in pubertal stage and age in the development of fibre density, for left-lateralised association tracts. Overall, white matter development across ages 9-13 years involves the expansion of major white matter fibre pathways, with key association pathways linked with pubertal stage.

The Roles of Physical Activity, Exercise, and Fitness in Promoting Resilience During Adolescence: Effects on Mental Well-Being and Brain Development

Adolescence is a critical yet vulnerable period for developing behaviors important for mental well-being. The existing literature suggests that physical activity (PA), exercise, and aerobic fitness promote well-being and reduce risk of mental health problems. In this review, we focus on PA, exercise, and fitness as modifiable resilience factors that may help promote self-regulation via strengthening of top-down control of bottom-up processes in the brain, thereby acting as a buffer against mental health problems during this period of vulnerability. First, we briefly review the link between PA, exercise, and aerobic fitness with mental well-being and reduced mental health problems in adolescence. Then we present how impairments in self-regulation, which involves top-down control to modulate bottom-up processes, are common across a wide range of mental health disorders. Finally, we use the extant neuroimaging literature to highlight how neural systems underlying top-down control continue to develop across adolescence, and propose that PA, exercise, and aerobic fitness may facilitate resilience through strengthening individual brain regions as well as large-scale neural circuits to improve emotional and behavioral regulation. Future neuroimaging studies assessing the effects of PA, exercise, and aerobic fitness at various developmental stages in each sex and studies considering the characteristics (e.g., frequency, intensity, type) and social context of PA and exercise are vital to better understand both macro- and microscale mechanisms by which these behaviors and attributes may facilitate mental health resilience during adolescent development.

Towards an integrated account of the development of self-regulation from a neurocognitive perspective: A framework for current and future longitudinal multi-modal investigations

Self-regulation is the ability to monitor and modulate emotions, behaviour, and cognition in order to adapt to changing circumstances. Developing adequate self-regulation is associated with better social coping and higher educational achievement later in life; poor self-regulation has been linked to a variety of detrimental developmental outcomes. Here, we focus on the development of neurocognitive processes essential for self-regulation. We outline a conceptual framework emphasizing that this is inherently an integrated, dynamic process involving interactions between brain maturation, child characteristics (genetic makeup, temperament, and pre- and perinatal factors) and environmental factors (family characteristics, parents and siblings, peers, and broader societal influences including media development). We introduce the Consortium of Individual Development (CID), which combines a series of integrated large-scale, multi-modal, longitudinal studies to take essential steps towards the ultimate goal of understanding and supporting this process.

Reinforcement Learning during Adolescence in Rats

The most dynamic period of postnatal brain development occurs during adolescence, the period between childhood and adulthood. Neuroimaging studies have observed morphologic and functional changes during adolescence, and it is believed that these changes serve to improve the functions of circuits that underlie decision-making. Direct evidence in support of this hypothesis, however, has been limited because most preclinical decision-making paradigms are not readily translated to humans. Here, we developed a reversal-learning protocol for the rapid assessment of adaptive choice behavior in dynamic environments in rats as young as postnatal day 30. A computational framework was used to elucidate the reinforcement-learning mechanisms that change in adolescence and into adulthood. Using a cross-sectional and longitudinal design, we provide the first evidence that value-based choice behavior in a reversal-learning task improves during adolescence in male and female Long-Evans rats and demonstrate that the increase in reversal performance is due to alterations in value updating for positive outcomes. Furthermore, we report that reversal-learning trajectories in adolescence reliably predicted reversal performance in adulthood. This novel behavioral protocol provides a unique platform for conducting biological and systems-level analyses of the neurodevelopmental mechanisms of decision-making.SIGNIFICANCE STATEMENT The neurodevelopmental adaptations that occur during adolescence are hypothesized to underlie age-related improvements in decision-making, but evidence to support this hypothesis has been limited. Here, we describe a novel behavioral protocol for rapidly assessing adaptive choice behavior in adolescent rats with a reversal-learning paradigm. Using a computational approach, we demonstrate that age-related changes in reversal-learning performance in male and female Long-Evans rats are linked to specific reinforcement-learning mechanisms and are predictive of reversal-learning performance in adulthood. Our behavioral protocol provides a unique platform for elucidating key components of adolescent brain function.

Liver disease in the young adult: the challenges and rewards

Increasing numbers of children are surviving into adulthood with a diagnosis of liver disease or having undergone liver transplantation. This population presents some challenges for the adult hepatologist, and a formal transition service clearly improves outcomes for patients in this group. Evidence of ongoing neurological development in young people up to the age of 25 years exists, and understanding these physiological processes is important in overcoming some of the challenges that caring for this population presents. A well designed transition service is key to maximising potential for these patients, and should enable young people to take control of their illness and achieve their life goals.

Effects of age and sex on clinical high-risk for psychosis in the community

BACKGROUND

Recent reports of both heightened prevalence rates and limited clinical relevance of clinical high-risk (CHR) criteria and their relevant symptoms in children and adolescents indicate an important role of neurodevelopment in the early detection of psychoses. Furthermore, sex effects in CHR symptoms have been reported, though studies were inconclusive. As sex also impacts on neurodevelopment, we expected that sex might have an additional contribution to age in the prevalence and clinical relevance of CHR symptoms and criteria.

AIM

To investigate age and sex effects on CHR criteria and symptoms and their association with psychosocial impairment and mental disorder.

METHODS

In this cross-sectional cohort study, n = 2916 8- to 40-year-olds, randomly drawn from the population register of the Swiss canton Bern, were assessed in semi-structured interviews by phone or face-to-face for CHR symptoms and criteria using the Structured Interview for Psychosis-Risk Syndromes and the Schizophrenia Proneness Instrument in its child and youth, and adult version, respectively. Furthermore, social and occupational functioning and DSM-IV axis I disorders were assessed. Simple and interaction effects of age and sex on CHR symptoms and criteria, and interaction effects of age, sex, and CHR symptoms and criteria on presentation of functional impairment and of non-psychotic disorder were investigated using logistic regression analyses.

RESULTS

Altogether, 542 (18.6%) participants reported any CHR symptom; of these, 261 (9.0%) participants reported any one of the 11 criteria relevant cognitive and perceptual basic symptoms, and 381 (13.1%) any one of the five attenuated or transient psychotic symptoms (attenuated psychotic symptoms/brief intermittent psychotic symptoms). Fewer participants met any one of the CHR criteria (n = 82, 2.8%) or any one of the three recently recommended CHR criteria (n = 38, 1.3%). Both age and sex were significantly (P < 0.05) associated with CHR symptoms and criteria, mostly by younger age and female sex. Though slightly differing between symptom groups, age thresholds were detected around the turn from adolescence to adulthood; they were highest for cognitive basic symptoms and CHR criteria. With the exception of the infrequent speech disorganization attenuated psychotic symptom, the interaction of age with CHR symptoms and criteria predicted functional impairment; whereas, independent of each other, sex and CHR symptoms mostly predicted mental disorders.

CONCLUSION

Age and sex differentially impact on CHR symptoms and criteria; these differences may support better understanding of causal pathways. Thus, future CHR studies should consider effects of sex and age.

Behavioral development in children with prenatal substance exposure and neonatal abstinence syndrome: Associated factors and implications

PROBLEM

Prenatal substance exposure and neonatal abstinence syndrome (NAS) are risk factors for adverse behavioral outcomes in children at 24 months of age.

METHODS

The purpose of this study was to examine factors associated with abnormal behavioral development in children with prenatal substance exposure or NAS through 10 years of age. A retrospective, nonexperimental, longitudinal design to examine the effects of prenatal substance exposure and NAS on behavioral development at 1, 5, and 10 years of age, while controlling for intrapersonal, interpersonal, community, organizational, and public policy characteristics. A hierarchical multivariate logistic regression model was used to evaluate the influence of substance exposure and NAS on behavioral outcomes.

FINDINGS

Abnormal behavioral development was predicted at 10 years of age with polysubstance exposure to three substances (odds ratio [OR] = 2.711, p < 0.01) and NAS (OR = 2.077, p < .001).

CONCLUSION

Psychiatric nursing care for children with prenatal substance exposure and NAS should include implementation of early and continued behavioral evaluation and childhood trauma and adversity surveillance in children through middle childhood.

Sex differences in the effects of gonadal hormones on white matter microstructure development in adolescence

Adolescence is characterized by rapid brain development in white matter (WM) that is attributed in part to surges in gonadal hormones. To date, however, there have been few longitudinal investigations relating changes in gonadal hormones and WM development in adolescents. We acquired diffusion-weighted MRI to estimate mean fractional anisotropy (FA) from 10 WM tracts and salivary testosterone from 51 females and 29 males (ages 9-14 years) who were matched on pubertal stage and followed, on average, for 2 years. We tested whether interactions between sex and changes in testosterone levels significantly explained changes in FA. We found positive associations between changes in testosterone and changes in FA within the corpus callosum, cingulum cingulate, and corticospinal tract in females (all ps<0.05, corrected) and non-significant associations in males. We also collected salivary estradiol from females and found that increases in estradiol were associated with increases in FA in the left uncinate fasciculus (p = 0.04, uncorrected); however, this effect was no longer significant after accounting for changes in testosterone. Our findings indicate there are sex differences in how changes in testosterone relate to changes in WM microstructure of tracts that support impulse control and emotion regulation across the pubertal transition.

Impact of b-value on estimates of apparent fibre density

Recent advances in diffusion magnetic resonance imaging (dMRI) analysis techniques have improved our understanding of fibre‐specific variations in white matter microstructure. Increasingly, studies are adopting multi‐shell dMRI acquisitions to improve the robustness of dMRI‐based inferences. However, the impact of b‐value choice on the estimation of dMRI measures such as apparent fibre density (AFD) derived from spherical deconvolution is not known. Here, we investigate the impact of b‐value sampling scheme on estimates of AFD. First, we performed simulations to assess the correspondence between AFD and simulated intra‐axonal signal fraction across multiple b‐value sampling schemes. We then studied the impact of sampling scheme on the relationship between AFD and age in a developmental population (n = 78) aged 8–18 (mean = 12.4, SD = 2.9 years) using hierarchical clustering and whole brain fixel‐based analyses. Multi‐shell dMRI data were collected at 3.0T using ultra‐strong gradients (300 mT/m), using 6 diffusion‐weighted shells ranging from b = 0 to 6,000 s/mm². Simulations revealed that the correspondence between estimated AFD and simulated intra‐axonal signal fraction was improved with high b‐value shells due to increased suppression of the extra‐axonal signal. These results were supported by in vivo data, as sensitivity to developmental age‐relationships was improved with increasing b‐value (b = 6,000 s/mm², median R² = .34; b = 4,000 s/mm², median R² = .29; b = 2,400 s/mm², median R² = .21; b = 1,200 s/mm², median R² = .17) in a tract‐specific fashion. Overall, estimates of AFD and age‐related microstructural development were better characterised at high diffusion‐weightings due to improved correspondence with intra‐axonal properties.

The Effectiveness of Progressive and Traditional Coaching Strategies to Improve Sprint and Jump Performance Across Varying Levels of Maturation within a General Youth Population

Literature pertaining to youth development has identified the importance of understanding the physical, intellectual and emotional needs of adolescents prior to, during, and after their peak height velocity (PHV) period. The purpose of this study was to compare the use of a ‘traditional’ and ‘progressive’ coaching style to train a general male youth population to improve sprint and jump performances whilst assessing enjoyment to comment on long-term application. Maximal sprint times, sprint kinematics, unilateral jump distances and repetitive tuck jump scores were measured alongside anthropometric variables to characterise performance. The results revealed significant (p < 0.05) pre/post differences in anthropometric variables across all maturation groups, and each of the maturational levels displayed a tendency to favor a particular coaching or control condition. Pre-PHV groups responded most effectively to the progressive style of coaching, displaying improvements in horizontal jump performances, and −0.7% to −2.7% improvements in all sprint times, despite also showing the largest increase in tuck jump scores (25.8%). The circa-PHV group produced their greatest improvements in the traditional intervention, as displayed through significant improvements (p < 0.05) in 20-m sprint times and dominant-leg horizontal jump performance, whilst also revealing the greatest deterioration in tuck jump scores (14.2%). Post-PHV displayed the greatest improvements in the control setting, suggesting that the natural benefits gained through adolescent development were greater than the influence of the training interventions. In conclusion, the results suggest that matching coaching strategies and delivery techniques to the period of biological maturation may have implications for both performance and athlete safety.

Effect of Parenting and Peer Stressors on Cognitive Vulnerability and Risk for Depression among Youth

Parenting behaviors influence clinical depression among youth, but little is known about the developmental processes that may account for this association. This study investigated whether parenting is associated with the onset of clinical depression and depressive symptoms through negative cognitive style, particularly under conditions of high exposure to stressors, in a community sample of children and adolescents (N = 275; 59% girls). Observational methods were used to assess positive and negative parenting during a laboratory social-evaluative stressor task. Depressive symptoms and clinical depressive episodes were repeatedly assessed over an 18-month prospective follow-up period. Results supported a conditional indirect effect in which low levels of observed positive parenting during a youth stressor task were indirectly associated with an increased likelihood of experiencing an episode of depression and worsening depressive symptoms over the course of the study through youth negative cognitive style, but only for youth who also experienced a high number of peer stressors. These findings elucidate mechanisms through which problematic parenting may contribute to risk for the development of clinical depression during the transition into and across adolescence. Implications for depression interventions are discussed.

Amygdalar reactivity is associated with prefrontal cortical thickness in a large population-based sample of adolescents

In structural neuroimaging studies, reduced cerebral cortical thickness in orbital and ventromedial prefrontal regions is frequently interpreted as reflecting an impaired ability to downregulate neuronal activity in the amygdalae. Unfortunately, little research has been conducted in order to test this conjecture. We examine the extent to which amygdalar reactivity is associated with cortical thickness in a population-based sample of adolescents. Data were obtained from the IMAGEN study, which includes 2,223 adolescents. While undergoing functional neuroimaging, participants passively viewed video clips of a face that started from a neutral expression and progressively turned angry, or, instead, turned to a second neutral expression. Left and right amygdala ROIs were used to extract mean BOLD signal change for the angry minus neutral face contrast for all subjects. T1-weighted images were processed through the CIVET pipeline (version 2.1.0). In variable-centered analyses, local cortical thickness was regressed against amygdalar reactivity using first and second-order linear models. In a follow-up person-centered analysis, we defined a “high reactive” group of participants based on mean amygdalar BOLD signal change for the angry minus neutral face contrast. Between-group differences in cortical thickness were examined (“high reactive” versus all other participants). A significant association was revealed between the continuous measure of amygdalar reactivity and bilateral ventromedial prefrontal cortical thickness in a second-order linear model (p < 0.05, corrected). The “high reactive” group, in comparison to all other participants, possessed reduced cortical thickness in bilateral orbital and ventromedial prefrontal cortices, bilateral anterior temporal cortices, left caudal middle temporal gyrus, and the left inferior and middle frontal gyri (p < 0.05, corrected). Results are consistent with non-human primate studies, and provide empirical support for an association between reduced prefrontal cortical thickness and amygdalar reactivity. Future research will likely benefit from investigating the degree to which psychopathology qualifies relations between prefrontal cortical structure and amygdalar reactivity.

Population-neuroscience study of the Tokyo TEEN Cohort (pn-TTC): Cohort longitudinal study to explore the neurobiological substrates of adolescent psychological and behavioral development

AIM

Adolescence is a crucial stage of psychological development and is critically vulnerable to the onset of psychopathology. Our understanding of how the maturation of endocrine, epigenetics, and brain circuit may underlie psychological development in adolescence, however, has not been integrated. Here, we introduce our research project, the population-neuroscience study of the Tokyo TEEN Cohort (pn-TTC), a longitudinal study to explore the neurobiological substrates of development during adolescence.

METHODS

Participants in the first wave of the pn-TTC (pn-TTC-1) study were recruited from those of the TTC study, a large-scale epidemiological survey in which 3171 parent-adolescent pairs were recruited from the general population. Participants underwent psychological, cognitive, sociological, and physical assessment. Moreover, adolescents and their parents underwent magnetic resonance imaging (MRI; structural MRI, resting-state functional MRI, and magnetic resonance spectroscopy), and adolescents provided saliva samples for hormone analysis and for DNA analysis including epigenetics. Furthermore, the second wave (pn-TTC-2) followed similar methods as in the first wave.

RESULTS

A total of 301 parent-adolescent pairs participated in the pn-TTC-1 study. Moreover, 281 adolescents participated in the pn-TTC-2 study, 238 of whom were recruited from the pn-TTC-1 sample. The instruction for data request is available at: http://value.umin.jp/data-resource.html.

CONCLUSION

The pn-TTC project is a large-scale and population-neuroscience-based survey with a plan of longitudinal biennial follow up. Through this approach we seek to elucidate adolescent developmental mechanisms according to biopsychosocial models. This current biomarker research project, using minimally biased samples recruited from the general population, has the potential to expand the new research field of population neuroscience.

Puberty and the Evolution of Developmental Science

In recent decades, theoretical and methodological advances have operated synergistically to advance understanding of puberty and prompt increasingly comprehensive models that engage with the temporal, psychosocial, and biological dimensions of this maturational milepost. This integrative overview discusses these theoretical and methodological advances and their implications for research and intervention to promote human development in the context of changing maturational schedules and massive ongoing social transformations.

Marijuana's Effects on Brain Structure and Function: What Do We Know and What Should We Do? A Brief Review and Commentary

The recent US Food and Drug Administration approval of the marijuana constituent cannabidiol as safe and effective for treatment of 2 rare forms of epilepsy has raised hopes that others of the 500 chemicals in marijuana will be found to be therapeutic. However, the long-term consequences of street marijuana use are unclear, and recent studies raise red flags about its effects. Changes in brain maturation and intellectual function, including decreases in intelligence quotient, have been noted in chronic users and appear permanent in early users in most but not all studies. These studies suggest that at a minimum, regular marijuana use should be discouraged in individuals under the age of 21.

Understanding the Role of Puberty in Structural and Functional Development of the Adolescent Brain

Over the past two decades, there has been a tremendous increase in our understanding of structural and functional brain development in adolescence. However, understanding the role of puberty in this process has received much less attention. This review examines this relationship by summarizing recent research studies where the role of puberty was investigated in relation to brain structure, connectivity, and task-related functional magnetic resonance imaging (fMRI). The studies together suggest that puberty may contribute to adolescent neural reorganization and maturational advancement, and sex differences also emerge in puberty. The current body of work shows some mixed results regarding impact and exact direction of pubertal influence. We discuss several limitations of current studies and propose future directions on how to move the field forward.

Next Steps in Puberty Research: Broadening the Lens Toward Understudied Populations

Decades of puberty research have yielded key scientific discoveries. Building on the field's rich history, we highlight four understudied populations: youth of color, boys, sexual minority youth, and gender minority youth. We explore why scientific study has been slow to evolve in these groups and propose paths forward for exciting new work. For ethnically racially diverse youth, we discuss the need to incorporate culture and context. For boys, we highlight methodological issues and challenges of mapping existing conceptual models onto boys. For sexual and gender minority youth, we discuss unique challenges during puberty and suggest ways to better capture their experiences. With an eye toward a new era, we make recommendations for next steps and underscore the importance of transdisciplinary research.

Pregnancy and adolescence entail similar neuroanatomical adaptations: A comparative analysis of cerebral morphometric changes

Mapping the impact of pregnancy on the human brain is essential for understanding the neurobiology of maternal caregiving. Recently, we found that pregnancy leads to a long-lasting reduction in cerebral gray matter volume. However, the morphometric features behind the volumetric reductions remain unexplored. Furthermore, the similarity between these reductions and those occurring during adolescence, another hormonally similar transitional period of life, still needs to be investigated. Here, we used surface-based methods to analyze the longitudinal magnetic resonance imaging data of a group of 25 first-time mothers (before and after pregnancy) and compare them to those of a group of 25 female adolescents (during 2 years of pubertal development). For both first-time mothers and adolescent girls, a monthly rate of volumetric reductions of 0.09 mm³ was observed. In both cases, these reductions were accompanied by decreases in cortical thickness, surface area, local gyrification index, sulcal depth, and sulcal length, as well as increases in sulcal width. In fact, the changes associated with pregnancy did not differ from those that characterize the transition during adolescence in any of these measures. Our findings are consistent with the notion that the brain morphometric changes associated with pregnancy and adolescence reflect similar hormonally primed biological processes.

Sex differences of brain and their implications for personalized therapy

Nowadays, it is known that the sex differences regard many organs, e.g., liver, vessels, pancreas, lungs, bronchi and also the brain. Sex differences are not just a matter of ethical and moral principles, as they are central to explain many still unknown diseases and their understanding is a prerequisite to develop an effective therapy for each individual. This review reports on those sex differences that are not only macroscopic and morphological, but also involve molecular and functional dimorphism in the brain. It will recapitulate the main structural differences between male and female brain including the neurotransmission systems; in particular, the main objective is to identify a correlation, already known or to be investigated in the future, between the differences that characterize male and female brains from a morphological and biochemical point of view and neurological syndromes. This correlation could provide a starting point for future scientific research aimed to investigate and define a personalized therapy.

Associations between Child Maltreatment, Harsh Parenting, and Sleep with Adolescent Mental Health

Youth who suffer from psychiatric disorders are at high risk for negative outcomes, including aggression and substance abuse. Although many youth with psychiatric disorders have endured harsh parenting and/or child maltreatment (CM), differential associations between these experiential factors have yet to be fully explored. Sleep problems have also been implicated in psychiatric disorders and are consistently associated with CM. The overlap and unique contributions of CM and sleep problems to the mental health of youth remains unclear; longitudinal studies from late childhood into adolescence, when psychiatric illnesses frequently onset, are rare. The current longitudinal study examined associations of CM, harsh parenting, and sleep problems with symptoms of four psychiatric disorders: Conduct Disorder, Attention Deficit Hyperactivity Disorder, Anxiety, and Depression. Early adolescent youth with no history of substance use (N = 529) were sampled from a working class, medium-sized city in northern Kentucky, and an extensive battery of tests were administered to youth and a parent. CM was more strongly and consistently related to psychiatric disorder symptoms at baseline than was harsh parenting. Reports of harsh parenting were more strongly associated with externalizing symptoms than internalizing symptoms. Sleep problems were also positively associated with psychiatric disorder symptoms at baseline, but did not exacerbate the effects of CM or harsh parenting on symptom counts. Longitudinally, harsh parenting was more predictive of change in psychiatric symptoms two to three years later than was CM. The potential significance of childhood adversity and sleep problems for prevention of later mental health problems are discussed.

Understanding Emotion in Adolescents: A Review of Emotional Frequency, Intensity, Instability, and Clarity

Adolescence is a time of transition from childhood to adulthood during which significant changes occur across multiple domains, including emotional experience. This article reviews the relevant literature on adolescents’ experience of four specific dimensions of emotion: emotional frequency, intensity, instability, and clarity. In an effort to examine how emotional experiences change as individuals approach adulthood, we examine these dimensions across ages 10 to 19, and review how the emotional functioning of adolescents compares to that of adults. In addition, we explore whether and how gender and puberty explain age differences in emotional experience. Finally, we discuss how these findings could inform future research on both the typical trajectory of emotional experience and the development of psychopathology in adolescence.

Girls' pubertal development is associated with white matter microstructure in late adolescence

Patterns of pubertal maturation have been linked to vulnerability for emotion dysregulation disorders in girls, as well as white matter (WM) development, suggestive of a potential mechanism between pubertal maturation and emotional health. Because pubertal processes begin at varying ages (i.e., status, timing) and proceed at varying rates (i.e., tempo), identifying individual differences in the pubertal course associated with subsequent WM microstructure development may reveal clues about neurobiological mechanisms of girls' emotional well-being. In a prospective cohort study of 107 girls, we examined associations between pubertal status at age 9, pubertal timing and tempo from ages 9-15, and WM microstructure at age 19. Tract-based spatial statistics revealed that girls with more advanced pubertal status at age 9, specific to gonadal-related physical changes, had higher fractional anisotropy, and lower mean diffusivity (MD) and radial diffusivity in tracts relevant to cognitive control and emotion regulation (e.g., the superior longitudinal fasciculus, external capsule, and uncinate fasciculus). Additionally, girls with earlier pubertal timing showed lower MD in the left anterior cingulum bundle. Tempo was unrelated to WM measures. These findings implicate specific aspects of pubertal maturation in subsequent neural signatures, suggesting possible neuroendocrine mechanisms relevant to emotional development. Future work incorporating longitudinal neuroimaging in parallel with pubertal measures may contribute to the understanding of individual variation in pubertal course and WM development.

Network specialization during adolescence: Hippocampal effective connectivity in boys and girls

Adolescence is a complex period of concurrent mental and physical development that facilitates adult functioning at multiple levels. Despite the growing number of neuroimaging studies of cognitive development in adolescence focusing on regional activation patterns, there remains a paucity of information about the functional interactions across these participating regions that are critical for cognitive functioning, including memory. The current study used structural equation modeling (SEM) to determine how interactions among brain regions critical for memory change over the course of adolescence. We obtained functional MRI in 77 individuals aged 8-16 years old, divided into younger (ages 8-10) and older (ages > 11) cohorts, using an incidental encoding memory task to activate hippocampus formation and associated brain networks, as well as behavioral data on memory function. SEM was performed on the imaging data for four groups (younger girls, younger boys, older girls, and older boys) that were subsequently compared using a stacked model approach. Significant differences were seen between the models for these groups. Younger boys had a predominantly posterior distribution of connections originating in primary visual regions and terminating on multi-modal processing regions. In older boys, there was a relatively greater anterior connection distribution, with increased effective connectivity within association and multi-modal processing regions. Connection patterns in younger girls were similar to those of older boys, with a generally anterior-posterior distributed network among sensory, multi-modal, and limbic regions. In contrast, connections in older girls were widely distributed but relatively weaker. Memory performance increased with age, without a significant difference between the sexes. These findings suggest a progressive reorganization among brain regions, with a commensurate increase in efficiency of cognitive functioning, from younger to older individuals in both girls and boys, providing insight into the age- and gender-specific processes at play during this critical transition period.

Media use and brain development during adolescence

The current generation of adolescents grows up in a media-saturated world. However, it is unclear how media influences the maturational trajectories of brain regions involved in social interactions. Here we review the neural development in adolescence and show how neuroscience can provide a deeper understanding of developmental sensitivities related to adolescents' media use. We argue that adolescents are highly sensitive to acceptance and rejection through social media, and that their heightened emotional sensitivity and protracted development of reflective processing and cognitive control may make them specifically reactive to emotion-arousing media. This review illustrates how neuroscience may help understand the mutual influence of media and peers on adolescents' well-being and opinion formation.