Journal of Child Psychology and Psychiatry

Cognitive function, psychological processes, mental states, and behaviors are key dimensions of human subjective experience that separately relate to mental disorders across diagnostic categories. However, whether these dimensions are linked to common or distinct brain morphological patterns that convey risk or resilience for psychiatric disorders remains unclear. The current study is a longitudinal investigation on 11,875 youths from the Adolescent Brain Cognitive Development (ABCD) Study aged 9-10 years at baseline. A machine learning approach based on canonical correlation analysis was used to identify latent dimensional associations of cortical morphology (4 metrics: surface area, cortical and subcortical volume, cortical thickness, and sulcal/gyral depth) with multidomain behavioral assessments including cognitive scores and psychological measures indexing motivation, impulse control, mental states, and behaviors across a normative continuum from healthy to pathological. Across morphological measures, we identified a robust latent brain structural variate that correlated positively with cognitive performance and negatively with psychological measures indexing greater psychology. Notably, higher scores on this brain variate reflected larger cortical surface area and cortical volume--especially in the temporal gyri--together with a posterior-anterior gradient in cortical thickness, showing relatively greater thickness in occipital, parietal, and temporal cortices and lower thickness in cingulate and frontal regions. This brain variate and the related cognitive-psychological-behavioral variate remained stable at the 2-year follow-up, demonstrating temporal consistency. Importantly, the brain variate showed a dose-dependent relationship with the cumulative number of psychiatric diagnoses assessed concurrently and at 2-year follow-up, with lower brain variate scores being associated with higher numbers of comorbid diagnoses. In addition, the brain scores were associated with longitudinal transitions between healthy and diagnosed states over the 2-year study period, in which lower scores at baseline were associated with persistent psychiatric diagnoses whereas higher scores at baseline were associated with persistent healthy states, suggesting that the brain scores capture a vulnerability- resilience continuum for psychopathology. By revealing shared brain structural substrates across conventional diagnostic boundaries, these findings advance the neurodevelopmental understanding of psychiatric disorders and highlight the potential utility of morphology-informed approaches for early screening and intervention in youth.

BackgroundParental genetics matters for childrens behavioural difficulties, but the extent to which this is due to direct genetic transmission versus environmentally mediated indirect genetic effects remains unclear. MethodsWe studied eight European birth cohorts with over 33,000 family-based trio samples. We analysed polygenic scores (PGSs) for 13 mental health and neurodevelopmental conditions and their composite indices (PC1 and mean) representing general neuropsychiatric liabilities, as well as educational attainment (EA) and alcohol and cigarette use, from children (PGSc), mothers (PGSm), and fathers. Child internalising, externalising, and total difficulties reported by mothers and/or fathers were examined at preschool and school ages. We then conducted multivariate meta-analyses to combine cohort-level results. FindingsWe observed several direct genetic effects on externalising difficulties, while indirect genetic influences were mainly identified for internalising difficulties. Specifically, child PGSs for attention-deficit/hyperactivity disorder (ADHD) and EA predicted higher and lower levels, respectively, of child externalising and total difficulties (all pFDR<0{middle dot}001; for school-aged externalising difficulties, PGSc-ADHD: {beta}=0{middle dot}121 [95% CI 0{middle dot}091 to 0{middle dot}151], pFDR<0{middle dot}0001; PGSc-EA: {beta}=-0{middle dot}095 [95% CI -0{middle dot}127 to -0{middle dot}063], pFDR<0{middle dot}0001), whereas maternal PGSs for major depressive disorder (MDD) and general neuropsychiatric liabilities were associated with internalising and total difficulties across parental raters and child ages (all pFDR<0{middle dot}05; for school-aged internalising difficulties, PGSm-MDD: {beta}=0{middle dot}049 [95% CI 0{middle dot}017 to 0{middle dot}081], pFDR=0{middle dot}016; PGSm-PC1: {beta}=0{middle dot}056 [95% CI 0{middle dot}022 to 0{middle dot}091], pFDR=0{middle dot}011). No statistically significant effects from paternal PGSs were identified. InterpretationIn this multi-cohort study, findings across multiple traits, raters, and ages supported several direct genetic effects of ADHD and EA on child externalising difficulties and indirect genetic effects on internalising difficulties, especially maternal depression and general neuropsychiatric liabilities. These suggest that child internalising difficulties are not solely driven by direct genetic transmission. More comprehensive research is needed to better understand the mechanisms involved, and ultimately how to ameliorate child behavioural difficulties. FundingEU, ERC, RCN, RCF, UKRI, SERI, DFG Research in contextO_ST_ABSEvidence before this studyC_ST_ABSIndirect genetic effects (IGEs) refer to the influence of parental genotypes on offspring outcomes beyond direct genetic effects (DGEs), for example via environmental pathways. While IGEs on offspring cognitive traits are well-established for educational attainment, evidence for IGEs of parental liabilities to mental health and neurodevelopmental conditions remains limited. To assess the current state of evidence, we conducted a systematic search of published studies applying trio-based polygenic score (PGS) designs to child and adolescent mental health outcomes. We identified 141 primary studies in MEDLINE, Embase, PsycInfo, and Web of Science, by 6 March 2025, after removing duplicates; following screening, 12 studies met inclusion criteria (see supplement for a full description including results). Ten out of the 12 studies focused on externalising outcomes, with little or inconsistent support for IGEs. When observed, IGEs were mainly driven by maternal liabilities to autism, educational attainment, and cognitive performance on child outcomes. The current evidence was too limited and heterogeneous to synthesize findings quantitatively, therefore a qualitative synthesis was conducted. Many studies were statistically underpowered, and the observed IGEs were in all cases sample-specific. There were no published multi-cohort studies. Added value of this studyWe integrated information across over 33,000 mother-father-child trios from eight European cohorts, investigating 18 PGSs from parents and children, using maternal and paternal ratings of offsprings internalising, externalising, and total difficulties as outcomes at both preschool and school age. We mainly observed DGEs on externalising difficulties, consistent with previous studies. Some evidence of IGEs was found for internalising and total difficulties. IGEs were often found to be maternally driven, with the most robust evidence across ages and raters emerging for maternal depression and general neuropsychiatric liabilities. Implications of all the available evidenceThe current evidence suggests that childrens behavioural difficulties, especially internalising difficulties, may be partly driven by the environment shaped by maternal neuropsychiatric liabilities. Ours and previous findings highlight a pressing need for more comprehensive studies across different cohorts, raters, outcomes, and time points to understand the true extent of IGEs in the intergenerational transmission of mental health.

Atypical social functioning is a core feature of autism, yet findings remain fragmented across components and development. We aimed to systematically integrate this literature and characterize the organization, development, and moderators of social functioning in autism. We conducted a systematic review and meta-analysis of behavioral studies published between January 1990 and August 2025, identified through PubMed, Web of Science, and prior reviews, including studies with clinically diagnosed autistic individuals and neurotypical controls. A qualitative synthesis and two complementary quantitative meta-analyses were performed, with risk of bias evaluated through study-level characteristics. A total of 2,622 studies (94,114 autistic and 172,847 neurotypical individuals across 32 countries) were included, covering 22 social components that clustered into five domains. Overall group differences were substantial (Hedges g = -0.744, 95% CI [-0.797, -0.690]). Differences emerged earliest in motivation-based processes ([~]6 months), followed by motor, emotion, and inference domains, and showed age-related divergence alongside improvement in some skills. Cross-domain analyses revealed stronger interdependencies in autism and an organizational pattern most consistent with serial relationships among domains. These findings should be interpreted in light of methodological heterogeneity, underpowered samples, and uneven cultural representation. Together, the results provide an integrative framework for understanding the organization and development of social functioning in autism, with implications for precision subtyping, developmentally timed interventions, and neurodiversity-informed research and policy. This study was pre-registered (PROSPERO: CRD42024566141).

Objective: While ADHD symptoms often decline from childhood into adulthood, the underlying neurobiological mechanisms, such as altered brain maturation or neural reorganization, remain incompletely understood. This study investigated how grey matter development relates to ADHD symptom trajectories into adulthood. Method: We analyzed data of individuals with ADHD and controls from the longitudinal Dutch NeuroIMAGE cohort, utilizing dimensional ADHD symptom scores (Conners Parent Rating Scale) from three waves and T1-weighted structural MRI scans from the final two waves. Using General Linear Models with permutation-based inference, we examined: 1) cross-sectional associations between ADHD symptoms and vertex-wise cortical thickness and surface area, and subcortical volumes at Wave 1 (n = 765, mean age = 16.95 years); and 2) longitudinal associations between symptom progression and brain morphometric changes (Wave 0 to 1: n = 644, mean age = 11.55-17.24 years; Wave 1 to 2: n = 149, mean age = 16.45-20.11 years). Results: Cross-sectionally, at Wave 1, more ADHD symptoms were related to widespread reductions in surface area, most prominently in the frontal cortex, and smaller volumes of the cerebellum, amygdala, and hippocampus. Longitudinally, symptom improvement from Wave 1 to Wave 2 was associated with stronger reductions in surface area, particularly in prefrontal and occipital regions, and with more pronounced cortical thinning across multiple brain regions. Conclusion: These findings suggest an association between symptom trajectories and structural brain changes, indicating that clinical improvement in ADHD behaviors might coincide with ongoing neural refinement during the transition to adulthood.

Background: Early adolescence is a common period of onset for depressive symptoms. In part, this may reflect a developmental manifestation of individual's genetic propensities as they undergo physiological and hormonal changes and interact with new environments. Many commonly proposed mechanisms assume direct effects of an individual's own genes on emerging variation in their depressive symptomatology. However, estimates of genetic influence based on analyses in unrelated individuals capture not only direct genetic effects but also genetic effects from parents and other biologically related family members. Aim: In data from the Norwegian Mother, Father and Child Cohort (MoBa), we used linear mixed models to distinguish developmentally-stable and adolescence-specific direct and parental indirect genetic effects. We examined effects of polygenic scores for major depressive disorder (MDD), ADHD, anxiety disorders, and educational attainment (EA) on depressive symptoms, which were assessed by maternal reports at ages 8 and 14. Results: Children's own MDD polygenic scores showed adolescence-specific effects on depressive symptoms ( b_PGS*wave=0.041, [95% CI: 0.017, 0.065]). Developmentally-stable direct effects from children's polygenic scores for MDD (b=0.016, [0.006, 0.039]), ADHD (b=0.024, [0.008, 0.041]) and EA (b=-0.02, [ -0.038, -0.002]) were also evident. The only evidence of indirect genetic effects was a stable effect of maternal EA polygenic scores (b=0.04, [0.024, 0.054]). Conclusion: Direct genetic effects linked to genetic liability to MDD accounted for emerging variation in depressive symptoms in adolescence. These results imply that specific etiological mechanisms related to MDD may become particularly relevant for depressive symptoms during early adolescence compared to at earlier ages.

Understanding depressive symptoms dynamics and their determinants is crucial for designing effective mental health support initiatives. This study compared two methods for describing youth depressive symptoms trajectories and investigated associations of early-life factors (maternal education, maternal perinatal depression, domestic violence, physical, emotional, or sexual abuse, bullying victimisation, psychiatric disorder) with trajectory features. Prospective data from 8,264 mostly White European participants (54% female), including self-reported Short Moods and Feelings Questionnaires on ten occasions between 10-25 years, were used. Trajectories were summarised using functional principal component analysis (FPCA) and P-splines linear mixed-effect (PLME) models. Estimated derivatives were used to obtain magnitude and age of peak symptoms and peak symptoms velocity. Both methods performed comparably, but PLME models tended to over-smooth trajectories. Peak symptoms and peak velocity were higher and occurred >1 year earlier in females than males. All early-life factors were associated with higher peak symptoms, and most associated with higher and earlier peak velocity. Abuse and bullying additionally associated with earlier age of peak symptoms. FPCA is a useful alternative for characterising depressive symptoms trajectories and informing time-sensitive preventative measures to reduce impact of depression before symptoms reach their peak. Early-life stressors may accelerate timeline and intensity of symptoms escalation during adolescence. Lay summaryUnderstanding development of depressive symptoms and factors shaping them is crucial for designing effective mental health support initiatives. This study used data from over 8,000 young people regularly followed up from before birth to compare two cutting-edge methods for describing depressive symptoms trajectories and examined how known risk factors for adulthood depression relate to the severity and rate of change of depressive symptoms in adolescence. We found that both methods performed well and that the peaks in depressive symptoms and their rate of change were, on average, higher and occurred over a year earlier in females than males. Our findings additionally suggest that early-life stressors (e.g., abuse, bullying) may accelerate the development of depression, highlighting the importance of early prevention.

Mind wandering has been linked to a wide range of psychiatric conditions, yet most studies have examined these associations in isolation. Given the substantial comorbidity across the psychopathological spectrum, it remains unclear whether elevated mind wandering reflects a general marker of psychopathology or a more specific attentional-control deficit shared across symptom dimensions. To address this, we adopted a dimensional, transdiagnostic approach in a non-clinical sample (N = 376), simultaneously modeling seven symptom dimensions: ADHD, depression, obsessive-compulsive tendencies, schizotypy, autistic traits, hypomania, and eating disorder symptoms. At the bivariate level, mind wandering correlated positively with all symptom dimensions. However, when the substantial shared variance across dimensions was accounted for in both frequentist and Bayesian multivariate regression models, only ADHD symptoms emerged as a unique predictor ({beta} = 0.53; BF{square}{square} > 1000), with all remaining predictors yielding negligible unique contributions and Bayes factors supporting the null hypothesis. These findings suggest that previously reported associations between mind wandering and diverse psychopathological symptom dimensions largely reflect a shared liability with ADHD-related attentional dysregulation, rather than disorder-specific mechanisms. This positions mind wandering as a marker of attentional dysregulation more closely tied to ADHD symptomatology than to general psychopathological burden.

BackgroundMaternal mental health is an important contributor to child neurodevelopment. While there are multiple studies on prenatal exposure, early postnatal exposure has received little attention in neuroimaging research. Methods5-year-old children (n = 173) were recruited from the FinnBrain Birth Cohort study. Maternal distress was assessed using questionnaires on depressive and anxiety symptoms at 14, 24 and 34 gestational weeks and postnatally at 3, 6 and 24 months. T1-weighted structural images were processed using a voxel-based morphometry pipeline to map associations between maternal distress exposure and regional gray matter (GM) volumes, while accounting for potential confounders. ResultsWe found widespread associations between maternal distress symptoms and offspring brain morphology. Higher prenatal distress at 14 gestational weeks was positively associated with regional GM volume in the right superior parietal lobe and precuneus. In contrast, postnatal distress at 3 months was negatively associated with GM volumes in multiple motor regions, the left anterior insula, right superior frontal areas and supramarginal gyrus. Postnatal distress at 6 months demonstrated a positive relationship with GM volumes in the right calcarine and lingual gyri, while distress at 24 months was negatively associated with GM volumes in the left supramarginal and right superior frontal gyri. ConclusionsThis study provides support for hypotheses proposing that fetal and early life exposure to maternal distress can influence the structural development of the brain. Furthermore, it highlights the role of early postnatal period and calls for further research into this so far overlooked period and pathways that explain the associations.

Children exposed to severe childhood maltreatment often develop complex mental health disorders where standard treatments show limited efficacy. Current residential approaches combine psychopharmacological with behavioural interventions, yet the feasibility and clinical-neurobiological outcomes of intensive, medication-free psychotherapy have not been investigated in this population. Our prospective study followed severely traumatized children (aged 6-13 years) with documented histories of changes and failures in placement.They completed an intensive 6-8 months inpatient treatment program (5 individual psychotherapy and 3 group therapy sessions per week with high caregiver-patient ratio) grounded in a novel, multimodal, attachment-based therapeutic framework. Medication was discontinued prior to treatment. The intervention group was compared to healthy controls and waitlist controls receiving treatment as usual. Participants in the intervention group achieved high remission rates for dysregulated behaviour (Child Behaviour Checklist (CBCL) >60% post treatment, 50% on follow-up) and trauma-related symptoms (Parent Report of Post-traumatic Stress Symptoms (PROPS) >65% post treatment, >60% on follow-up). Within-group effect sizes for Total Problems Score, Externalising behaviour (both CBCL), Hyperactivity (Strengths and Difficulties Questionnaire) and trauma symptoms (PROPS) each exceeded Cohen's d = 1.0 and were maintained at 6-month follow-up. Resting-state fMRI identified significant functional reorganization in visual processing networks. Atypical correlation patterns between visual network activity and symptom severity resolved following treatment, yielding patterns comparable to those of healthy controls. These pilot findings provide initial evidence of the feasibility and effectiveness of intensive, medication-free, attachment-based inpatient treatment to promote clinical remission and neurobiological normalization in severely traumatized children.

BackgroundEnriched environments support neurodevelopment. The pathways linking enrichment to cognitive processes such as episodic memory among youth remain unclear. This study examined whether brain function and structure in episodic memory-implicated neurocircuitry mediate the relationship between neighborhood enrichment and episodic memory performance. MethodsWe analyzed data from the Adolescent Brain Cognitive Development Study (n = 9,028) at two timepoints (baseline: 9-11-years-old and two-year follow-up: 11-13-years-old). Neighborhood enrichment was estimated at the childs primary residential address proxied by the Child Opportunity Index 2.0 (COI). Episodic memory was assessed using the Picture Sequence Memory Test (PSMT). A multimodal neuroimaging approach examined task-based working memory-related functional activity, brain volume, and resting-state intrinsic activity in 26 bilateral brain regions, segmented using the Desikan-Killiany atlas, implicated in episodic memory. Following FDR-corrected linear mixed effects models, controlling for sociodemographic, neuroimaging factors, and site-related variability, two sets of mediation analyses were conducted per time point. ResultsGreater neighborhood enrichment (i.e., higher COI scores) was directly associated with better episodic memory, prefrontal cortex (PFC) task-based functional activity, and larger PFC and medial temporal lobe volume across timepoints. PFC task-based functional activity, but not brain volume or intrinsic activity, partially mediated these relationships. Specifically, PFC task-activity in the left and right caudal and rostral middle frontal gyri, and left pars opercularis, accounted for [~]2-7% of the mediated effect. ConclusionOur findings contribute to a rapidly growing body of literature linking environmental influences on neurocognitive outcomes during development. Given childhood and adolescence represent sensitive periods for neurodevelopment, interventions aimed at increasing neighborhood access to enriching experiences such as educational opportunities, cognitively stimulating activities, and social support may have lasting benefits for neurocognitive development.

ImportancePrenatal cannabis exposure is increasing in prevalence, yet its associations with early brain development--particularly how the timing and frequency of exposure across gestation relate to neonatal brain structure--remain insufficiently understood. Clarifying these associations is essential for informing early risk identification and guiding perinatal care. ObjectiveTo examine associations between patterns of maternal prenatal cannabis exposure, including exposure presence, gestational timing, and frequency of exposure, and neonatal brain structure and microstructure during the first month of life. Design, Setting, and ParticipantsThis cohort study included 1,782 mother-infant dyads (221 with PCE) from the HEALthy Brain and Child Development Study. Mother-reported prenatal cannabis exposure was assessed using the validated Timeline Follow-back method. Infants underwent natural-sleep magnetic resonance imaging, including T2-weighted structural imaging and diffusion imaging, within the first month of life. Main Outcomes and MeasuresAssociations between prenatal cannabis exposure and regional T2-weighted volumes and diffusion white matter microstructure metrics examined (1) exposure presence, (2) gestational timing of exposure, and (3) frequency of exposure within exposed infants. ResultsAny prenatal cannabis exposure was associated with brain volume differences in cerebellar and subcortical limbic regions, including smaller amygdala, thalamic, and cerebellar vermis volumes and larger caudate, hippocampal, and cerebellar cortex volumes. Timing-specific analyses revealed divergent patterns: first trimester exposure was associated with smaller volumes in select regions, whereas exposure that continued into the third trimester was associated with larger volumes in overlapping structures, with additional subcortical volumetric differences observed. White matter microstructure alterations were observed only among infants with exposure that continued into the third trimester. Within the exposed subgroup, higher frequency of cannabis exposure was associated with larger cerebral white matter volumes and white matter microstructural differences in white matter regions. Conclusions and RelevanceIn infants with maternal prenatal cannabis exposure, we observed timing- and frequency-dependent differences in brain development within the first month of life. These findings underscore the importance of considering not only the presence of exposure, but also when and how much cannabis is used during pregnancy to support targeted prenatal counseling and early developmental monitoring for exposed infants. Key PointsO_ST_ABSQuestionC_ST_ABSIs prenatal cannabis exposure associated with brain development in the first month of life? FindingsIn a cohort[ABS] of 1,782 mother-infant dyads, prenatal cannabis exposure was associated with region-specific differences in neonatal brain volumes. Brain volume and diffusion white matter microstructure associations differed between exposure limited to the first trimester versus exposure that continued into the third trimester. Greater frequency of exposure across gestation was also associated with volumetric and microstructural differences. MeaningThe timing and frequency of prenatal cannabis exposure is associated with alterations in neonatal brain development, underscoring the importance of addressing cannabis use in pregnancy.

Background: Major depressive disorder (MDD) is the leading cause of non-fatal disability in youth and disproportionately affects adolescent females. Structural MRI studies of adolescent depression have yielded inconsistent findings, potentially reflecting symptom heterogeneity and rapid developmental changes in brain morphology. Methods: In this longitudinal study, we examined associations between specific depressive symptoms and structural brain MRI measures in 9,722 youth (53% male, age range = 10.0-17.7, 24,378 observations) from the Adolescent Brain Cognitive Development (ABCD) Study. A four-wave panel graphical vector autoregression (GVAR) model was estimated to separate within-person (contemporaneous and temporal networks) from stable between-person effects. Brain measures included cortical thickness in the insula, cingulate, medial orbitofrontal cortex (mOFC) and fusiform gyrus, as well as hippocampal volume. Depressive symptoms included parent-reported depressed mood, anhedonia, lethargy, and worthlessness. Additionally, sex-differences in network structures were tested. Results: Strong within-domain associations were observed among brain measures and among symptoms, with the largest effects in the symptom domain. Cross-domain (brain-symptom) associations emerged only at the within-person level, where elevated depressed mood was associated with contemporaneous and subsequent reductions in cingulate and fusiform gyrus thickness (partial r = [-0.02 - 0.04]). No cross-domain associations were detected in the between-person networks. Sex-differences emerged only in the within-person networks. Conclusions: Associations between brain structure and depressive symptoms were subtle, symptom-specific, and dynamic rather than reflecting stable individual differences. Longitudinal within-person approaches are therefore important for understanding neurodevelopmental contributions to adolescent depression risk.

Importance: Parent/caregiver-infant early relational health (ERH) is known to play a critical role in the promotion of socio-emotional functioning and wellbeing across the life course. The negative impact of the COVID-19 pandemic on maternal mental health and secondarily on ERH and child socio-emotional functioning is clear. However, the direct impact of maternal viral exposure during pregnancy on ERH has not been investigated. Objective: The goal of this study was to determine the impact of prenatal SARS-CoV-2 exposure on ERH and infant socio-emotional functioning in the first 6 months of life. Design: Mothers with and without SARS-CoV-2 exposure during pregnancy who gave birth from 02/2020 to 09/2021 were enrolled from 05/2020 to 09/2021 in one of two parallel prospective studies (the COVID-19 Mother Baby Outcomes [COMBO] Initiative or the Respiratory Syndrome Coronavirus 2 in Pregnancy and Infancy [ESPI] COMBO sub-study). Mothers reported on their health and the socio-emotional functioning of their infant via online surveys (REDCap) at enrollment, 1, 2, 4, and 6 months. At 4 to 6 months, dyads were invited to participate in a video-based, remote assessment of ERH. Participants: 884 mother-infant dyads from three U.S. States (Alabama, New York, and Utah). Exposure: Prenatal SARS-CoV-2. Main Outcomes and Measures: Maternal-reported ERH (parental stress, parenting confidence and bonding) and observer-based ERH (video-coded quality of maternal caregiving behaviors and mother-infant emotional connection). Infant socio-emotional development assessed using the 6-month Ages and Stages Questionnaire: Socio-Emotional 2nd Edition (ASQ:SE-2). Results: 316 (36%) mothers had a positive prenatal SARS-CoV-2 exposure. Prenatal SARS-CoV-2 exposure was associated with an adjusted estimate of ~5% reduction (incidence rate ratio=0.95, 95% confidence interval [0.90, 1.00], p=0.03) in observed maternal caregiving quality, after accounting for postnatal maternal mental health and sociodemographic factors. We found no evidence of effect on other ERH constructs or infant socio-emotional functioning. Conclusions and Relevance: In this large prospective cohort study, prenatal SARS-CoV-2 was associated with a small decrement in caregiving quality, but not other ERH constructs or infant socio-emotional functioning. These findings should be interpreted as hypothesis generating and will require replication in independent studies.

ImportanceEating disorders (EDs) are heritable, yet the developmental pathways through which genetic liability manifests in early life remain unclear. ObjectiveTo investigate the associations between genetic liability for anorexia nervosa (AN) and binge eating (BE) and disordered eating behaviors (DEB) across childhood, and to identify the mediating roles of metabolic and psychosocial traits. Design, Setting, and ParticipantsThis longitudinal observational study used genomic and behavioral data from the Adolescent Brain Cognitive Development SM (ABCD(R)) Study, a multisite, population-based cohort of children recruited between 2016 and 2018 at ages 9 to 10 years from 21 research centers across the United States. A three-wave temporal design was employed, utilizing data from baseline (T0), Year 1 (T1), and Year 2 (T2) follow-ups. Primary analyses focused on 5,618 participants of genetically inferred European (EUR) ancestry, with exploratory analyses conducted in a diverse sample of 9,132 participants. ExposuresPolygenic scores (PGS) for AN and BE were calculated using summary statistics from the most recent genome-wide association studies. Mediators included BMI, ADHD, anxiety/depression, and social problems from the Child Behavioral Checklist assessed at Year 1 follow-up (T1). Main Outcomes and MeasuresParent reported DEB symptoms via the Kiddie Schedule for Affective Disorders and Schizophrenia (KSADS). For longitudinal association analyses, DEB were pooled across T0, T1 and T2 to assess the relationship between genetic liability and childhood symptom severity. For mediation analyses, DEB at T2 follow-up were used to ensure a clear temporal sequence between mediators at T1 and the outcomes. ResultsAmong 5,618 EUR participants (mean [SD] age, 9.91 [0.62] years; 47% female), longitudinal association models revealed that higher AN-PGS was associated with increased AN symptoms, while BE-PGS was associated with increased BE and AN symptoms. These patterns were largely consistent in exploratory cross-ancestry analyses. Mediation analyses showed that BMI mediated genetic risks across sexes, while ADHD and anxiety/depression symptoms emerged as additional mediators in females. Conclusions and RelevanceGenetic liabilities to AN and BE contribute to childhood DEB through sex-dependent pathways, highlighting the developmental continuity of ED risk from childhood. Integrating genetic profiles with behavioral markers may facilitate early identification and support multifaceted interventions. Key points QuestionDo genetic risks for anorexia nervosa (AN) and binge eating (BE) contribute to childhood disordered eating behaviors, and what mechanisms mediate these effects? FindingsIn this longitudinal study of 5,618 children of European ancestry, AN polygenic scores (AN-PGS) were associated with early AN symptoms, while BE-PGS showed transdiagnostic associations with both AN and BE symptoms. These links were mediated by BMI and psychosocial traits, including sex-specific pathways through ADHD and anxiety/depression symptoms in females. MeaningOur findings suggest that genetic liability to eating disorders manifests early in life through distinct metabolic and psychosocial pathways, highlighting a window for sex-specific targeted prevention.

Background: Attention problems are common transdiagnostic symptoms of psychiatric illness. Although environmental exposures and experiences influence attention during adolescent development, the underlying neural pathways by which they do so is unclear. Methods: We measured attention problems, attention-related brain networks, and multidimensional environmental experiences (the exposome) using data from the ABCD Study (N = 11,878). We tested whether the exposome is associated with 9-10-year-olds attention-related brain network strength and current and future attention problems. We further examined cross-sectional indirect pathways linking the exposome, brain network strength, and attention problems. Results: The exposome predicted youths current and future self-, caregiver-, and teacher-reported attention problems as well as their current attention-related brain network strength. This brain network signature of sustained attention also predicted attention problems from all three reporters. Indirect effects models revealed that the exposome was associated with current reported attention problems both directly and indirectly though this brain signature. Conversely, predictive brain network strength was related to attention problems both directly and indirectly through the exposome. Conclusion: Interactions between environmental exposures, experiences, and brain network organization are associated with attention problems in early adolescence. These findings support a bidirectional framework linking the environment and functional brain networks in the development of attention problems.

BackgroundAttention-deficit/hyperactivity disorder (ADHD) is the most common neurodevelopmental disorder and is a risk factor for later brain disorders. Here, we characterize the relationship between ADHD status and white matter cellularity across development and examine associations with medication, using a novel biophysical diffusion MRI model in youth aged 9 to 14 years. Methods: The ABCD Study(R) is a longitudinal cohort study with three biennial waves of brain MRI collection. Twenty-seven white matter tracts were delineated using multi-shell diffusion-weighted imaging (DWI) and tractography. Intracellular isotropic (RNI) and directional (RND) diffusion were quantified using the Restriction Spectrum Imaging (RSI) model. Longitudinal linear mixed-effect models characterize the effects of ADHD status and medication use on white matter cellularity across three waves. Results: By wave: 9,426 participants at baseline (mean [SD] age: 9.92 [0.63] years; 48.7% Female; 12.2% with ADHD), 6745 participants at 2-year (11.95 [0.65] years; 46.8% Female; 11.3% with ADHD), and 2,483 participants at 4-year (14.07 [0.69] years; 46.0% Female; 11.8% with ADHD). ADHD was associated with decreased RNI in 20 tracts at age 9, with evidence of developmental trajectory differences suggesting attenuation over early adolescence. We found enduring ADHD-associated decreases in RND of 16 tracts spanning ages 9 to 14 years, with methylphenidate effects on 2 tracts. Low-motion sensitivity analyses confirmed robust RNI findings, but not RND findings. ConclusionsADHD was associated with reductions in isotropic diffusion in white matter tracts, and possibly with complementary reductions in directional diffusion of select tracts. Isotropic diffusion findings suggest atypical glial cellularity in white matter during late childhood.

Background Although an expansive body of evidence exists on children's mental health during the COVID-19 pandemic, it is largely restricted to the early phases and lockdowns. This study examines longitudinal changes in child and youth mental health symptoms across two years of the COVID-19 pandemic, with data collection strategically timed to capture variability in pandemic restrictions. Methods A population-based longitudinal study of 1,261 children and youth aged 4-17 years followed prospectively from January 2021 to December 2022, with five waves of data collected in Ontario, Canada. Latent growth curve modelling was used to estimate trajectories of parent-reported mental health symptoms and identify baseline and time-varying covariates associated with variable trajectories. Findings Mental health symptoms were elevated and stable during lockdowns, followed by significant reductions as pandemic restrictions loosened, particularly for oppositional defiant and inattention/hyperactivity symptoms compared to internalizing symptoms. Children without pre-existing clinician diagnosed physical, mental or neurodevelopmental conditions and those not in lockdown at baseline demonstrated relative increases in mental health symptoms during lockdowns; and girls, compared to boys, demonstrated smaller reductions in internalizing symptoms as restrictions loosened. Concurrent and lagged associations between parental distress and children's mental health symptoms varied across the pandemic. Interpretation Variation in symptom trajectories by mental health domain, gender, pandemic restrictions and pre-existing diagnosed conditions underscores the need for tailored, equity-informed pandemic planning and response. Policies designed to optimize the balance between the need to reduce viral community transmission whilst limiting pandemic lockdowns may mitigate adverse impacts on child and youth mental health. Funding Ontario Ministry of Health

BackgroundAttention-deficit/hyperactivity disorder (ADHD) is a common heritable neurodevelopmental disorder, affecting [~]7 million children (11.4%) in the U.S. However, ADHDs underlying genetic architecture remains largely unknown. Transcriptome-wide association studies (TWAS), which integrate expression quantitative trait loci (eQTL) and GWAS summary data, can identify differentially expressed risk genes underlying complex phenotypes. Here we conduct a TWAS of ADHD using expression data from multiple brain tissues to improve understanding of the complex genetic architecture underlying this psychopathology. MethodsWe applied the TWAS framework OTTERS to train multiple gene expression imputation models using cis-eQTL summary statistics from MetaBrain for three brain regions: cortex (n=2,683), basal ganglia (n=208), and cerebellum (n=492), and GWAS summary statistics from the most recent meta-analysis of ADHD (n=225,534; case fraction =0.17). We further conducted fine-mapping, colocalization analysis, and functional enrichment analysis. ResultsWe identified 29 significant TWAS risk genes for ADHD (11 in cortex, 4 in basal ganglia, and 14 in cerebellum). Six genes appear novel for ADHD (MPL, C1orf210, MDFIC, NKX2-2, FAM183A, HIGD1A) while four genes were previously implicated in autism spectrum disorder (XRN2, KIZ, NKX2-4, NKX2-2). Pathway analysis indicated cortex and basal ganglia were enriched for neurodevelopmental pathways and regulation of cell development, and the protein-protein interaction network was statistically significant (p=1.12E-04). ConclusionThis multi-tissue TWAS refines the genetic architecture of ADHD by identifying genes whose genetically regulated expression is associated with risk, including six candidates not previously linked to ADHD. Together, these findings provide novel insights for potential targets in translational research and drug discovery.

BackgroundImpairments in cognitive functioning (CF) contribute to the onset, severity, and persistence of psychiatric symptoms. While specific CF domains may relate differentially to psychopathology, evidence also supports a general factor of cognitive impairment (the C-factor). We aimed to examine how general and domain-specific CF impairments relate to psychopathology using both diagnosis-specific and transdiagnostic symptom frameworks. MethodsData were drawn from five cognitive tasks administered in the deep-phenotyped, naturalistic MIND-Set cohort. A bifactor model of CF was estimated in a discovery sample (n = 206) and internally validated in a separate subsample (n = 312). Factor scores were then explored in relation to broad diagnostic clusters (stress-related disorders, neurodevelopmental disorders, comorbid disorders, and healthy controls), presence of specific diagnoses, number of diagnoses, and transdiagnostic symptom domains. ResultsThe bifactor model comprised a general CF factor (C-factor) and five specific subfactors--Reaction Time, Incompatibility, Working Memory, Inhibition, and Flexibility--and successfully replicated, although the general factor was relatively weak. Diagnosis-specific analyses showed that only individuals with stress-related disorders differed significantly from healthy controls on the C-factor and the Incompatibility factor. Higher impairment on the Incompatibility factor was associated with mood disorder diagnoses, while both the C-factor and Incompatibility factor were correlated with greater diagnostic burden. At the symptom level, the Incompatibility factor was associated with Negative Valence and Arousal domains, the C-factor with Negative Valence, and the Flexibility factor with Arousal. ConclusionThese findings indicate that broader cognitive impairment and deficits on tasks requiring inhibition under cognitive load are primarily related to mood disorders, ADHD, and transdiagnostic symptoms of negative valence and arousal. More generally, cognitive impairment appears to reflect symptom burden and transdiagnostic expression rather than diagnostic category alone, suggesting that dimensional symptom measures may provide a more informative framework for understanding cognitive impairment in clinical populations.

ObjectiveThere is little longitudinal research investigating links between violence exposure and mental disorders among children in low- and middle-income countries (LMICs), despite high rates of violence. We examined cross-sectional and longitudinal violence-mental health associations among children in a large South African birth cohort, the Drakenstein Child Health Study, including direct clinical interviews capturing childrens mental disorders. MethodIn this birth cohort (N=974), we assessed lifetime violence exposure and four subtypes (witnessed community, community victimization, witnessed domestic, domestic victimization) at ages 4.5 and 8-years via caregiver reports. At 8-years, caregivers completed the Child Behaviour Checklist; and psychiatric disorders were assessed using the Mini-International Neuropsychiatric Interview for Children and Adolescents, a self-report measure. We tested for associations using linear/logistic regressions, adjusted for confounders. ResultsMost children (91%) had experienced violence by 8-years. Cross-sectionally, total violence exposure was associated with total (B =0.49 [95% CI 0.32, 0.66]), internalizing (0.32 [0.17, 0.47]), and externalizing problems (0.46 [0.31, 0.61]), and with increased odds of disorder at 8 years (aOR=1.09 [1.05, 1.13]). Longitudinally, total violence exposure up to 4.5-years was associated with total (B=0.27 [0.03, 0.52]), internalizing (0.24 [0.04. 0.44]), and externalizing scores (0.23 [0.008, 0.45]) at 8-years, but not with increased risk of psychiatric disorders. The strongest and most consistent associations were observed for domestic versus community violence subtypes. ConclusionOur strong cross-sectional but weaker longitudinal findings suggest that recent violence exposures may be more critical than early exposures for childrens mental health. Longitudinal exploration of other violence-affected LMIC populations is urgently needed.