From infancy to eight: How early maternal mental health, emotion reminiscing, and language shape children's mental health.

To test the transmission of mental health difficulties from mother to child, we examined mediation through emotion reminiscing conversations and child language. Maternal depression symptoms were measured at 9 months post-partum, and child mental health outcomes were measured at age 8 years. Emotion reminiscing conversations between 1,234 mother-child pairs (624 boys, 610 girls) were recorded as part of a large, diverse, longitudinal cohort Growing Up in New Zealand. The 1,234 reminiscing conversations were transcribed and coded for maternal elaboration and emotion resolution quality (mother and child). The coded reminiscing variables did not mediate the pathway from maternal depression to child mental health outcomes; however, each maternal reminiscing variable together with child language skill serially mediated the relationship from maternal depression symptoms to child-reported anxiety and depression symptoms, and parent-reported child externalizing symptoms. Language as a skill and it's use as a tool for making shared meaning from past events are highlighted as possible mechanisms for the intergenerational transmission of mental health difficulties. These findings point to potential opportunities for early interventions, including prevention of and support for postnatal depression, family intervention in reminiscing training, and supporting child language development.

Association between maternal depression symptoms and child telomere length.

The biological mechanisms that explain how adverse early life events influence adult disease risk are poorly understood. One proposed mechanism is via the induction of accelerated biological aging, for which telomere length is considered a biomarker. We aimed to determine if maternal depression pre- and post-partum was associated with telomere length in children at 4 years of age (n = 4299). Mothers completed structured questionnaires assessing depression during pregnancy (Edinburgh Depression Scale), at 9 months (Edinburgh Depression Scale), and at 54 months postpartum (Patient Health Questionnaire 9). Regression methods were used to investigate the relationship between telomere length (DNA from saliva) and maternal depression score recorded at each stage. Significant covariates included in the final model were: maternal age at pregnancy; child sex; child ethnicity; gestational age group, and rurality group. Child telomere length was found to be longer if their mother had a higher depression score at both postpartum time points tested (9 months of age; coefficient 0.003, SE = 0.001, P = 0.01, 54 months of age; coefficient 0.003, SE = 0.002, P = 0.02). Although these findings seem paradoxical, increased telomere length may be an adaptive response to early life stressors. We propose several testable hypotheses for these results and to determine if the positive association between depression and telomere length is a developmental adaptation or an indirect consequence of environmental factors.

EEG Complexity Analysis of Brain States, Tasks and ASD Risk.

Autism spectrum disorder is an increasingly prevalent and debilitating neurodevelopmental condition and an electroencephalogram (EEG) diagnostic challenge. Despite large amounts of electrophysiological research over many decades, an EEG biomarker for autism spectrum disorder (ASD) has not been found. We hypothesized that reductions in complex dynamical system behaviour in the human central nervous system as part of the macroscale neuronal function during cognitive processes might be detectable in whole EEG for higher-risk ASD adults. In three studies, we compared the medians of correlation dimension, largest Lyapunov exponent, Higuchi's fractal dimension, multiscale entropy, multifractal detrended fluctuation analysis and Kolmogorov complexity during resting, cognitive and social skill tasks in 20 EEG channels of 39 adults over a range of ASD risk. We found heterogeneous complexity distribution with clusters of hierarchical sequences pointing to potential cognitive processing differences, but no clear distinction based on ASD risk. We suggest that there is indication of statistically significant differences between complexity measures of brain states and tasks. Though replication of our studies is needed with a larger sample, we believe that our electrophysiological and analytic approach has potential as a biomarker for earlier ASD diagnosis.

Maternal depressive symptoms and child language development: Exploring potential pathways through observed and self-reported mother-child verbal interactions.

Maternal depressive symptoms (MDS) in the postnatal period may impact children's later development through poorer quality parent-child interactions. The current study tested a specific pathway from MDS (child age 9 months) to child receptive vocabulary (4 ½ years) through both self-reported and observed parent-child verbal interactions (at both 2 and 4 ½ years). Participants (n = 4,432) were part of a large, diverse, contemporary pre-birth national cohort study: Growing Up in New Zealand. Results indicated a direct association between greater MDS at 9 months and poorer receptive vocabulary at age 4 ½ years. There was support for an indirect pathway through self-reported parent-child verbal interactions at 2 years and through observed parent-child verbal interactions at 4 ½ years. A moderated mediation effect was also found: the indirect effect of MDS on child vocabulary through observed verbal interaction was supported for families living in areas of greater socioeconomic deprivation. Overall, findings support the potential role of parent-child verbal interactions as a mechanism for the influence of MDS on later child language development. This pathway may be particularly important for families experiencing socioeconomic adversity, suggesting that effective and appropriate supportive parenting interventions be preferentially targeted to reduce inequities in child language outcomes.

Proximal Processes and Contextual Factors Associated with Early Socio-emotional Competence Development.

There is growing interest in child socio-emotional competence from parents, educators, employers and policy makers, with emphasis on developing it as early as possible. The aim of the present study was to examine contextual and proximal factors that influence socio-emotional competence development across the first five years of a child's life. We used data from 3200 mothers and their children drawn mostly from four major data collection waves (antenatal, 9 months, 2 years and 4.5 years) of the population-based longitudinal study, Growing Up in New Zealand. Regression analyses were carried out to identify the predictors of socio-emotional competence after controlling for demographics and prior score(s) of socio-emotional competence. We found that specific maternal behaviours, such as playing games and playing with toys with children, singing songs or telling stories to them, reading books with them, having rules around viewing TV, DVDs and videos, and praising children have a positive effect on socio-emotional competence. Parental relationship warmth and less family stress at 9 months also made positive contributions to socio-emotional competence at 9 months and 2 years. In contrast, attending childcare and having more siblings at home negatively predicted socio-emotional competence at 9 months. Mother's unemployment, living in neighbourhoods perceived as negative and being in contact with family and social services were negatively associated with concurrent socio-emotional competence at 2 years. Overall, more and/or stronger contemporaneous effects were found suggesting that negative effects of contextual factors may not have lasting impact on socio-emotional competence. In addition, the results showed that maternal behaviours need to be practised regularly to have positive impact on child's socio-emotional development.

Behavioural outcomes of children exposed to antidepressants and unmedicated depression during pregnancy.

BACKGROUND: Antenatal exposure to both antidepressants and maternal depression has been associated with child behavioural difficulties. However, previous research has not adequately distinguished between the effects of the antidepressants and the underlying maternal depression. METHODS: Child behavioural difficulties were assessed using the Strengths and Difficulties Questionnaire at 2-, 4.5-, and 8-years of age by mothers in the Growing Up in New Zealand study (N = 6233 at 2-years; N = 6066 at 4.5-years; N = 4632 at 8-years). Mothers were classified as either on antidepressants, unmedicated depression, or neither based on self-reported antidepressant intake during pregnancy and the Edinburgh Postnatal Depression Scale. Hierarchical multiple logistic regressions were used to examine whether antenatal exposure to antidepressants and unmedicated depression had a differential association with child behavioural outcomes relative to no exposure. RESULTS: When later life depression in the mother and a range of birth and sociodemographic variables were accounted for, neither antenatal exposure to unmedicated depression or antidepressants remained associated with an increased risk of behavioural difficulties at the ages investigated. However, maternal later life depression was associated with behavioural difficulties in the fully adjusted analyses at all three ages investigated. LIMITATIONS: The current study relied on mother-report of child behaviour which may be susceptible to bias due to maternal mental health problems. CONCLUSIONS: Adjusted results did not show an adverse association between antenatal antidepressant exposure or unmedicated depression in relation to child behaviour. Findings also suggest that efforts to improve child behaviour need to include more family-based approaches that support maternal wellbeing.

Age at first exposure to antibiotics and neurodevelopmental outcomes in childhood.

RATIONALE: Viral illnesses in children are common and are frequently treated with antibiotic medication. Antibiotics reduce the diversity and composition of the gut microbiota, leading to poor developmental outcomes. OBJECTIVES: To investigate the relationship between age at first exposure to antibiotics and cognitive and behavioural development at 4.5 years while controlling for multiple confounders, including otitis media. METHODS: Study participants were 5589 children enrolled in the broadly generalisable Growing Up in New Zealand cohort study, with antibiotic exposure data, maternal antenatal information, and age 4.5-year behaviour and cognitive outcome data. Children were categorised as first exposed to antibiotics according to the following mutually exclusive ages: 0-2 months; 3-5 months; 6-8 months; 9-11 months; 12-54 months or not exposed by 54 months. Developmental outcome measures included the Strengths and Difficulties Questionnaire, Luria hand clap task, and the Peabody Picture Vocabulary Test-III. RESULTS: In univariate analysis, there was an evident dose-response relationship where earlier exposure to antibiotics in the first year of life was associated with behavioural difficulties, lower executive function scores, and lower receptive language ability. After adjusting for confounders, pairwise comparisons showed that first antibiotic exposure between birth and 3 months or between 6 and 9 months was associated with lower receptive vocabulary. Antibiotic exposure at any age prior to 12 months was associated with increases in behavioural difficulties scores at 4.5 years. CONCLUSIONS: Following adjustment for socioeconomic factors and otitis media, there is evidence that antibiotic exposure during potentially sensitive windows of development is associated with receptive language and behaviour later in childhood.

The Association Between Persistence and Change in Behavioral Difficulties During Early to Middle Childhood and Cognitive Abilities at Age 8.

We investigated the association between persistence and change in behavioral difficulties during early to middle childhood and several cognitive outcomes. We observed 3904 8-year-olds enrolled in the longitudinal study Growing Up in New Zealand (50% male/female; 23% Maori, 9% Pacific Peoples, 13% Asian, 2% Middle Eastern/Latin American/African, 9% Other, 43% European). The NIH Toolbox Cognition Battery was used to assess cognitive functioning at 8 years and the Strengths and Difficulties Questionnaire for behavioral difficulties at 4.5 and 8 years. Multivariate logistic regression analyses were conducted, controlling for well-known sociodemographic confounders. Children with persistent or later onset of behavioral difficulties were at higher risk for poorer vocabulary, reading, inhibitory control/attention, episodic memory, working memory and processing speed at age 8 compared to children with no or improved difficulties. Our study supports the importance of addressing both cognitive and behavioral aspects when planning educational programmes and interventions in early and middle childhood.

Task-Modulated Oscillation Differences in Auditory and Spoken Chinese-English Bilingual Processing: An Electroencephalography Study.

Neurophysiological research on the bilingual activity of interpretation or interpreting has been very fruitful in understanding the bilingual brain and has gained increasing popularity recently. Issues like word interpreting and the directionality of interpreting have been attended to by many researchers, mainly with localizing techniques. Brain structures such as the dorsolateral prefrontal cortex have been repeatedly identified during interpreting. However, little is known about the oscillation and synchronization features of interpreting, especially sentence-level overt interpreting. In this study we implemented a Chinese-English sentence-level overt interpreting experiment with electroencephalography on 43 Chinese-English bilinguals and compared the oscillation and synchronization features of interpreting with those of listening, speaking and shadowing. We found significant time-frequency power differences in the delta-theta (1-7 Hz) and gamma band (above 30 Hz) between motor and silent tasks. Further theta-gamma coupling analysis revealed different synchronization networks in between speaking, shadowing and interpreting, indicating an idea-formulation dependent mechanism. Moreover, interpreting incurred robust right frontotemporal gamma coactivation network compared with speaking and shadowing, which we think may reflect the language conversion process inherent in interpreting.

Fostering Resilience Among Mothers Early (FRAME): using growth mixture modeling to identify resources that mitigate perinatal depression.

The primary objective of this study was to delineate classes of individuals based on depression trajectories from the antenatal period through 54-month postpartum and internal and external resources that are associated with low depression risk. Participants came from the Growing Up in New Zealand (GUiNZ) study (n = 5664), which is a pregnancy cohort study and is nationally representative of the ethnic and socioeconomic diversity of contemporary New Zealand births. Growth curve mixture modeling was used to identify distinct subgroups based on depression scores from the antenatal period through 54-month postpartum. Logistic regression models were run to investigate socioeconomic factors and internal and external resources that were associated with depression class membership. A two-class model, "low risk" and "high risk," resulted in the best model fit. Most of the sample (n = 5110, 90%) fell into the "low-risk" class defined by no-to-mild depression symptoms during pregnancy and decreasing depressive symptoms over time (bintercept = - .05, bslope = - .05). Approximately 10% of the sample fell into the "high-risk" class (n = 554, 10%) defined by mild-to-moderate depressive symptoms during pregnancy and increasing depressive symptomology over time (bintercept = .39, bslope = .57). More positive parenting-related attitudes, better pre-pregnancy self-reported health, informal social supports, and community belonging were significantly associated with greater odds of being in the "low-risk" class, after controlling for socioeconomic factors. These findings suggest that targeting internal and external resources for individuals across the perinatal and early childhood periods is important to mitigating maternal depression.

Associations between antenatal maternal diet and other health aspects with infant temperament in a large multiethnic cohort study: a path analysis approach.

OBJECTIVES: The aim of this study was to assess the association of antenatal maternal dietary patterns (DPs) and other health aspects with infant temperament in a large multiethnic cohort, taking maternal personality and prenatal stress into account. DESIGN AND METHODS: Using data from 3968 children born in 2009/2010 and their mothers from the Growing Up in New Zealand cohort, infant temperament was assessed at 9 months using the Infant Behavior Questionnaire-Revised Very Short Form. Maternal antenatal diet and other health aspects were assessed antenatally. Maternal DPs (n=4) were derived using principal components analysis based on food intake reported on a 44-item food frequency questionnaire. Path analyses investigated factors associated with infant temperament, namely maternal personality, prenatal maternal stress, DPs and other health aspects, including potential inter-relations and mediating effects. RESULTS: Women who scored higher in the fusion DP (standardised beta (ß)=0.05; 95% CI 0.02 to 0.09) and healthy DP (ß=0.05; 95% CI 0.02 to 0.09), who exercised more (ß=0.04; 95% CI 0.01 to 0.07), and who drank less alcohol (ß=-0.05; 95% CI -0.08 to -0.02) were more likely to have infants with an overall less difficult temperament. Sex-specific differences were found in the associations between maternal DP and infant temperament. Maternal personality and prenatal stress were significantly associated with all dimensions of infant temperament. The strongest predictors for a more difficult temperament were prenatal stress (ß=0.12; 95% CI 0.08 to 0.15) and the personality dimensions neuroticism (ß=0.10; 95% CI 0.07 to 0.14) and extraversion (ß=-0.09; 95% CI -0.12 to -0.06). CONCLUSIONS: Associations of antenatal maternal diet and health aspects with infant temperament were statistically significant but small. While they should not be overinterpreted as being deterministic, the findings of this study support the link between maternal modifiable health-related behaviours and infant temperament outcomes.

Prenatal determinants of depressive symptoms in childhood: Evidence from Growing Up in New Zealand.

BACKGROUND: Young people who experience depression are at an increased risk of adverse psychosocial and developmental outcomes that can persist over the lifecourse. Identifying maternal prenatal risk factors that may contribute to childhood depressive symptoms can be useful when considering mental health intervention. METHODS: The current study included 3,925 children from the Growing Up in New Zealand (GUiNZ) study who had complete data for self-reported depressive symptoms and mothers' antenatal information. Depressive symptoms were measured at age 8 using the Centre for Epidemiological Studies Depression Scale for Children (CESD-10) short form questionnaire. Hierarchical linear regression was used to determine the relationship between prenatal factors and depressive symptoms at age 8. RESULTS: When controlling for sociodemographic characteristics, our hierarchical linear regression revealed that the most significant maternal prenatal predictors of high depressive symptoms at age 8 were maternal perceived stress, smoking during pregnancy, body mass index (BMI) in the overweight/obese range, and paracetamol intake. LIMITATIONS: One limitation with the current study was a reduction in the sample due to attrition. This may have affected our statistical power, reflected in our modest effect sizes. The sample remained both socioeconomically and ethnically diverse, however our results should be interpreted with respect to the sample and not the whole New Zealand population. CONCLUSIONS: A combination of maternal mental health and lifestyle factors contribute to depressive symptoms for children, possibly through foetal programming. Our results emphasise the importance of mental and physical health support for expectant mothers.

Do Patterns of Levels of Socio-emotional Competence During Early Childhood Predict Executive Function at 4.5 Years?

Socio-emotional competence and executive function both work together to meet the demands of the everyday environment. While many studies have focused on how various domains of socio-emotional competence are predicted by, or associated with executive function, the predictive influence of socio-emotional competence on executive function has largely been ignored despite strong theoretical links. In addition, contradictory information exists with regard to the divergent validity of two subtypes of executive function: cool and hot. Using data from 4839 children participating in three data collection waves (9 months, 2 years and 4.5 year) in the Growing Up in New Zealand longitudinal study, we examined how different patterns of socio-emotional competence development during the early preschool years (persistent lows, recent low, improved and no lows) related to cool and hot executive function measured at aged 4.5 using a hand clap task and a gift wrap task, respectively. Findings showed that children with persistent lows (with no improvement) in the levels of early socio-emotional competence had increased odds of having below average cool and hot executive function at 4.5 years. However, no difference was found in the influence of socio-emotional competence on cool and hot executive function. Possible explanations for these associations between socio-emotional competence and executive function are discussed.

Prevalence of antidepressant use and unmedicated depression in pregnant New Zealand women.

BACKGROUND: Throughout pregnancy, women are at an increased risk of depression, with prevalence estimates between 6.5% and 18%. Global prevalence of antenatal antidepressant use is considerably lower at 3%. OBJECTIVE: The present study determined the proportion of women taking antidepressants across pregnancy in New Zealand. We investigated whether variation exists across age bands, area-level deprivation and ethnicities, and identified how many women experienced unmedicated depression. METHOD: Antenatal data (n = 6822) consisted of primarily third-trimester interviews conducted with mothers participating in Growing Up in New Zealand, a longitudinal study investigating child development. Women were asked about their antidepressant intake during pregnancy and assessed on antenatal depression symptoms using the Edinburgh Postnatal Depression Scale. Antidepressant use data were also compared to population-level data from Statistics New Zealand's Integrated Data Infrastructure. RESULTS: Antidepressant prevalence across pregnancy was 3.2%, with a 2.7% prevalence in trimester one and 2.6% following the first trimester. There was no significant difference in usage within age bands and area-level deprivation quintiles. Ethnicity-specific data revealed that Pasifika and Asian ethnicities had the lowest antidepressant use, and New Zealand Europeans the highest. The rate of unmedicated depression, where women met the Edinburgh Postnatal Depression Scale criteria for significant depressive symptoms but did not receive antidepressants during pregnancy, was 11.8%, indicating that antenatal depression treatment may be inadequate. Greater rates of unmedicated depression were seen for younger women (⩽24 years), those living in high deprivation areas and mothers of Pasifika, Asian and Maori ethnicities. CONCLUSIONS: Antenatal antidepressant use in New Zealand follows global prevalence estimates and highlights possible undertreatment of antenatal depression in New Zealand. Future research including other treatment types (e.g. behavioural therapy) is needed to evaluate whether undertreatment occurs across all treatment options.

Maternal depression trajectories and child BMI in a multi-ethnic sample: a latent growth modeling analysis.

BACKGROUND: Perinatal (antenatal and postpartum) depression impacts approximately 12% of mothers. Perinatal depression can impact everyday functioning for mothers, and the relationship with, and development of, their children. The purpose of this study was to investigate depression trajectories from the antenatal period through 54-months postpartum and associations with child body mass index at 54-months postpartum. METHODS: This study applied latent growth modeling to the Growing Up in New Zealand study, which is a longitudinal pregnancy cohort study that provides nationally representative-level data, to investigate associations between depression at three time points (antenatal, 9-months postpartum, 54-months postpartum) and child body mass index at 54-months (n=4897). RESULTS: The average slope of depression for this sample is low and decreases over time. When child BMI was added to the model as an outcome variable, both antenatal depression (B=.25, p<.01), and the rate of change of depression across the perinatal and postpartum periods (B=.09, p<.01) were associated with child BMI at 54-months postpartum. After controlling for sociodemographic characteristics, antenatal depression, but not the slope of depression, remained significantly associated with child BMI (B=.05, p<.05). When controlling for maternal pre-pregnancy BMI the effect of antenatal depression on child BMI at 54-months was entirely attenuated (χ2 (9) = 39.60, p < .05, SRMR = 0.01, CFI = .99, RMSEA = 0.03, BIC=53213). CONCLUSIONS: Our findings align with the Developmental Origins of Health and Disease theory and imply that both the physical and mental health of mothers during pregnancy may be important indicators of child growth and development outcomes. Early intervention directed towards women who have even mild depression scores during pregnancy may promote healthy child development outcomes. Additionally, given the heterogeneity of depressive symptoms over time seen in this study, multiple assessment periods across the postpartum period may be valuable to adequately address and support maternal mental health.

Patterns of risk exposure in first 1,000 days of life and health, behavior, and education-related problems at age 4.5: evidence from Growing Up in New Zealand, a longitudinal cohort study.

BACKGROUND: Children who are high priority candidates for early intervention need to be identified to reduce their risk for experiencing problems in development. Those exposed to multiple risk factors are more likely to exhibit problems in development than those exposed to a single or no risk factor. We examined the longitudinal associations between persistence and timing of exposure to cumulative risk (CR) on three occasions by age 2 and problems in development at age 4.5 in health, behavior, and education-related domains. METHODS: Data are from Growing Up in New Zealand (NZ), a prospective longitudinal study of a birth cohort first assessed during their last trimester in 2009-10 and followed at ages 9 months and 2 and 4.5 years. All women with an expected delivery date in a 12-month period who resided within a defined region were invited to participate, with no additional eligibility criteria. Exposure was measured for 12 sociodemographic and maternal health risk factors at third trimester and ages 9 months and 2 years, from which developmental trajectories were constructed capturing persistence and timing of CR exposure. Ten developmental outcomes were measured at age 4.5 to classify problems in overall health status, obesity, and injuries; internalizing and externalizing behavior problems; and letter naming, counting forward and backward, and expectations for starting school and completing education. RESULTS: Analyses of data from 6156 children (49% female, 33% Non-European ethnicity) who participated in the 4.5-age assessment uniformly showed associations between exposure to more than consistently zero CR across early development and higher prevalence of being classified with problems for 9 of 10 outcomes. Persistent exposure to a CR ≥ 4 was generally associated with a higher prevalence of problems for 7 of 10 outcomes, whereas the timing of first exposure to CR ≥ 4 showed a less consistent association with problem outcomes. CONCLUSIONS: These findings are concerning because over 50% of NZ children are exposed to at least one of these risk factors at some point in early development. Routine screening of most of these risk factors during pregnancy is feasible and can identify priority candidates for intervention.

Factor structure of the SDQ and longitudinal associations from pre-school to pre-teen in New Zealand.

OBJECTIVE: The objective of this study was to assess the validity of the Strengths and Difficulties Questionnaire in a cohort of New Zealand children followed from birth to the age of eleven. The study also aimed to assess the stability of the child data in relation to behavioural outcomes during this period. METHODS: Children in the Auckland Birthweight Collaborative Study were assessed at approximately 3½, 7 and 11 years of age. At all time-points parents completed the parent version of the Strengths and Difficulties Questionnaire, and the children themselves completed the self-report version at 11 years of age. The validity and internal consistency were assessed using exploratory factor analysis, Cronbach's alpha, and McDonald's Omega. Cross tabulations and Chi-square statistics were used to determine whether Total Difficulty scores, as per accepted cut-offs, remained stable over time (between normal and abnormal/borderline categories). RESULTS: The factor structure remained relatively consistent across all three time-points, though several questions did not load as per the originally published factor analysis at the earliest age. The internal consistency of the Strengths and Difficulties Questionnaire was good at all time-points and for parent- and child-completed versions. There was low agreement in the total scores between time points. CONCLUSIONS: The factor analysis shows that the Strengths and Difficulties Questionnaire has a similar factor structure, particularly in older ages, to that previously published and shows good internal consistency. At the pre-school follow up, a larger than expected proportion of children were identified with high scores, particularly in the conduct sub-scale. Children's behaviour changes over time, with only poor to moderate agreement between those identified as abnormal or borderline over the longitudinal follow up.

Exploring the Factor Structure of the NIH Toolbox Cognition Battery in a Large Sample of 8-Year-Old Children in Aotearoa New Zealand.

OBJECTIVE: The objective of this study was to derive a factor structure of the measures of the National Institutes of Health (NIH) Toolbox Cognition Battery (CB) that is representative of cognitive abilities in a large ethnically diverse cohort of 8-year-old children in Aotearoa New Zealand. METHODS: Our sample comprised of 4298 8-year-old children from the Growing Up in New Zealand study. We conducted exploratory and confirmatory factor analysis for the NIH Toolbox CB measures to discover the best-fitting factor structure in our sample. Measurement invariance of the identified model was tested across child's gender, socio-economic status (SES), and ethnicity. RESULTS: A three-dimensional factor structure was identified, with one factor of Crystallised Cognition (Reading and Vocabulary), and two distinguished factors of fluid cognition: Fluid Cognition I (Attention/Inhibitory Control, Processing Speed, and Cognitive Flexibility) and Fluid Cognition II (Working Memory, Episodic Memory). The results demonstrate excellent model fit, but reliability of the factors was low. Measurement invariance was confirmed for child's gender. We found configural, but neither metric nor scalar, invariance across SES and the four major ethnic groups: European, Maori, Pacific Peoples, and Asian. CONCLUSION: Our findings show that, at the age of 8 years, fluid abilities are more strongly associated with one another than with crystallised abilities and that fluid abilities need to be further differentiated. This dimensional structure allows for comparisons across child's gender, but evaluations across SES and ethnicity within the Aotearoa New Zealand context must be conducted with caution. We recommend using raw scores of the individual NIH Toolbox CB measures in future research.

Physical Activity, Sleep, Body Mass Index, and Associated Risk of Behavioral and Emotional Problems in Childhood.

OBJECTIVE: Cross-sectional data indicate that physical activity, longer sleep duration, and normal body weight are associated with better mental health in childhood. It is less clear whether these factors protect against future emotional and behavioral problems. We investigated whether physical activity, sleep duration, and body mass index (BMI) at the age of 7 years are associated with emotional and behavioral problems at the age of 11 years. METHODS: Children born to European mothers enrolled in the prospective longitudinal Auckland Birthweight Collaborative Study (N = 871) were assessed at birth and ages 7 and 11 years. Physical activity and sleep duration were measured using accelerometer. BMI was calculated from height and weight measurement. Outcome variables assessed at the age of 11 years were parent and child self-report Strengths and Difficulties Questionnaire and parent and teacher Conners' Rating Scale scores. RESULTS: Physical activity, sleep duration, and BMI at the age of 7 years were not significantly associated with emotional and behavioral problems at the age of 11 years. In cross-sectional analysis at the age of 11 years, there was no significant association between physical activity or sleep duration and emotional and behavioral problems. Children with a BMI in the overweight or obese range were significantly more likely to have teacher-rated behavior problems and parent-rated emotional or behavioral problems after adjustment for potential confounders. CONCLUSION: Although physical activity and sleep have physical health benefits, they may not be protective against future emotional and behavioral problems in childhood in the general population. BMI in the obese or overweight range was significantly associated with current emotional and behavioral problems at the age of 11 years.

The Association Between Persistence and Change in Early Childhood Behavioural Problems and Preschool Cognitive Outcomes.

The link between behavioural and cognitive difficulties is well established. However, research is limited on whether persistence and change in behavioural difficulties relates to cognitive outcomes, particularly during preschool. We used a large New Zealand birth cohort to investigate how persistence and change in serious behavioural problems from ages 2 to 4.5 years related to measures of cognitive delay at 4.5 years (n = 5885). Using the Strengths and Difficulties total problems score at each time point, children were categorised as showing no difficulties, improved behaviour, concurrent difficulties, and persistent difficulties. Cognitive measures assessed included receptive language, early literacy ability, and executive control. Our results showed that children with concurrent and persistent behavioural difficulties were at a greater risk of showing delays within specific cognitive domains relative to children with no difficulties and were also more likely to show comorbid delays across multiple cognitive domains.