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.

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.

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% Māori, 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.

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.

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 (β)=0.05; 95% CI 0.02 to 0.09) and healthy DP (β=0.05; 95% CI 0.02 to 0.09), who exercised more (β=0.04; 95% CI 0.01 to 0.07), and who drank less alcohol (β=-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 (β=0.12; 95% CI 0.08 to 0.15) and the personality dimensions neuroticism (β=0.10; 95% CI 0.07 to 0.14) and extraversion (β=-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.

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.

Patterns of Exposure to Cumulative Risk Through Age 2 and Associations with Problem Behaviors at Age 4.5: Evidence from Growing Up in New Zealand

Exposure to cumulative risk (CR) has important implications for child development, yet little is known about how frequency, persistence, and timing of CR exposure during early childhood predict behavioral problems already before school start. We examine prospective longitudinal associations between patterns of CR exposure from third trimester through 2 years and subsequent behavior problems at 4.5 years. In 6156 diverse children in the Growing Up in New Zealand longitudinal study, the presence of 12 risk factors, spanning maternal health, social status, and home and neighborhood environment, defined CR and were assessed at last trimester and 9 months and 2 years of age. At child age 4.5 years, mothers completed the Strengths and Difficulties Questionnaire, where a score ≥ 16 indicated an abnormal level of problem behaviors (ALPB). Children exposed to a CR ≥ 1 at least once in early development, compared to those with consistent CR = 0, showed a significantly higher likelihood of ALPB at 4.5 years. Consistent high exposure to CR ≥ 4 across all three assessments had the highest prevalence (44%) of ALPB at age 4.5. Children with high CR exposure on two of three, compared to on all three, time points in early development did not evidence a significantly reduced prevalence (32%-41%) of ALPB. The common co-occurrence of risk factors and their significant developmental impact when accumulated early in life underscore the need for systematic multisector intervention and policy implementation during pregnancy and shortly after birth to improve outcomes for vulnerable children.

Early adolescent physical activity, sleep and symptoms of depression at 16 years of age

AIM

To examine early adolescent physical activity and risk of later depressive symptoms at age 16 years in a prospective cohort study.

METHODS

Participants were children and parents enrolled at birth of the child. Approximately half the children enrolled in the Auckland Birthweight Collaborative Study were small for gestational age at birth (SGA ≤10th percentile for sex and gestation) and half were appropriate for gestational age (AGA >10th percentile). Maternal demographic data were collected at birth, and children were followed through to age 16 years. Depression at 16 was assessed using the Center for Epidemiological Studies Depression Scale for Children. Accelerometer measures of physical activity and sleep were measured at 11 years of age.

RESULTS

Moderate to severe depression was present in 15.6% of the 467 16-year-olds. Objectively measured physical activity and sleep at 11 years were not significantly associated with depressive symptoms at 16 years of age.

CONCLUSION

Prospectively collected objective measures of physical activity levels and sleep were not predictive of depressive symptoms later in adolescence in a healthy community cohort. While interventions to promote increased physical activity and sleep in adolescents who are depressed may be effective, physical activity and sleep in the general population of adolescents does not protect against future depression.

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.

Antenatal depression symptoms in Pacific women: evidence from Growing Up in New Zealand

INTRODUCTION Pacific women in New Zealand (NZ) have higher rates of antenatal depression than women from other ethnic groups. AIM To identify factors that are significantly associated with depression symptoms in pregnant Pacific women living in NZ. METHODS Data were collected from 5657 pregnant women, 727 of whom identified their ethnicity as Pacific Island. Antenatal depression symptoms were measured using the Edinburgh Depression Scale with scores above 12 indicating elevated antenatal depression symptoms (ADS). RESULTS Pacific women had significantly higher rates of ADS than non-Pacific women, with 23% of pregnant Pacific women experiencing ADS. Factors associated with ADS for Pacific women included age <25 years, moderate to severe nausea during pregnancy, perceived stress, family stress and relationship conflict. Not seeing the importance of maintaining one's Pacific culture and traditions and negative feelings towards NZ culture were also significantly associated with ADS in Pacific women. One in three Pacific women aged <25 years experienced ADS. Pregnant Pacific women without a family general practitioner (GP) before their pregnancy were 4.5-fold more likely to experience ADS than non-Pacific women with a regular GP. DISCUSSION Further attention is required to providing appropriate primary health care for Pacific women of child-bearing age in NZ. Better screening processes and a greater understanding of effective antenatal support for Pacific women is recommended to respond to the multiple risk factors for antenatal depression among Pacific women.

Antenatal determinants of early childhood talking delay and behavioural difficulties

The determinants of talking delay alone or its comorbidity with behavioural difficulties was examined in 5768 two-year-old members of the Growing Up in New Zealand longitudinal study. Using the MacArthur-Bates Communicative Development inventories and the total difficulties score from the preschool Strengths and Difficulties Questionnaire, a composite measure was created so that children were categorised as showing no language or behavioural concerns (72.5%), behavioural only difficulties (6.1%), language only difficulties (18.1%), and comorbid language and behavioural difficulties (3.3%). Analyses revealed that antenatal factors such as maternal perceived stress, inadequate folate intake, vitamin intake, alcohol consumption during the first trimester and maternal smoking all had a significant effect on child outcomes. In particular, low multivitamin intake and perceived stress during pregnancy were associated with coexisting language and behavioural difficulties. These findings support international research in showing that maternal factors during pregnancy are associated with developmental outcomes in the early childhood period, and demonstrate these associations within a NZ context. Interventions which address maternal stress management and health behaviours during pregnancy could be beneficial to offspring development.

Persistence and change in behavioural problems during early childhood

BACKGROUND

Behavioural problems and psychopathology can present from as early as the preschool period. However there is evidence that behavioural difficulties may not be stable over this period. Therefore, the current study was interested in evaluating the persistence and change in clinically relevant behavioural problems during early childhood in a population-based New Zealand birth cohort.

METHODS

Behaviour was assessed in 5896 children when they were aged 2 and 4.5 years using the Strengths and Difficulties Questionnaire (SDQ). Correlations and mean differences in subscale and total difficulties scores were examined. Scores were then dichotomised into normal/borderline and abnormal ranges to evaluate the persistence and change in significant behavioural problems. Chi-square analyses and ANOVAs were used to determine the association between sociodemographic and birth variables, and preschool behavioural stability.

RESULTS

Raw scores at ages 2 and 4.5 years were moderately correlated, with most measures showing a small but significant decrease in mean scores over time. The majority of children who showed abnormal behaviour at 2 years improved at 4.5 years (57.9% for total difficulties). However, a notable proportion persisted in their difficulties from 2 to 4.5 years (42.1% for total difficulties). There was a small percentage of children who were categorised as abnormal only at 4.5 years. Children with difficulties at one or both time points had a greater proportion who were the result of an unplanned pregnancy, lived in highly deprived urban areas, and had mothers who were younger, of Māori and Pacific ethnicity and were less educated.

CONCLUSIONS

Not all children who show early behavioural difficulties persist in these difficulties. Those whose difficulties persist were more likely to experience risk factors for vulnerability relative to children with no difficulties. Results suggest that repeated screening for early childhood behavioural difficulties is important.

A longitudinal study of antenatal and perinatal risk factors in early childhood cognition: Evidence from Growing Up in New Zealand

BACKGROUND

Poor maternal health, disadvantageous exposures during pregnancy and unfavourable perinatal events are associated with adverse trajectories in offspring cognitive development.

AIM

To examine longitudinal associations between antenatal maternal, perinatal and maternal health characteristics and children's early cognitive development across executive control, motor ability and receptive language domains.

STUDY DESIGN, SUBJECTS AND OUTCOME MEASURES

Analyses comprised interview and observational data from 4587 children and their mothers enrolled in the longitudinal Growing Up in New Zealand cohort study. Children's executive control (Luria hand clap task), motor skills (mothers' report) and receptive language ability (Peabody Picture Vocabulary Test) were assessed at age 4.5 years. Multivariate logistic regression analyses were conducted, controlling for sociodemographic factors.

RESULTS

Smoking pre- and during pregnancy, no folate intake during first trimester and low birth weight were risk factors for poorer executive control. Perceived stress during pregnancy, no folate intake during first trimester and low birth weight were all risk factors for poorer motor ability. Smoking pre-pregnancy, antenatal anxiety and no folate intake during first trimester were risk factors for poorer receptive language ability.

CONCLUSION

Adverse ante- and perinatal environments are associated with poorer executive control, motor and receptive language abilities in early childhood. Improving maternal education and support especially for more disadvantaged mothers during pregnancy may reduce the potential deleterious impact of adverse ante- and perinatal conditions on children's early cognition.

No evidence for systematic white matter correlates of dyslexia: An Activation Likelihood Estimation meta-analysis

Dyslexia is a prevalent neurodevelopmental disorder, characterized by reading and spelling difficulties. Beyond the behavioral and functional correlates of this condition, a growing number of studies have explored structural differences between individuals with dyslexia and typically developing individuals. To date, findings remain disparate - some studies suggest differences in fractional anisotropy (FA), an indirect measure of white matter integrity, whereas others do not identify significant disparities. Here, we synthesized the existing literature on this topic by conducting a meta-analysis of Diffusion Tensor Imaging (DTI) studies investigating white matter correlates of dyslexia via voxel-based analyses (VBA) of FA. Our results showed no reliable clusters underlying differences between dyslexics and typical individuals, after correcting for multiple comparisons (false discovery rate correction). Because group comparisons might be too coarse to yield subtle differences, we further explored differences in FA as a function of reading ability, measured on a continuous scale. Consistent with our initial findings, reading ability was not associated with reliable differences in white matter integrity. These findings nuance the current view of profound, structural differences underlying reading ability and its associated disorders, and suggest that their neural correlates might be more subtle than previously thought.

Human Sensory LTP Predicts Memory Performance and Is Modulated by the BDNF Val66Met Polymorphism

Background: Long-term potentiation (LTP) is recognised as a core neuronal process underlying long-term memory. However, a direct relationship between LTP and human memory performance is yet to be demonstrated. The first aim of the current study was thus to assess the relationship between LTP and human long-term memory performance. With this also comes an opportunity to explore factors thought to mediate the relationship between LTP and long-term memory. The second aim of the current study was to explore the relationship between LTP and memory in groups differing with respect to brain-derived neurotrophic factor (BDNF) Val⁶⁶Met; a single-nucleotide polymorphism (SNP) implicated in memory function.

Methods: Participants were split into three genotype groups (Val/Val, Val/Met, Met/Met) and were presented with both an EEG paradigm for inducing LTP-like enhancements of the visually-evoked response, and a test of visual memory.

Results: The magnitude of LTP 40 min after induction was predictive of long-term memory performance. Additionally, the BDNF Met allele was associated with both reduced LTP and reduced memory performance.

Conclusions: The current study not only presents the first evidence for a relationship between sensory LTP and human memory performance, but also demonstrates how targeting this relationship can provide insight into factors implicated in variation in human memory performance. It is anticipated that this will be of utility to future clinical studies of disrupted memory function.

Volumetric and surface characteristics of gray matter in adult dyslexia and dyscalculia

Dyslexia, dyscalculia and their comorbid manifestation are prevalent disorders associated with well-documented behavioral manifestations. However, attempts to relate these manifestations to abnormalities in brain structure have yielded mixed results, with no clear consistency across a range of measures. In this study, we used a unique design including adults with dyslexia, dyscalculia, both disorders and controls, to explore differences in gray matter characteristics across groups. Specifically, we examined whether dyslexia, dyscalculia, or their comorbid manifestation could be related to volumetric and surface characteristics of gray matter, using voxel-based and surface-based morphometry. We demonstrate with Bayesian analyses that the present data favor the null model of no differences between groups across the brain, a result that is in line with recent findings in this field of research. Importantly, we provide detailed statistical maps to enable robust assessment of our findings, and to promote cumulative evaluation of the evidence. Together, these findings suggest that gray matter differences associated with dyslexia and dyscalculia might not be as reliable as suggested by previous literature, with important implications for our understanding of these disorders.

Antenatal and Postnatal Determinants of Behavioural Difficulties in Early Childhood: Evidence from Growing Up in New Zealand

Behavioural difficulties during early childhood have significant implications for multiple outcomes later in life. Child behavioural difficulties at 2 years of age (N = 6246) were assessed by mothers enrolled in a longitudinal, population-based New Zealand cohort study. 10.1% of children had total difficulties scores in the abnormal range on the preschool version of the Strengths and Difficulties Questionnaire. After controlling for maternal education, poverty, and child's birth age/weight, several antenatal and postnatal maternal health and family risk factors were significant for: (i) emotional problems (antenatal maternal perceived stress, lack of periconceptional folate, and moderate to severe maternal postnatal anxiety); (ii) hyperactivity-inattention (antenatal maternal perceived stress, mothers' antenatal exposure to secondhand smoke, moderate to severe maternal postnatal anxiety, and low maternal self-evaluation); (iii) conduct problems and total difficulties (antenatal maternal perceived stress, verbal inter-parental conflict and low maternal self-evaluation). The identification of risk and protective factors associated with early childhood difficulties are vital for guiding intervention and prevention efforts.

Prenatal alcohol consumption and infant and child behavior: Evidence from the Growing Up in New Zealand Cohort

BACKGROUND

High levels of alcohol exposure during pregnancy can damage developing brains and influence child behavior and learning.

AIM

To examine the effects of lower levels of alcohol and very early exposure to alcohol on infant temperament and child behavior.

STUDY DESIGN, SUBJECTS, AND OUTCOME MEASURES

The Growing Up in New Zealand study involves a prospective birth cohort of 6822 pregnant women of whom 6156 provided information on their child's temperament using the Infant Behavior Questionnaire-Revised (IBQ-R VSF) at 9 months and their child's behavior using the Strengths and Difficulties Questionnaire at 2 years.

RESULTS

A series of adjusted linear regression models controlling for socio-demographic factors found alcohol consumption during pregnancy was most consistently related to Lower Positive Affect, Affiliation/Regulation, and Orienting Capacity temperament scores. Mothers who stopped drinking after becoming aware of their pregnancy, but had an unplanned pregnancy (hence may have a baby exposed to alcohol for longer), also reported infants with lower Orienting Capacity, Affiliation/Regulation, and Fear temperament scores compared to those that did not drink. Children whose mothers drank four or more drinks per week during pregnancy were more likely to report their child as having conduct problems, with higher total difficulties scores at age 2.

CONCLUSIONS

Alcohol consumption during pregnancy has a negative effect especially on infant temperament, even if small amounts of alcohol are consumed. Our findings have implications for men and women who drink, medical professionals, and for the availability of contraception to those who drink, but do not plan to get pregnant.

No evidence for systematic white matter correlates of dyslexia and dyscalculia

Learning disabilities such as dyslexia, dyscalculia and their comorbid manifestation are prevalent, affecting as much as 15% of the population. Structural neuroimaging studies have indicated that these disorders can be related to differences in white matter integrity, although findings remain disparate. In this study, we used a unique design composed of individuals with dyslexia, dyscalculia, both disorders and controls, to systematically explore differences in fractional anisotropy across groups using diffusion tensor imaging. Specifically, we focused on the corona radiata and the arcuate fasciculus, two tracts associated with reading and mathematics in a number of previous studies. Using Bayesian hypothesis testing, we show that the present data favor the null model of no differences between groups for these particular tracts—a finding that seems to go against the current view but might be representative of the disparities within this field of research. Together, these findings suggest that structural differences associated with dyslexia and dyscalculia might not be as reliable as previously thought, with potential ramifications in terms of remediation.

•

Previous literature indicates important discrepancies in structural differences associated with dyslexia and dyscalculia

•

We explore the relationship between these disorders and fractional anisotropy, a measure of white matter integrity

•

We show support for the null model in the corona radiata and the arcuate fasciculus

•

This suggests that structural differences associated with these disorders are not as reliable as previously thought

The Strengths and Difficulties Questionnaire: Factor Structure of the Father-Report and Parent Agreement in 2-Year-Old Children

There is limited research on the preschool version of the Strengths and Difficulties Questionnaire (SDQ), and comparisons between mothers and fathers as informants and whether the factor structure shows measurement invariance across parents is lacking. Our study involved mothers (n = 6,246) and fathers (n = 3,759) of 2-year-old children from the Growing Up in New Zealand birth cohort. Confirmatory factor analysis was used to evaluate the factor structure of the SDQ and test for measurement invariance across mothers and fathers. For fathers, we found support for a modified five-factor model that accounts for a positive construal method effect. Internal consistency was good for measures except peer problems. Full measurement invariance of this modified model was found across mothers and fathers, and parents showed moderate agreement in their SDQ ratings (0.34 ≤ r ≤ 0.44). More research is needed on whether mother- and father-reports differ in sensitivity when screening for early childhood psychiatric disorders.

Reading network in dyslexia: Similar, yet different

Dyslexia is a developmental disorder characterized by reading and phonological difficulties, yet important questions remain regarding its underlying neural correlates. In this study, we used partial least squares (PLS), a multivariate analytic technique, to investigate the neural networks used by dyslexics while performing a word-rhyming task. Although the overall reading network was largely similar in dyslexics and typical readers, it did not correlate with behavior in the same way in the two groups. In particular, there was a positive association between reading performance and both right superior temporal gyrus and bilateral insula activation in dyslexic readers but a negative correlation in typical readers. Together with differences in lateralization unique to dyslexics, this suggests that the combination of poor reading performance with high insula activity and atypical laterality is a consistent marker of dyslexia. These findings emphasize the importance of understanding right-hemisphere activation in dyslexia and provide promising directions for the remediation of reading disorders.

High-intensity training enhances executive function in children in a randomized, placebo-controlled trial

Background:

Exercise-induced cognitive improvements have traditionally been observed following aerobic exercise interventions; that is, sustained sessions of moderate intensity. Here, we tested the effect of a 6 week high-intensity training (HIT) regimen on measures of cognitive control and working memory in a multicenter, randomized (1:1 allocation), placebo-controlled trial.

Methods:

318 children aged 7-13 years were randomly assigned to a HIT or an active control group matched for enjoyment and motivation. In the primary analysis, we compared improvements on six cognitive tasks representing two cognitive constructs (N = 305). Secondary outcomes included genetic data and physiological measurements.

Results:

The 6-week HIT regimen resulted in improvements on measures of cognitive control [BFM = 3.38, g = 0.31 (0.09, 0.54)] and working memory [BFM = 5233.68, g = 0.54 (0.31, 0.77)], moderated by BDNF genotype, with met66 carriers showing larger gains post-exercise than val66 homozygotes.

Conclusions:

This study suggests a promising alternative to enhance cognition, via short and potent exercise regimens.

Funding:

Funded by Centre for Brain Research.

Clinical trial number:

NCT03255499.

Exercise has beneficial effects on the body and brain. People who perform well on tests of cardiovascular fitness also do well on tests of learning, memory and other cognitive skills. So far, studies have suggested that moderate intensity aerobic exercise that lasts for 30 to 40 minutes produces the greatest improvements in these brain abilities.

Recently, short high-intensity workouts that combine cardiovascular exercise and strength training have become popular. Studies have shown that these brief bouts of strenuous exercise improve physical health, but do these benefits extend to the brain? It would also be helpful to know if the effect that exercise has on the brain depends on an individual’s genetic makeup or physical health. This might help to match people to the type of exercise that will work best for them.

Now, Moreau et al. show that just 10 minutes of high-intensity exercise a day over six weeks can boost the cognitive abilities of children. In the experiments, over 300 children between 7 and 13 years of age were randomly assigned to one of two groups: one that performed the high-intensity exercises, or a ‘control’ group that took part in less active activities – such as quizzes and playing computer games – over the same time period. The children who took part in the high-intensity training showed greater improvements in cognitive skills than the children in the control group. Specifically, the high-intensity exercise boosted working memory and left the children better able to focus on specific tasks, two skills that are important for academic success.

Moreau et al. further found that the high-intensity exercises had the most benefit for the children who needed it most – those with poor cardiovascular health and those with gene variants that are linked to poorer cognitive skills. This suggests that genetic differences do alter the effects of exercise on the brain, but also shows that targeted exercise programs can offer everyone a chance to thrive.

Moreau et al. suggest that exercise need not be time consuming to boost brain health; the key is to pack more intense exercise in shorter time periods. Further work could build on these findings to produce effective exercise routines that could ultimately form part of school curriculums, as well as proving useful to anyone who wishes to improve their cognitive skills.

Paternal Depression Symptoms During Pregnancy and After Childbirth Among Participants in the Growing Up in New Zealand Study

IMPORTANCE

Antenatal and postnatal depression are known to be common and associated with poor outcomes for women and their children. There is little evidence on depression symptoms among men during the perinatal period.

OBJECTIVE

To identify characteristics associated with depression symptoms among men whose partners were pregnant and subsequently gave birth.

DESIGN, SETTING, AND PARTICIPANTS

A longitudinal cohort study provided data from a demographically diverse sample of 3523 New Zealand men who completed interviews during their partner's pregnancy and 9 months after the birth of their child. Participants were drawn from a cohort whose partners were pregnant women with a due date between April 25, 2009, and March 25, 2010, who were enrolled in the Growing Up in New Zealand study. Data analysis was conducted from September 1, 2015, to January 8, 2016.

MAIN OUTCOMES AND MEASURES

Depression symptoms were measured using the Edinburgh Postnatal Depression Scale and the 9-item Patient Health Questionnaire; elevated depression symptoms were defined as scores higher than 12 and 9, respectively.

RESULTS

The mean (SD) age of the participants at the antenatal interview was 33.20 (6.25) years (range, 16-63 years). Elevated antenatal paternal depression symptoms affected 82 fathers (2.3%) and were associated with perceived stress (odds ratio [OR], 1.38; 95% CI, 1.30-1.47) and fair to poor health during their partner's pregnancy (OR, 2.06; 95% CI, 1.18-3.61). Elevated postnatal paternal depression symptoms affected 153 (4.3%) of fathers and were associated with perceived stress in pregnancy (OR, 1.12; 95% CI, 1.08-1.17), no longer being in a relationship with the mother 9 months after childbirth (OR, 6.36; 95% CI, 2.28-17.78), having fair to poor health at 9 months (OR, 3.29; 95% CI, 2.10-5.16), being unemployed at 9 months (OR, 1.86; 95% CI, 1.11-3.10), and a history of depression (OR, 2.84; 95% CI, 1.69-4.78).

CONCLUSIONS AND RELEVANCE

Expectant fathers were at risk of depression symptoms if they felt stressed or were in poor health. Rates of elevated depression symptoms were higher during the postpartum period and were associated with adverse social and relationship factors. Identifying fathers most at risk of depressive symptoms and when best to target interventions (antenatal or postnatal) may be beneficial to men and their families.

Infant Behavior Questionnaire-Revised Very Short Form: A New Factor Structure's Associations With Parenting Perceptions and Child Language Outcomes

The Infant Behavior Questionnaire Revised-Very Short Form (IBQ-R VSF; Putnam, Helbig, Gartstein, Rothbart, & Leerkes, 2014 ) is a new publicly available measure of infant temperament measuring positive affectivity/surgency (PAS), negative emotionality (NEG), and orienting and regulatory capacity (ORC). Although the initial psychometric properties of the 3-factor model appear promising, it has not been administered to a large and diverse sample and its predictive validity has not been established. This study administered the IBQ-R VSF to a diverse sample of 5,639 mothers of infants aged between 23 and 52 weeks. Confirmatory factor analysis found that the 3-factor solution did not meet the requirement for satisfactory model fit. Exploratory factor analysis found that a 5-factor solution (PAS, NEG, Orienting Capacity, Affiliation/Regulation, and Fear) was statistically and conceptually the most parsimonious. All 5 temperament dimensions were found to relate to both mother- and partner-reported infant closeness, parenting confidence, and parenting satisfaction, and four of the dimensions (PAS, Orienting Capacity, NEG, and Fear) related to the infants' communication development. Some parental differences were also found. Together these findings suggest that the 5-factor IBQ-R VSF is a promising measure of infant temperament and is related to parenting perceptions and child language development.

A Cross-Cultural Analysis of the Infant Behavior Questionnaire Very Short Form: An Item Response Theory Analysis of Infant Temperament in New Zealand

The Infant Behavior Questionnaire-Revised Very Short Form (IBQ-R VSF; Putnam, Helbig, Gartstein, Rothbart, & Leerkes, 2014 ) is a newly published measure of infant temperament with a 3-factor structure. Recently Peterson et al. ( 2017 ) suggested that a 5-factor structure (Positive Affectivity/Surgency, Negative Emotionality, Orienting Capacity, Affiliation/Regulation, and Fear) was more parsimonious and showed promising reliability and predictive validity in a large, diverse sample. However, little is known about the 5-factor model's precision across the temperament dimensions range and whether it discriminates equally well across ethnicities. A total of 5,567 mothers responded to the IBQ-R VSF in relation to their infants (N = 5,639) between 23 and 52 weeks old. Using item response theory, we conducted a series of 2 parameter logistic item response models and found that 5 IBQ-R VSF temperament dimensions showed a good distribution of estimates across each latent trait range and these estimates centered close to the population mean. The IBQ-R VSF was also similarly precise across 4 ethnic groups (European, Māori, Pacific peoples, and Asians), suggesting that it can be used as comparable measure for infant temperament in a diversity of ethnic groups.

Antibiotics in the first year of life and subsequent neurocognitive outcomes

AIM

There may be a link between disruption to the gut microbiota in early life and later neurocognitive outcomes. We hypothesised that antibiotic use in early life is associated with a detrimental effect on later neurocognitive outcomes.

METHODS

Eight hundred and seventy-one European mothers and their children enrolled in the Auckland Birthweight Collaborative Study at birth. Information on antibiotic use during the first year of life and between 12 months and three-and-a-half years of age was gathered via maternal interview. Intelligence test scores and measures of behavioural difficulties were obtained when children were three-and-a-half years, seven years and 11 years of age.

RESULTS

Antibiotic use in the first year of life was reported in 70% of the 526 children with antibiotic data assessed at age three-and-a-half years. Those who had received antibiotics had more behavioural difficulties and more symptoms of depression at follow-up. Results were consistent across all standardised psychologist administered tests, as well as parent rated, teacher rated and self-report measures.

CONCLUSION

This study demonstrates an association between antibiotic use in the first year of life and subsequent neurocognitive outcomes in childhood. If confirmed by further research, these findings could have implications for the use of antibiotics for minor illnesses in infancy.

Dietary intakes in children born small for gestational age and appropriate for gestational age: A longitudinal study

Children born small for gestational age (SGA) have an increased risk of cardiovascular disease (CVD) and associated risk factors in later life; however, little is known about their dietary intakes. The objective of this study was to assess dietary intakes in SGA and appropriate for gestational age (AGA) at 3.5, 7, and 11 years. The Auckland Birthweight Collaborative Study is a longitudinal case-control study of children born at term (n = 871). Children were assessed at 3.5 (n = 550), 7 (n = 591), and 11 (n = 620) years of age. Diet was assessed using a 24-hr record-assisted recall. Reported dietary intakes were analyzed and compared with the Australian and New Zealand Nutrient Reference Values. Compared with AGA, median energy intakes were significantly lower in SGA at 3.5 years (4.2 MJ [IQR, 3.0 to 5.8] vs. 5.4 MJ [IQR, 3.9 to 6.5]; p < .0001) but not at 7 and 11 years. Inadequate dietary intakes of micronutrients were more prevalent among SGA at 3.5 years and 11 years of age. A large proportion of SGA and AGA children consumed more than the recommended amounts of saturated fats, sugars, and sodium. There was no association of dietary intake and socio-demographic factors. This study reveals that dietary intake in 3.5-year-old children born SGA is lower in energy and a variety of micronutrients compared with dietary intake in AGA. These intakes may however be appropriate given their BMI z-scores. High intakes of sodium, saturated fat, and sugars are a concern for all children in this cohort.

Associations Between the KIAA0319 Dyslexia Susceptibility Gene Variants, Antenatal Maternal Stress, and Reading Ability in a Longitudinal Birth Cohort

Maternal stress during pregnancy has been associated with detrimental cognitive developmental outcomes in offspring. This study investigated whether antenatal maternal perceived stress and variants of the rs12193738 and rs2179515 polymorphisms on the KIAA0319 gene interact to affect reading ability and full-scale IQ (FSIQ) in members of the longitudinal Auckland Birthweight Collaborative study. Antenatal maternal stress was measured at birth, and reading ability was assessed at ages 7 and 16. Reading data were available for 500 participants at age 7 and 479 participants at age 16. FSIQ was measured at ages 7 and 11. At age 11, DNA samples were collected. Analyses of covariance revealed that individuals with the TT genotype of the rs12193738 polymorphism exposed to high maternal stress during pregnancy possessed significantly poorer reading ability (as measured by Woodcock-Johnson Word Identification standard scores) during adolescence compared with TT carriers exposed to low maternal stress. TT carriers of the rs12193738 SNP also obtained lower IQ scores at age 7 than C allele carriers. These findings suggest that the KIAA0319 gene is associated with both reading ability and general cognition, but in different ways. The effect on IQ appears to occur earlier in development and is transient, whereas the effect of reading ability occurs later and is moderated by antenatal maternal stress. Copyright © 2016 John Wiley & Sons, Ltd.

Catechol-O-methyltransferase val(158)met Polymorphism Interacts with Sex to Affect Face Recognition Ability

The catechol-O-methyltransferase (COMT) val158met polymorphism affects the breakdown of synaptic dopamine. Consequently, this polymorphism has been associated with a variety of neurophysiological and behavioral outcomes. Some of the effects have been found to be sex-specific and it appears estrogen may act to down-regulate the activity of the COMT enzyme. The dopaminergic system has been implicated in face recognition, a form of cognition for which a female advantage has typically been reported. This study aimed to investigate potential joint effects of sex and COMT genotype on face recognition. A sample of 142 university students was genotyped and assessed using the Faces I subtest of the Wechsler Memory Scale - Third Edition (WMS-III). A significant two-way interaction between sex and COMT genotype on face recognition performance was found. Of the male participants, COMT val homozygotes and heterozygotes had significantly lower scores than met homozygotes. Scores did not differ between genotypes for female participants. While male val homozygotes had significantly lower scores than female val homozygotes, no sex differences were observed in the heterozygotes and met homozygotes. This study contributes to the accumulating literature documenting sex-specific effects of the COMT polymorphism by demonstrating a COMT-sex interaction for face recognition, and is consistent with a role for dopamine in face recognition.

Environmental and genetic determinants of childhood depression: The roles of DAT1 and the antenatal environment

Research on adolescent and adult populations has linked depression to variation in several monoaminergic genes, but genetic association studies on depression in children are limited. Additionally, few studies have investigated whether stressors occurring very early in development moderate the influence of certain genes on depression. The aim of this study was to investigate whether single nucleotide polymorphisms (SNPs) from monoaminergic genes interacted with measures of early life stress to influence depressive symptoms in children. Participants were members of the Auckland Birthweight Collaborative cohort. Small for gestational age (SGA) and maternal stress during pregnancy were measured at birth and used as indicators of early life stress. At age 11, depressive symptoms were measured using the Centre for Epidemiological Studies Depression Scale for Children (CES-DC) and DNA samples were collected for genotyping. A two-way ANOVA revealed that SGA and a SNP from the dopamine transporter gene DAT1 had an interactive effect on children's depressive symptoms. Specifically, symptoms were greater in children born SGA who are T homozygous for the rs1042098 SNP. These findings suggest that adverse intrauterine environments leading to low birth weight also seem to exacerbate the effects of certain DAT1 variants on depression.

Seven Pervasive Statistical Flaws in Cognitive Training Interventions

The prospect of enhancing cognition is undoubtedly among the most exciting research questions currently bridging psychology, neuroscience, and evidence-based medicine. Yet, convincing claims in this line of work stem from designs that are prone to several shortcomings, thus threatening the credibility of training-induced cognitive enhancement. Here, we present seven pervasive statistical flaws in intervention designs: (i) lack of power; (ii) sampling error; (iii) continuous variable splits; (iv) erroneous interpretations of correlated gain scores; (v) single transfer assessments; (vi) multiple comparisons; and (vii) publication bias. Each flaw is illustrated with a Monte Carlo simulation to present its underlying mechanisms, gauge its magnitude, and discuss potential remedies. Although not restricted to training studies, these flaws are typically exacerbated in such designs, due to ubiquitous practices in data collection or data analysis. The article reviews these practices, so as to avoid common pitfalls when designing or analyzing an intervention. More generally, it is also intended as a reference for anyone interested in evaluating claims of cognitive enhancement.

Associations between schizotypy and cerebral laterality

Atypical lateralization for language has been found in schizophrenia, suggesting that language and thought disorders on the schizophrenia spectrum may be due to left hemispheric dysfunction. However, research with those with non-clinical schizotypy has been inconsistent, with some studies finding reduced or reversed language laterality (particularly with positive schizotypal traits), and others finding typical left hemispheric specialization. The aim of the current study was to use both a behavioural (dual reading-finger tapping) task and an functional magnetic resonance imaging lexical decision task to investigate language laterality in a university sample of high- and low-schizotypal adults. Findings revealed no evidence for atypical lateralization in our sample for both overall schizotypy (measured by the Oxford-Liverpool Inventory of Feelings and Experiences) and positive schizotypy (measured by the Unusual Experiences subscale) groups. Our findings provide further evidence that non-clinical schizotypy is not associated with atypical language laterality.

Developmental Learning Disorders: From Generic Interventions to Individualized Remediation

Developmental learning disorders affect many children, impairing their experience in the classroom and hindering many aspects of their life. Once a bleak sentence associated with life-long difficulties, several learning disorders can now be successfully alleviated, directly benefiting from promising interventions. In this review, we focus on two of the most prevalent learning disorders, dyslexia and attention-deficit/hyperactivity disorder (ADHD). Recent advances have refined our understanding of the specific neural networks that are altered in these disorders, yet questions remain regarding causal links between neural changes and behavioral improvements. After briefly reviewing the theoretical foundations of dyslexia and ADHD, we explore their distinct and shared characteristics, and discuss the comorbidity of the two disorders. We then examine current interventions, and consider the benefits of approaches that integrate remediation within other activities to encourage sustained motivation and improvements. Finally, we conclude with a reflection on the potential for remediation programs to be personalized by taking into account the specificities and demands of each individual. The effective remediation of learning disorders is critical to modern societies, especially considering the far-reaching ramifications of successful early interventions.

Distinguishing autism from co-existing conditions: a behavioural profiling investigation

Purpose

– Autism spectrum disorder (ASD) is a lifelong neurodevelopmental condition for which there is no known cure. The rate of psychiatric comorbidity in autism is extremely high, which raises questions about the nature of the co-occurring symptoms. It is unclear whether these additional conditions are true comorbid conditions, or can simply be accounted for through the ASD diagnosis. The paper aims to discuss this issue.

Design/methodology/approach

– A number of questionnaires and a computer-based task were used in the current study. The authors asked the participants about symptoms of ASD, attention deficit hyperactivity disorder (ADHD) and anxiety, as well as overall adaptive functioning.

Findings

– The results demonstrate that each condition, in its pure form, can be clearly differentiated from one another (and from neurotypical controls). Further analyses revealed that when ASD occurs together with anxiety, anxiety appears to be a separate condition. In contrast, there is no clear behavioural profile for when ASD and ADHD co-occur.

Research limitations/implications

– First, due to small sample sizes, some analyses performed were targeted to specific groups (i.e. comparing ADHD, ASD to comorbid ADHD+ASD). Larger sample sizes would have given the statistical power to perform a full scale comparative analysis of all experimental groups when split by their comorbid conditions. Second, males were over-represented in the ASD group and females were over-represented in the anxiety group, due to the uneven gender balance in the prevalence of these conditions. Lastly, the main profiling techniques used were questionnaires. Clinical interviews would have been preferable, as they give a more objective account of behavioural difficulties.

Practical implications

– The rate of psychiatric comorbidity in autism is extremely high, which raises questions about the nature of the co-occurring symptoms. It is unclear whether these additional conditions are true comorbid conditions, or can simply be accounted for through the ASD diagnosis.

Social implications

– This information will be important, not only to healthcare practitioners when administering a diagnosis, but also to therapists who need to apply evidence-based treatment to comorbid and stand-alone conditions.

Originality/value

– This study is the first to investigate the nature of co-existing conditions in ASD in a New Zealand population.

Depression symptoms during pregnancy: Evidence from Growing Up in New Zealand

BACKGROUND

Depression during pregnancy has significant implications for pregnancy outcomes and maternal and child health. There is a need to identify which family, physical and mental health factors are associated with depression during pregnancy.

METHODS

An ethnically and socioeconomically diverse sample of 5664 pregnant women living in New Zealand completed a face-to-face interview during the third trimester. Antenatal depression (AD) symptoms were assessed using the Edinburgh Postnatal Depression Scale (EPDS). Maternal demographic, physical and mental health, and family and relationship characteristics were measured. The association between symptoms of AD and maternal characteristics was determined using multiple logistic regression.

RESULTS

11.9% of the participating women had EPDS scores (13+) that indicated probable AD. When considering sociodemographic predictors of AD symptoms, we found that women from non-European ethnicities, specifically Pacific Islander, Asian and other, were more likely to suffer from AD symptoms. Greater perceived stress during pregnancy and a diagnosis of anxiety both before and during pregnancy were also associated with greater odds of having AD according to the EPDS.

LIMITATIONS

The women were in their third trimester of pregnancy at the interview. Therefore, we cannot discount the possibility of recall bias for questions relating to pre-pregnancy status or early-pregnancy behaviours.

CONCLUSIONS

AD is prevalent amongst New Zealand women. Ethnicity, perceived stress and anxiety are particularly associated with a greater likelihood of depression during pregnancy. Further attention to supporting maternal mental health status in the antenatal period is required.

The brain-derived neurotrophic factor (BDNF) val66met polymorphism differentially affects performance on subscales of the Wechsler Memory Scale - Third Edition (WMS-III)

Single nucleotide polymorphisms in the brain-derived neurotrophic factor (BDNF) gene and the catechol-O-methyltransferase (COMT) gene influence brain structure and function, as well as cognitive abilities. They are most influential in the hippocampus and prefrontal cortex (PFC), respectively. Recall and recognition are forms of memory proposed to have different neural substrates, with recall having a greater dependence on the PFC and hippocampus. This study aimed to determine whether the BDNF val⁶⁶met or COMT val¹⁵⁸met polymorphisms differentially affect recall and recognition, and whether these polymorphisms interact. A sample of 100 healthy adults was assessed on recall and familiarity-based recognition using the Faces and Family Pictures subscales of the Wechsler Memory Scale – Third Edition (WMS-III). COMT genotype did not affect performance on either task. The BDNF polymorphism (i.e., met carriers relative to val homozygotes) was associated with poorer recall ability, while not influencing recognition. Combining subscale scores in memory tests such as the WMS might obscure gene effects. Our results demonstrate the importance of distinguishing between recall and familiarity-based recognition in neurogenetics research.

Neural correlates of creative thinking and schizotypy

Empirical studies indicate a link between creativity and schizotypal personality traits, where individuals who score highly on schizotypy measures also display greater levels of creative behaviour. However, the exact nature of this relationship is not yet clear, with only a few studies examining this association using neuroimaging methods. In the present study, the neural substrates of creative thinking were assessed with a drawing task paradigm in healthy individuals using fMRI. These regions were then statistically correlated with the participants' level of schizotypy as measured by the Oxford-Liverpool Inventory of Feelings and Experiences (O-LIFE), which is a questionnaire consisting of four dimensions. Neural activations associated with the creativity task were observed in bilateral inferior temporal gyri, left insula, left parietal lobule, right angular gyrus, as well as regions in the prefrontal cortex. This widespread pattern of activation suggests that creative thinking utilises multiple neurocognitive networks, with creative production being the result of collaboration between these regions. Furthermore, the correlational analyses found the Unusual Experiences factor of the O-LIFE to be the most common dimension associated with these areas, followed by the Impulsive Nonconformity dimension. These correlations were negative, indicating that individuals who scored the highest in these factors displayed the least amount of activation when performing the creative task. This is in line with the idea that 'less is more' for creativity, where the deactivation of specific cortical areas may facilitate creativity. Thus, these findings contribute to the evidence of a common neural basis between creativity and schizotypy.

Brain-derived neurotrophic factor Val66Met polymorphism, human memory, and synaptic neuroplasticity

Some people have much better memory than others, and there is compelling evidence that a considerable proportion of this variation in memory ability is genetically inherited. A form of synaptic plasticity known as long-term potentiation (LTP) is the principal candidate mechanism underlying memory formation in neural circuits, and it might be expected, therefore, that a genetic influence on the degree of LTP might in turn influence memory abilities. Of the genetic variations thought to significantly influence mnemonic ability in humans, the most likely to have its effect via LTP is a single nucleotide polymorphism affecting brain-derived neurotrophic factor [BDNF (Val66Met)]. However, although it is likely that BDNF influences memory via a modulation of acute plasticity (i.e., LTP), BDNF also has considerable influence on structural development of neural systems. Thus, the influence of BDNF (Val66Met) on mnemonic performance via influences of brain structure as well as function must also be considered. In this brief review, we will describe the phenomenon of LTP and its study in non-human animals. We will discuss the relatively recent attempts to translate this work to studies in humans. We will describe how this has enabled investigation of the effect of the BDNF polymorphism on LTP, on brain structure, and on memory performance.