Breastfeeding and early brain development: the Generation R study

Breastfeeding during infancy is associated with a range of short- and long-term health benefits. We examine whether breastfeeding in the first 2 months of life is associated with structural markers of brain development in infants from the general population. This study was embedded within the Generation R study. Cranial ultrasounds were obtained at approximately 7 weeks post-natal age. The diameter of the gangliothalamic ovoid, corpus callosum length, ventricular volume and head circumference were measured. Maternal reports of breastfeeding were obtained at 2 months of age. We examined associations in relation to current breastfeeding practices (exclusively breastfed, n = 318, breast- and bottle-fed, n = 119, and bottle-fed, n = 243). Analyses were adjusted for head size and relevant covariates. Secondary analyses were conducted for breastfeeding history (exclusively breastfed, n = 318, breast- and bottle-fed, n = 281, and never breastfed, n = 81). Exclusive breastfeeding was associated with more optimal brain development compared with babies who were bottle-fed or never breastfed. Results were most consistent for gangliothalamic ovoid diameter. Larger gangliothalamic ovoid diameters were evident in babies who were exclusively breastfed compared with bottle-fed babies [difference between means (95% confidence interval) = 0.21(0.02, 0.39), P = 0.02]. Smaller ventricular volume and larger head circumference were also found for exclusively breastfed babies. Breastfeeding was not significantly associated with corpus callosum length. Maternal reports of breastfeeding are associated with more mature brain development within the first 2 months of life. Results are most consistent for gangliothalamic ovoid diameter, a subcortical structure rich in docosahexaenoic acid. Findings also pointed to non-specific neural developmental advantage for exclusively breastfed babies.

Trajectories of psychosocial problems in adolescents predicted by findings from early well-child assessments

PURPOSE

To describe trajectories of emotional and behavioral problems in adolescents and to identify early indicators of these trajectories using data from routine well-child assessments at ages 0-4 years.

METHODS

Data from three assessment waves of adolescents (n = 1,816) of the TRAILS were used (ages: 11-17 years). Information on early indicators (at ages 0-4 years) came from the records of the well-child services. Trajectories of emotional and behavioral problems were based on the parent-reported Child Behavior Checklist and the adolescent-reported Youth Self-Report, filled out at ages 11, 14, and 17 years. Multinomial logistic regression analysis was used to examine the predictive value of these early indicators on trajectories.

RESULTS

For boys and girls, we found four trajectories for each outcome: one with high problem levels, and three with middle-high, middle-low, and low levels. For emotional problems, the type of trajectory was predicted by parental educational level and parental divorce or single parents, for both genders. Moreover, sleep problems were predictive in boys and language problems in girls (odds ratios between 1.53 and 7.42). For behavioral problems, the type of trajectory was predicted by maternal smoking during pregnancy, parental educational level, and parental divorce or single parents, for both genders. Moreover, for boys, early behavioral problems and attention hyperactivity problems were predictive (odds ratios between 1.64 and 5.43).

CONCLUSIONS

Trajectories of emotional and behavioral problems during adolescence are rather stable and can be predicted by a parsimonious set of data from early well-child assessments.

Febrile seizures and behavioural and cognitive outcomes in preschool children: the Generation R study

AIM

General developmental outcome is known to be good in school-aged children who experienced febrile seizures. We examined cognitive and behavioural outcomes in preschool children with febrile seizures, including language and executive functioning outcomes.

METHOD

This work was performed in the Generation R Study, a population-based cohort study in Rotterdam from early fetal life onwards. Information about the occurrence of febrile seizures was collected by questionnaires at the ages of 1, 2, and 3 years. At the age of 3 years, behaviour and emotion were assessed using the Child Behavior Checklist. Information on expressive language development was obtained by the Language Development Survey at the age of 2 years 6 months. To assess executive functioning, parents completed the Behaviour Rating Inventory of Executive Function - Preschool Version when their children were 4 years old. Final analyses were based on 3157 children.

RESULTS

No associations were found between febrile seizures and the risk of behavioural problems or executive functioning. In contrast to single febrile seizures, recurrent febrile seizures were significantly associated with an increased risk of delayed vocabulary development (odds ratio 3.22, [95% confidence interval 1.30-7.94]).

INTERPRETATION

Febrile seizures are not associated with problem behaviour or executive functioning in preschool children, but the results suggest that children with recurrent febrile seizures might be at risk for delayed language development.

The Generation R Study: a review of design, findings to date, and a study of the 5-HTTLPR by environmental interaction from fetal life onward

OBJECTIVE

First, we give an overview of child psychiatric research in the Generation R Study, a population-based cohort from fetal life forward. Second, we examine within Generation R whether the functional polymorphism (5-HTTLPR) in the promoter of the serotonin transporter gene interacts with prenatal maternal chronic difficulties, prenatal maternal anxiety or postnatal maternal anxiety to influence child emotional development.

METHOD

A total of 2,136 northern European children were genotyped for 5-HTTLPR and rs25531. Mothers reported chronic difficulties and anxiety symptoms at 20 weeks' pregnancy and when the child was 3 years old. Child emotion recognition was observed at 3 years, and child emotional problems were assessed with the CBCL/1½-5 at 5 years.

RESULTS

There were consistent main effects of maternal difficulties and anxiety on child emotional problems, but no main effect of 5-HTTLPR. Moreover, children with the s allele were at increased risk for emotional problems if their mothers reported prenatal anxiety symptoms (β = 2.02, p < .001) or postnatal anxiety symptoms (β = 1.64, p < 0.001). Also, in children of mothers with prenatal anxiety symptoms, the s allele was associated with less accurate emotion-matching (β = -0.11, p = .004).

CONCLUSIONS

This population-based study shows that vulnerability due to 5-HTTLPR is not specific for certain adverse exposures or severe events, but suggests that the small effects of gene-environment interaction on emotional development become manifest early in life.

Children's eating behavior, feeding practices of parents and weight problems in early childhood: results from the population-based Generation R Study

BACKGROUND

Weight problems that arise in the first years of life tend to persist. Behavioral research in this period can provide information on the modifiable etiology of unhealthy weight. The present study aimed to replicate findings from previous small-scale studies by examining whether different aspects of preschooler's eating behavior and parental feeding practices are associated with body mass index (BMI) and weight status -including underweight, overweight and obesity- in a population sample of preschool children.

METHODS

Cross-sectional data on the Child Eating Behaviour Questionnaire, Child Feeding Questionnaire and objectively measured BMI was available for 4987 four-year-olds participating in a population-based cohort in the Netherlands.

RESULTS

Thirteen percent of the preschoolers had underweight, 8% overweight, and 2% obesity. Higher levels of children's Food Responsiveness, Enjoyment of Food and parental Restriction were associated with a higher mean BMI independent of measured confounders. Emotional Undereating, Satiety Responsiveness and Fussiness of children as well as parents' Pressure to Eat were negatively related with children's BMI. Similar trends were found with BMI categorized into underweight, normal weight, overweight and obesity. Part of the association between children's eating behaviors and BMI was accounted for by parental feeding practices (changes in effect estimates: 20-43%), while children's eating behaviors in turn explained part of the relation between parental feeding and child BMI (changes in effect estimates: 33-47%).

CONCLUSIONS

This study provides important information by showing how young children's eating behaviors and parental feeding patterns differ between children with normal weight, underweight and overweight. The high prevalence of under- and overweight among preschoolers suggest prevention interventions targeting unhealthy weights should start early in life. Although longitudinal studies are necessary to ascertain causal directions, efforts to prevent or treat unhealthy child weight might benefit from a focus on changing the behaviors of both children and their parents.

The Generation R Study: design and cohort update 2012

The Generation R Study is a population-based prospective cohort study from fetal life until adulthood. The study is designed to identify early environmental and genetic causes and causal pathways leading to normal and abnormal growth, development and health during fetal life, childhood and adulthood. The study focuses on six areas of research: (1) maternal health; (2) growth and physical development; (3) behavioural and cognitive development; (4) respiratory health and allergies; (5) diseases in childhood; and (6) health and healthcare for children and their parents. Main exposures of interest include environmental, endocrine, genetic and epigenetic, lifestyle related, nutritional and socio-demographic determinants. In total, n = 9,778 mothers with a delivery date from April 2002 until January 2006 were enrolled in the study. Response at baseline was 61 %, and general follow-up rates until the age of 6 years exceed 80 %. Data collection in mothers, fathers and children include questionnaires, detailed physical and ultrasound examinations, behavioural observations, and biological samples. A genome and epigenome wide association screen is available in the participating children. From the age of 5 years, regular detailed hands-on assessments are performed in a dedicated research center including advanced imaging facilities such as Magnetic Resonance Imaging. Eventually, results forthcoming from the Generation R Study contribute to the development of strategies for optimizing health and healthcare for pregnant women and children.

Increased risk of exceeding entertainment-media guidelines in preschool children from low socioeconomic background: the Generation R Study

OBJECTIVE

To describe and explain the association between maternal educational level and television viewing time among preschool children.

METHOD

We analyzed data from 2786 preschoolers enrolled in a birth cohort study in Rotterdam, The Netherlands, between 2002 and 2006. Odds ratios of watching television ≥2 hours/day and ≥1 hour/day were calculated for children of mothers with low, mid-low, and mid-high educational level (reference group: high educational level), before and after adjustment for mediators.

RESULTS

Children of low, mid-low, and mid-high educated mothers were more likely to watch television ≥2 hours/day compared to children of high educated mothers, with children of low educated mother showing the highest risk (OR: 11.32; 95% CI: 6.58, 19.46). Adjustment for mediators (i.e. maternal body mass index, parental television viewing, presence of a television set in the child's bedroom, and financial difficulties) led to a nearly 50% reduction in odds ratio for the lowest educational group (OR: 6.61; 95% CI: 3.69, 11.84). A similar educational gradient was found for watching television ≥1 hour/day, although effect estimates were smaller.

CONCLUSION

Maternal education is inversely associated with preschoolers' television viewing time. This association was partly explained by known correlates of children's television viewing.

The TRacking Adolescents' Individual Lives Survey (TRAILS): design, current status, and selected findings

OBJECTIVES

The objectives of this study were as follows: to present a concise overview of the sample, outcomes, determinants, non-response and attrition of the ongoing TRacking Adolescents' Individual Lives Survey (TRAILS), which started in 2001; to summarize a selection of recent findings on continuity, discontinuity, risk, and protective factors of mental health problems; and to document the development of psychopathology during adolescence, focusing on whether the increase of problem behavior often seen in adolescence is a general phenomenon or more prevalent in vulnerable teens, thereby giving rise to diverging developmental pathways.

METHOD

The first and second objectives were achieved using descriptive statistics and selective review of previous TRAILS publications; and the third objective by analyzing longitudinal data on internalizing and externalizing problems using Linear Mixed Models (LMM).

RESULTS

The LMM analyses supported the notion of diverging pathways for rule-breaking behaviors but not for anxiety, depression, or aggression. Overall, rule-breaking (in both genders) and withdrawn/depressed behavior (in girls) increased, whereas aggression and anxious/depressed behavior decreased during adolescence.

CONCLUSIONS

TRAILS has produced a wealth of data and has contributed substantially to our understanding of mental health problems and social development during adolescence. Future waves will expand this database into adulthood. The typical development of problem behaviors in adolescence differs considerably across both problem dimensions and gender. Developmental pathways during adolescence suggest accumulation of risk (i.e., diverging pathways) for rule-breaking behavior. However, those of anxiety, depression and aggression slightly converge, suggesting the influence of counter-forces and changes in risk unrelated to initial problem levels and underlying vulnerability.

Ethnic differences in problem perception and perceived need for care for young children with problem behaviour

BACKGROUND

 Problem perception and perceived need for professional care are important determinants that can contribute to ethnic differences in the use of mental health care. Therefore, we studied ethnic differences in problem perception and perceived need for professional care in the parents and teachers of 5- to 6-year-old children from the general population who were selected for having emotional and behavioural problems.

METHODS

A cross-sectional study with data of 10,951 children from grade two of the elementary schools in the Rotterdam-Rijnmond area, The Netherlands. Parents and teachers completed the strengths and difficulties questionnaire (SDQ) as well as questions on problem perception and perceived need for care. The SDQ was used to identify children with emotional and behavioural problems. We included Dutch, Surinamese, Antillean, Moroccan and Turkish children in our sample with high (>P90) SDQ scores (N = 1,215), who were not currently receiving professional care for their problems.

RESULTS

Amongst children with high SDQ scores, problem perception was lower in non-Dutch parents than in Dutch parents (49% vs. 81%, p < 0.01). These lower rates of problem perception could not be explained by differences in socioeconomic position or severity of the problems. No ethnic differences were found in parental perceived need and in problem perception and perceived need reported by teachers. Higher levels of problem perception and perceived need were reported by teachers than by parents in all ethnic groups (PP: 87% vs. 63% and PN: 48% vs. 23%).

CONCLUSIONS

Child health professionals should be aware of ethnic variations in problem perception as low problem perception in parents of non-Dutch children may lead to miscommunication and unmet need for professional care for the child.

Early trauma and familial risk in the development of the extended psychosis phenotype in adolescence

OBJECTIVE

Both genetic and environmental factors are thought to play a role in the development of psychotic outcomes; however, their respective contributions over time, including possible developmental interactions, remain largely unknown.

METHOD

The contribution of parental general and psychotic psychopathology as proxies of genetic risk to the development of subthreshold psychosis and its hypothesized interaction with childhood trauma were studied in a general population sample of 2230 adolescents, followed from age 10-16 years. Outcome measures were: i) level of psychotic experiences at age 16 years and ii) persistence of such experiences over the total follow-up period.

RESULTS

General parental psychopathology was associated with CAPE score (OR = 1.08; P < 0.043 for highest quintile) and suggestively predicted psychosis persistence (OR, 1.16; P < 0.072). Psychotic parental psychopathology was suggestively associated with CAPE score (OR, 2.25; P < 0.063 for highest quintile), predicted membership of the Persistent group (OR, 3.72; P < 0.039) and suggestively predicted membership of the Decreasing group (OR 2.04; P < 0.051). Childhood trauma was associated with CAPE score and with all developmental trajectories of subclinical psychosis. No evidence was found for an interaction between trauma and parental psychopathology.

CONCLUSION

The development and persistence of subthreshold psychotic symptoms may be conditional on non-interacting proxy genetic and environmental influences.

Variation in the glucocorticoid receptor gene at rs41423247 moderates the effect of prenatal maternal psychological symptoms on child cortisol reactivity and behavior

Prenatal maternal psychopathology affects child development, but some children seem more vulnerable than others. Genetic variance in hypothalamic-pituitary-adrenal axis genes may influence the effect of prenatal maternal psychological symptoms on child emotional and behavioral problems. This hypothesis was tested in the Generation R Study, a population-based cohort from fetal life onward. In total, 1727 children of Northern European descent and their mothers participated in this study and were genotyped for variants in the glucocorticoid receptor (GR) gene (rs6189/rs6190, rs10052957, rs41423247, rs6195, and rs6198) and the FK506-binding protein 5 (FKBP5) gene (rs1360780). Prenatal maternal psychological symptoms were assessed at 20 weeks pregnancy and child behavior was assessed by both parents at 3 years. In a subsample of 331 children, data about cortisol reactivity were available. Based on power calculations, only those genetic variants with sufficient minor allele frequencies (rs41423247, rs10052957, and rs1360780) were included in the interaction analyses. We found that variation in GR at rs41423247 moderates the effect of prenatal maternal psychological symptoms on child emotional and behavioral problems (beta 0.41, SE 0.16, p=0.009). This prenatal interaction effect was independent of mother's genotype and maternal postnatal psychopathology, and not found for prenatal psychological symptoms of the father. Moreover, the interaction between rs41423247 and prenatal psychological symptoms was also associated with decreased child cortisol reactivity (beta -2.30, p-value 0.05). These findings emphasize the potential effect of prenatal gene-environment interaction, and give insight in possible mechanisms accounting for children's individual vulnerability to develop emotional and behavioral problems.

Functional connectivity between parietal and frontal brain regions and intelligence in young children: the Generation R study

It has been shown in adults that individual differences in intelligence are related to the integrity of the interaction between parietal and frontal brain regions. Since connectivity between distant brain regions strengthens during childhood, it is unclear when in the course of development this relationship emerges. Thus, the goal of this study was to determine whether parietal-frontal functional connectivity is associated with intelligence in young children. We performed independent component analyses on resting-state fMRI data of 115 children (6-8 years old) to select seed and target regions for a seed/target region correlation analysis. We found that higher nonverbal intelligence was associated with increased functional connectivity between right parietal and right frontal regions, and between right parietal and dorsal anterior cingulate regions. The association between intelligence and functional connectivity between certain brain regions was stronger in girls than boys. In conclusion, we found that connectivity between the parietal and frontal lobes is critically involved in intelligence in young children.

Puzzling findings in studying the outcome of "real world" adolescent mental health services: the TRAILS study

BACKGROUND

The increased use and costs of specialist child and adolescent mental health services (MHS) urge us to assess the effectiveness of these services. The aim of this paper is to compare the course of emotional and behavioural problems in adolescents with and without MHS use in a naturalistic setting.

METHOD AND FINDINGS

Participants are 2230 (pre)adolescents that enrolled in a prospective cohort study, the TRacking Adolescents' Individual Lives Survey (TRAILS). Response rate was 76%, mean age at baseline 11.09 (SD 0.56), 50.8% girls. We used data from the first three assessment waves, covering a six year period. Multiple linear regression analysis, propensity score matching, and data validation were used to compare the course of emotional and behavioural problems of adolescents with and without MHS use. The association between MHS and follow-up problem score (β 0.20, SE 0.03, p-value<0.001) was not confounded by baseline severity, markers of adolescent vulnerability or resilience nor stressful life events. The propensity score matching strategy revealed that follow-up problem scores of non-MHS-users decreased while the problem scores of MHS users remained high. When taking into account future MHS (non)use, it appeared that problem scores decreased with limited MHS use, albeit not as much as without any MHS use, and that problem scores with continuous MHS use remained high. Data validation showed that using a different outcome measure, multiple assessment waves and multiple imputation of missing values did not alter the results. A limitation of the study is that, although we know what type of MHS participants used, and during which period, we lack information on the duration of the treatment.

CONCLUSIONS

The benefits of MHS are questionable. Replication studies should reveal whether a critical examination of everyday care is necessary or an artefact is responsible for these results.

Maternal use of selective serotonin reuptake inhibitors, fetal growth, and risk of adverse birth outcomes

CONTEXT

Selective serotonin reuptake inhibitors (SSRIs) are frequently prescribed to pregnant women, but knowledge about their unintended effects on child health is scarce.

OBJECTIVE

To examine the effects of maternal SSRI use during pregnancy on fetal growth and birth outcomes.

DESIGN

The study was embedded in the Generation R Study, a prospective population-based study from fetal life onward.

PARTICIPANTS

Seven thousand six hundred ninety-six pregnant women were included. Selective serotonin reuptake inhibitor use was assessed by questionnaires in each trimester and verified by pharmacy records. Using depressive symptom scores from the Brief Symptom Inventory, 7027 pregnant mothers (91.3%) had no or low depressive symptoms, 570 pregnant mothers (7.4%) had clinically relevant depressive symptoms and used no SSRIs, and 99 pregnant mothers (1.3%) used SSRIs.

MAIN OUTCOME MEASURES

Fetal ultrasonography was performed in each trimester. We determined fetal body and head growth with repeated assessments of body and head size. The birth outcomes studied were preterm birth, small for gestational age, and low birth weight.

RESULTS

Fetuses from mothers with prenatal depressive symptoms showed reduced body growth (β=-4.4 g/wk; 95% CI: -6.3 to -2.4; P<.001) and head growth (β=-0.08 mm/wk; 95% CI: -0.14 to -0.03; P=.003). Mothers using SSRIs during pregnancy had fewer depressive symptoms than mothers in the clinical symptom range. Prenatal SSRI use was not associated with reduced body growth but was associated with reduced fetal head growth (β=-0.18 mm/wk; 95% CI: -0.32 to -0.07; P=.003). The SSRI-exposed children were at higher risk for preterm birth (odds ratio=2.14; 95% CI: 1.08 to 4.25; P=.03).

CONCLUSIONS

Untreated maternal depression was associated with slower rates of fetal body and head growth. Pregnant mothers treated with SSRIs had fewer depressive symptoms and their fetuses had no delay in body growth but had delayed head growth and were at increased risk for preterm birth. Further research on the implications of these findings is needed.

Timing matters: long term effects of adversities from prenatal period up to adolescence on adolescents' cortisol stress response. The TRAILS study

OBJECTIVE

Altered cortisol response is a vulnerability marker for a variety of stress-related diseases and psychiatric disorders. Childhood adversity has been shown to modify this response, but evidence is inconsistent. Effects may differ depending on the timing of exposure, or due to the interplay between pre/postnatal adversity and later adversities. The present study examined the influence of adversity during different timeframes (pre/postnatal, ages 0-5, 6-11, 12-13, 14-15 years), and the interaction between pre/postnatal and later adversity on adolescents' cortisol stress response.

METHOD

Four salivary cortisol samples were collected before and after a social stress test in 471 16-year-old adolescents from the longitudinal study TRAILS. Data on pre/postnatal exposure to adversities were obtained from Preventive Child Healthcare records and parental reports, subsequent adversities from parental and self-reports.

RESULTS

Pre/postnatal adversity was associated with increased cortisol reactivity. Adversities during ages 0-5 were not associated with cortisol outcomes. Adversities during ages 6-11 were associated with a high cortisol level, especially in those exposed to pre/postnatal adversity, while adversities during ages 12-13 and 14-15 were associated with a low cortisol level.

CONCLUSIONS

Results highlight the importance to take the timing of stress exposure into account. In addition to programming effects, pre/postnatal adversity interacts with childhood adversity in producing deviant cortisol levels. Puberty may be marked by a transition in how adversities affect the HPA-axis, with cortisol hypersecretion before age 11 and hyposecretion after age 11.

A brief observational instrument for the assessment of infant home environment: development and psychometric testing

The present paper reports on the development and the psychometric properties of a brief observational assessment of home environments for use in large-scale investigations with young infants. We generated observational items conceptually relevant for child development by two methods. First, we adapted the Infant Toddler Home Observation for Measurement of the Environment (IT-HOME) inventory for use in an exclusively observational context. Second, we added new observational items following a review of relevant literature and consulting professionals. The quality of the instrument was first evaluated in a pilot study (n = 926). In our study sample of 3406 families and their children (median age = 3.1 months, range = 1.6-6.0), exploratory factor analysis was used to identify latent constructs, Cronbach's alpha was used as a measure of internal consistency, and convergent validity was evaluated against family socio-demographic characteristics. Inter-observer agreement was investigated in a sub-sample of the respondents (n = 124). The results supported good psychometric properties of the instrument based on: (a) exploratory factor analysis yielding three meaningful latent constructs, (b) Cronbach's alphas ranging from α = 0.66 to α = 0.90, (c) inter-observer agreement ranging from r = 0.75 to r = 0.91, and (d) associations between the instrument and socio-demographic characteristics in the expected direction [e.g. Odds Ratio for low income = 15.24, 95% confidence interval (11.60, 20.01)].

The association of quality of social relations, symptom severity and intelligence with anxiety in children with autism spectrum disorders

Limited quality of social relations, milder symptom severity and higher intelligence were shown to account for higher anxiety levels in autism spectrum disorders. The current study replicated and extended earlier findings by combining these three determinants of anxiety in autism spectrum disorders in one study. The sample consisted of 134 school-aged children with autism spectrum disorders, of whom 58 (43%) had a co-morbid anxiety disorder according to the Diagnostic Interview Schedule for Children-Parent version. In this sample, we tested associations between these determinants and anxiety univariately and multivariately to clarify the unique contribution of all determinants. Since we hypothesized that the association between limited quality of social relations and anxiety would be amplified by low symptom severity and/or high intelligence, we additionally tested for moderating effects. We found that higher anxiety levels were associated with a lower quality of social relations and lower symptom severity. In this mainly high-functioning sample, intelligence was not related to anxiety levels. No moderation effects were found. Since lower quality of social relations and lower symptom severity are associated with higher anxiety levels in children with autism spectrum disorders, therapeutic interventions aimed at reducing anxiety in autism spectrum disorders should pay attention to improving social relations, and presumably children with a lower symptom severity could benefit most from such interventions.

Using the Child Behavior Checklist and the Teacher's Report Form for identification of children with autism spectrum disorders

This study evaluated the ability of the Child Behavior Checklist and the Teacher's Report Form to identify children with autism spectrum disorders (ASD), using a sample of children with ASD (n = 458), referred children without ASD (n = 1109) and children from the general population (n = 999). A ten items ASD scale was constructed using half of the sample and the ability of this scale to discriminate between children with ASD and the other children was tested for the CBCL and the TRF separately and together in the other half of the sample. Using a cut-off score of 8 the combined CBCL/TRF ASD scale demonstrated high predictive values (NPV 95%, PPV 73%) in identifying children with ASD and children in the general population sample. This might be an acceptable percentage of false positives in general screening, considering the chance that these children might have other behavioural, emotional, and developmental problems which also need psychiatric evaluation. In the referred population, using a cut-off of 13, PPV was 49% and NPV was 85%. The high NPV indicates that in a referred population the scale is especially good at identifying children who do not need evaluation with a more ASD-specific instrument.

Persistence of anxiety disorders and concomitant changes in cortisol

In a clinical sample of 116 children and adolescents we studied the relation between the course of an anxiety disorder during treatment and the concomitant changes in cortisol levels. Assessments at baseline, after three months, and at one-year follow-up were performed with the Anxiety Disorders Interview Schedule. When we compared cortisol levels at baseline and one-year follow-up, persistence of the anxiety disorder was associated with both increased daytime cortisol production (F=3.2, p=0.04) and a trend towards a decreased cortisol morning rise (F=2.4, p=0.09). At one-year follow-up daytime cortisol production was lowest in the early remitters (109.7±29.2 h mmol/l), higher in the late remitters (121.0±40.0 h mmol/l) and highest in the non-remitters (131.1±48.9 h mmol/l). Early remitters had the highest cortisol morning rise (1.1±1.5 h mmol/l), followed by the late remitters (0.8±1.8 h mmol/l), the non-remitters had the lowest cortisol morning rise (0.07±1.7 h mmol/l). Persistence of an anxiety disorder may thus lead to changes in HPA-axis functioning, underscoring the importance adequate treatment of anxiety disorders.

Home environments of infants: relations with child development through age 3

BACKGROUND

This study aimed to examine prospective associations of young infants' home environments with expressive vocabulary delay and internalising and externalising problem scores independently of family socioeconomic status (SES) and national origin.

METHODS

Prospective data from fetal life to age 3 were collected in a total of 2711 families participating in the Generation R Study, a longitudinal population-based cohort. Infants' home environments (ie, the learning environment and the physical environment) were assessed exclusively by observation in their first few months of life (mean age=3.38 months, SD=1.17). Internalising and externalising problems were measured at age 1.5 and 3; expressive vocabulary delay was assessed at age 2.5. Family socio-demographic characteristics, including SES variables and national origin, were measured during pregnancy.

RESULTS

Lower quality learning environments of young infants, but not physical environments, were associated with expressive vocabulary delay and more internalising problems in toddlerhood independently of SES and national origin. Associations of SES and national origin with children's outcomes were reduced when the home environmental variables were added to the regression model.

CONCLUSIONS

The current findings suggest that SES and national origin are reflected, to some degree, in the quality of infants' home environments. Some of the possible interpretations of these results are discussed together with their implications for the early identification of children at risk of impaired development.

Benefits of extensive recruitment effort persist during follow-ups and are consistent across age group and survey method. The TRAILS study

Background

Extensive recruitment effort at baseline increases representativeness of study populations by decreasing non-response and associated bias. First, it is not known to what extent increased attrition occurs during subsequent measurement waves among subjects who were hard-to-recruit at baseline and what characteristics the hard-to-recruit dropouts have compared to the hard-to-recruit retainers. Second, it is unknown whether characteristics of hard-to-recruit responders in a prospective population based cohort study are similar across age group and survey method.

Methods

First, we compared first wave (T1) easy-to-recruit with hard-to-recruit responders of the TRacking Adolescents’ Individual Lives Survey (TRAILS), a prospective population based cohort study of Dutch (pre)adolescents (at first wave: n = 2230, mean age = 11.09 (SD 0.56), 50.8% girls), with regard to response rates at subsequent measurement waves. Second, easy-to-recruit and hard-to-recruit participants at the fourth TRAILS measurement wave (n = 1881, mean age = 19.1 (SD 0.60), 52.3% girls) were compared with fourth wave non-responders and earlier stage drop-outs on family composition, socioeconomic position (SEP), intelligence (IQ), education, sociometric status, substance use, and psychopathology.

Results

First, over 60% of the hard-to-recruit responders at the first wave were retained in the sample eight years later at the fourth measurement wave. Hard-to-recruit dropouts did not differ from hard-to-recruit retainers. Second, extensive recruitment efforts for the web based survey convinced a population of nineteen year olds with similar characteristics as the hard-to-recruit eleven year olds that were persuaded to participate in a school-based survey. Some characteristics associated with being hard-to-recruit (as compared to being easy-to-recruit) were more pronounced among non-responders, resembling the baseline situation (De Winter et al.2005).

Conclusions

First, extensive recruitment effort at the first assessment wave of a prospective population based cohort study has long lasting positive effects. Second, characteristics of hard-to-recruit responders are largely consistent across age groups and survey methods.

Prevalence of bullying and victimization among children in early elementary school: do family and school neighbourhood socioeconomic status matter?

BACKGROUND

Bullying and victimization are widespread phenomena in childhood and can have a serious impact on well-being. Children from families with a low socioeconomic background have an increased risk of this behaviour, but it is unknown whether socioeconomic status (SES) of school neighbourhoods is also related to bullying behaviour. Furthermore, as previous bullying research mainly focused on older children and adolescents, it remains unclear to what extent bullying and victimization affects the lives of younger children. The aim of this study is to examine the prevalence and socioeconomic disparities in bullying behaviour among young elementary school children.

METHODS

The study was part of a population-based survey in the Netherlands. Teacher reports of bullying behaviour and indicators of SES of families and schools were available for 6379 children aged 5-6 years.

RESULTS

One-third of the children were involved in bullying, most of them as bullies (17%) or bully-victims (13%), and less as pure victims (4%). All indicators of low family SES and poor school neighbourhood SES were associated with an increased risk of being a bully or bully-victim. Parental educational level was the only indicator of SES related with victimization. The influence of school neighbourhood SES on bullying attenuated to statistical non-significance once adjusted for family SES.

CONCLUSIONS

Bullying and victimization are already common problems in early elementary school. Children from socioeconomically disadvantaged families, rather than children visiting schools in disadvantaged neighbourhoods, have a particularly high risk of involvement in bullying. These findings suggest the need of timely bullying preventions and interventions that should have a special focus on children of families with a low socioeconomic background. Future studies are necessary to evaluate the effectiveness of such programs.