Preschool family irregularity and the development of sleep problems in childhood: a longitudinal study.

Background: Previous studies have shown that poor family environments are related to more sleep problems; however, little is known about how family irregularity in early life affects the development of sleep problems over childhood using objective sleep measures. The current study tests the hypothesis that early family irregularity contributes to the development of sleep problems.

Methods: This population-based study comprises 5,443 children from the Generation R Study.

During day and night: Childhood psychotic experiences and objective and subjective sleep problems.

Background: Psychotic experiences comprise auditory and visual perceptive phenomena, such as hearing or seeing things that are not there, in the absence of a psychotic disorder. Psychotic experiences commonly occur in the general pediatric population. Although the majority of psychotic experiences are transient, they are predictive of future psychotic and non-psychotic disorders.

The dopamine D4 receptor gene, birth weight, maternal depression, maternal attention, and the prediction of disorganized attachment at 36 months of age: A prospective gene×environment analysis.

Background: Efforts to understand the developmental pathways for disorganized attachment reflect the importance of disorganized attachment on the prediction of future psychopathology. The inconsistent findings on the prediction of disorganized attachment from the dopamine D4 receptor (DRD4) gene, birth weight, and maternal depression as well as the evidence supporting the contribution of early maternal care, suggest the importance of exploring a gene by environment model.

Methods: Our sample is from the Maternal Adversity, Vulnerability, and Neurodevelopment project; consisting of 655 mother-child dyads.

Changes in face-specific neural processing explain reduced cuteness and approachability of infants with cleft lip.

The current study investigated whether changes in the neural processing of faces of infants with a facial abnormality - a cleft lip - mediate effects of the cleft lip on judgments of infant cuteness and approachability. Event-related potentials (ERPs) in response to pictures of faces of healthy infants and infants with a cleft lip, and ratings of cuteness and approachability of these infant faces, were obtained from 30 females. Infants with a cleft lip were rated as less attractive (less cute and approachable) than healthy infants, and both the N170 and P2 components of the ERP were of reduced amplitude in response to pictures of infants with a cleft lip.

Mild perinatal adversities moderate the association between maternal harsh parenting and hair cortisol: Evidence for differential susceptibility.

It has been shown that following exposure to mild perinatal adversity, children have greater susceptibility to both the negative and positive aspects of their subsequent environment. In a large population-based cohort study (N = 1,776), we investigated whether mild perinatal adversity moderated the association between maternal harsh parenting and children's hair cortisol levels, a biomarker of chronic stress. Mild perinatal adversity was defined as late preterm birth (gestational age at birth of 34-37 weeks, 6 days) or small for gestational age (birth weight between the 2.

Heritability and Genome-Wide Association Analyses of Sleep Duration in Children: The EAGLE Consortium.

Study Objectives: Low or excessive sleep duration has been associated with multiple outcomes, but the biology behind these associations remains elusive. Specifically, genetic studies in children are scarce. In this study, we aimed to: (1) estimate the proportion of genetic variance of sleep duration in children attributed to common single nucleotide polymorphisms (SNPs), (2) identify novel SNPs associated with sleep duration in children, and (3) investigate the genetic overlap of sleep duration in children and related metabolic and psychiatric traits.

Beyond main effects of gene-sets: harsh parenting moderates the association between a dopamine gene-set and child externalizing behavior.

Background: In a longitudinal cohort study, we investigated the interplay of harsh parenting and genetic variation across a set of functionally related dopamine genes, in association with children's externalizing behavior. This is one of the first studies to employ gene-based and gene-set approaches in tests of Gene by Environment (G × E) effects on complex behavior. This approach can offer an important alternative or complement to candidate gene and genome-wide environmental interaction (GWEI) studies in the search for genetic variation underlying individual differences in behavior.

Parent-child bed-sharing: The good, the bad, and the burden of evidence.

The practice of parent and child sharing a sleeping surface, or 'bed-sharing', is one of the most controversial topics in parenting research. The lay literature has popularized and polarized this debate, offering on one hand claims of dangers, and on the other, of benefits - both physical and psychological - associated with bed-sharing. To address the scientific evidence behind such claims, we systematically reviewed 659 published papers (peer-reviewed, editorial pieces, and commentaries) on the topic of parent-child bed-sharing.

ASSOCIATION BETWEEN INFANT NIGHTTIME-SLEEP LOCATION AND ATTACHMENT SECURITY: NO EASY VERDICT.

We tested whether mother-infant bed-sharing is associated with increased secure infant-mother attachment, a previously unexplored association. Frequency of bed-sharing and mothers' nighttime comforting measures at 2 months were assessed with questionnaires in 550 Caucasian mothers from a population-based cohort. Attachment security was assessed with the Strange Situation Procedure (M.

Single Nucleotide Polymorphism Heritability of Behavior Problems in Childhood: Genome-Wide Complex Trait Analysis.

Objective: Genetic factors contribute to individual differences in behavior problems. In children, genome-wide association studies (GWAS) have yielded the first suggestive results when aiming to identify genetic variants that explain heritability, but the proportion of genetic variance that can be attributed to common single nucleotide polymorphisms (SNPs) remains to be determined, as only a few studies have estimated SNP heritability, with diverging results.

Method: Genomic-relationship-matrix restricted maximum likelihood (GREML) as implemented in the software Genome-Wide Complex Trait Analysis (GCTA) was used to estimate SNP heritability (SNP h(2)) for multiple phenotypes within 4 broad domains of children's behavioral problems (attention-deficit/hyperactivity symptoms, internalizing, externalizing, and pervasive developmental problems) and cognitive function.

The magnificent seven: A quantitative review of dopamine receptor d4 and its association with child behavior.

A large volume of behavioral research has explored the variable number of tandem repeat (VNTR) polymorphism on the dopamine receptor D4 gene (DRD4). However, findings are inconsistent and there is no agreement about what constitutes "functional" and "less functional" variants at this locus. First, we systematically review studies exploring biological differences between DRD4 VNTRs (k=21).

A genome-wide approach to children's aggressive behavior: The EAGLE consortium.

Individual differences in aggressive behavior emerge in early childhood and predict persisting behavioral problems and disorders. Studies of antisocial and severe aggression in adulthood indicate substantial underlying biology. However, little attention has been given to genome-wide approaches of aggressive behavior in children.

Preschool children without 7-repeat DRD4 gene more likely to develop disorganized attachment style.

Background: The current paper aimed to explore the effects of birth weight and the 7-repeat allele in Exon III of the dopamine D4 receptor (DRD4) gene on the development of disorganized attachment, a potential endophenotype of depression. Infants born with low birth weight have been shown to be at higher risk for later neurological impairments, psychological disorders or behavioural problems. The DRD4 gene is critical for the cognitive and emotional processes that are sub-served by neural circuits in the prefrontal cortex.

Is parent-child bed-sharing a risk for wheezing and asthma in early childhood?

Household crowding can place young children at risk for respiratory infections which subsequently provoke asthma symptoms. However, crowding might also protect against asthma, in accordance with the hygiene hypothesis. We tested if parent-infant bed-sharing, an important dimension of household crowding, increases or decreases the risk for asthma.

Are boys more sensitive to sensitivity? Parenting and executive function in preschoolers.

During early childhood, girls outperform boys on key dimensions of cognitive functions, including inhibitory control, sustained attention, and working memory. The role of parenting in these sex differences is unknown despite evidence that boys are more sensitive to the effects of the early environment. In this study, we measured parental sensitivity at 14 and 36 months of age, and children's cognitive and executive functions (sustained attention, inhibitory control, and forward/backward memory) at 52 months of age, in a longitudinal cohort (N=752).

DRD4 VNTRs, observed stranger fear in preschoolers and later ADHD symptoms.

Fear of strangers is a developmental milestone in childhood that encompasses behavioral inhibition and decreased novelty seeking. Children with attention deficit/hyperactivity disorder (ADHD) often exhibit fearless and impulsive behaviors, similar to those observed in children with atypically low levels of stranger fear. It is currently unknown whether these behaviors share common underlying biological mechanisms.

Differential susceptibility in a developmental perspective: DRD4 and maternal sensitivity predicting externalizing behavior.

This study is the first to investigate the longitudinal effects of gene-environment interplay between DRD4 genotype and maternal sensitivity on child externalizing behavior. Multiple measures of maternal sensitivity (14, 36, and 48 months) and externalizing behavior (18 months, 36 months, and 5 years) were assessed in a large cohort study (N = 548). Early maternal insensitivity (14 months) was associated with early externalizing behavior (18 months) in a for better and for worse manner, but only in children with at least one DRD4 7-repeat, consistent with a differential susceptibility model.

Ethnic differences in prevalence and determinants of mother-child bed-sharing in early childhood.

Background: To date few studies have examined how multiple layers of influences shape the emergence of bed-sharing practices in the first 2 years postpartum. In our report, we examined bed-sharing in a large multiethnic sample, exploring the influences of three broad classes of influence on bed-sharing at single time points and across time: (1) sociodemographic and (2) contextual factors such as breastfeeding, maternal mental health and stress, and (3) child temperament and sleep habits.

Methods: Frequencies of bed-sharing were assessed at two time points, 2 and 24 months, in a population-based multiethnic (Dutch, Turkish or Moroccan, and Caribbean) sample of 6309 children born in the Netherlands.

A visual aid for computer-based analysis of sleep-wake state in rats.

Computer-based sleep scoring systems are often calibrated by reference to a conventional visual analysis of electroencephalographic (EEG) and electromyographic (EMG) traces. However, these types of data place high demands on digital storage capacity which may limit the duration or feasibility of some studies. The present paper describes an approach to visual analysis that involves reconstruction of a waveform (termed a "pseudopolygram" (PPG)) from conditioned data derived from the EEG and EMG.