To sleep or to breastfeed: Associations between feeding method and sleep in infants and children.

AIM: This study aimed to understand the association between feeding method, specifically breastfeeding versus non-breastfeeding, at 6 and 12 months and infant sleep over the first 3 years of life. METHODS: A sample of 444 mother-infant dyads from the Maternal Adversity, Vulnerability and Neurodevelopment cohort were analysed. Based on retrospective maternal reports between 3-24 months, infants' breastfeeding status was determined at 6 and 12 months. Nocturnal sleep duration, longest period of consecutive sleep, and total sleep over 24 h were measured by maternal reports at 6, 12, 24 and 36 months. RESULTS: Generalized Estimating Equations revealed no significant association between feeding status, both at 6 and 12 months, and nocturnal sleep duration or total sleep over 24 h between 6-36 months (p > 0.05). However, breastfeeding at both 6 and 12 months was associated with shorter periods of consecutive sleep, at 6 and 12 months (p < 0.05) but not at 24 and 36 months (p > 0.05). CONCLUSION: Our findings suggest that breastfeeding seems to be associated with more infant sleep fragmentation but not with total sleep duration in early infancy. However, this sleep fragmentation does not persist into later infancy and early toddlerhood.

Negative emotionality as a candidate mediating mechanism linking prenatal maternal mood problems and offspring internalizing behaviour.

Negative emotionality (NE) was evaluated as a candidate mechanism linking prenatal maternal affective symptoms and offspring internalizing problems during the preschool/early school age period. The participants were 335 mother-infant dyads from the Maternal Adversity, Vulnerability and Neurodevelopment project. A Confirmatory Bifactor Analysis (CFA) based on self-report measures of prenatal depression and pregnancy-specific anxiety generated a general factor representing overlapping symptoms of prenatal maternal psychopathology and four distinct symptom factors representing pregnancy-specific anxiety, negative affect, anhedonia and somatization. NE was rated by the mother at 18 and 36 months. CFA based on measures of father, mother, child-rated measures and a semistructured interview generated a general internalizing factor representing overlapping symptoms of child internalizing psychopathology accounting for the unique contribution of each informant. Path analyses revealed significant relationships among the general maternal affective psychopathology, the pregnancy- specific anxiety, and the child internalizing factors. Child NE mediated only the relationship between pregnancy-specific anxiety and the child internalizing factors. We highlighted the conditions in which prenatal maternal affective symptoms predicts child internalizing problems emerging early in development, including consideration of different mechanistic pathways for different maternal prenatal symptom presentations and child temperament.

Maternal prenatal depression is associated with dysregulation over the first five years of life moderated by child polygenic risk for comorbid psychiatric problems.

Dysregulation is a combination of emotion, behavior, and attention problems associated with lifelong psychiatric comorbidity. There is evidence for the stability of dysregulation from childhood to adulthood, which would be more fully characterized by determining the likely stability from infancy to childhood. Early origins of dysregulation can further be validated and contextualized in association with environmental and biological factors, such as prenatal stress and polygenic risk scores (PRS) for overlapping child psychiatric problems. We aimed to determine trajectories of dysregulation from 3 months to 5 years (N = 582) in association with maternal prenatal depression moderated by multiple child PRS (N = 232 pairs with available PRS data) in a prenatal cohort. Mothers reported depression symptoms at 24-26 weeks' gestation and child dysregulation at 3, 6, 18, 36, 48, and 60 months. The PRS were for major depressive disorder, attention deficit hyperactivity disorder, cross disorder, and childhood psychiatric problems. Covariates were biological sex, maternal education, and postnatal depression. Analyses included latent classes and regression. Two dysregulation trajectories emerged: persistently low dysregulation (94%), and increasingly high dysregulation (6%). Stable dysregulation emerged at 18 months. High dysregulation was associated with maternal prenatal depression, moderated by PRS for child comorbid psychiatric problems. Males were at greater risk of high dysregulation.

Maternal symptoms of depression and sensitivity mediate the relation between maternal history of early adversity and her child temperament: The inheritance of circumstance.

We examined maternal depression and maternal sensitivity as mediators of the association between maternal childhood adversity and her child's temperament in 239 mother-child dyads from a longitudinal, birth cohort study. We used an integrated measure of maternal childhood adversity that included the Childhood Trauma Questionnaire and the Parental Bonding Index. Maternal depression was assessed with the Edinburgh Postnatal Depression Scale at 6 months postpartum. Maternal sensitivity was assessed with the Ainsworth maternal sensitivity scales at 6 months. A measure of "negative emotionality/behavioral dysregulation" was derived from the Early Childhood Behaviour Questionnaire administered at 36 months. Bootstrapping-based mediation analyses revealed that maternal depression mediated the effect of maternal childhood adversity on offspring negative emotionality/behavioral dysregulation (95% confidence interval [0.026, 0.144]). We also found a serial, indirect effect of maternal childhood adversity on child negative emotionality/behavioral mediated first by maternal depression and then by maternal sensitivity (95% confidence interval [0.031, 0.156]). Results suggest the intergenerational transmission of the effects of maternal childhood adversity to the offspring occurs through a two-step, serial pathway, involving maternal depression and maternal sensitivity.

Maternal antenatal depression and child mental health: Moderation by genomic risk for attention-deficit/hyperactivity disorder.

Maternal antenatal depression strongly influences child mental health but with considerable inter-individual variation that is, in part, linked to genotype. The challenge is to effectively capture the genotypic influence. We outline a novel approach to describe genomic susceptibility to maternal antenatal depression focusing on child emotional/behavioral difficulties. Two cohorts provided measures of maternal depression, child genetic variation, and child mental health symptoms. We constructed a conventional polygenic risk score (PRS) for attention-deficit/hyperactivity disorder (ADHD) (PRSADHD) that significantly moderated the association between maternal antenatal depression and internalizing problems at 60 months (p = 2.94 × 10-4, R2 = .18). We then constructed an interaction PRS (xPRS) based on a subset of those single nucleotide polymorphisms from the PRSADHD that most accounted for the moderation of the association between maternal antenatal depression and child outcome. The interaction between maternal antenatal depression and this xPRS accounted for a larger proportion of the variance in child emotional/behavioral problems than models based on any PRSADHD (p = 5.50 × 10-9, R2 = .27), with similar findings in the replication cohort. The xPRS was significantly enriched for genes involved in neuronal development and synaptic function. Our study illustrates a novel approach to the study of genotypic moderation on the impact of maternal antenatal depression on child mental health and highlights the utility of the xPRS approach. These findings advance our understanding of individual differences in the developmental origins of mental health.

Maternal characteristics and behavioural/emotional problems in preschoolers: how they relate to sleep rhythmic movements at sleep onset.

Sleep rhythmic movements have been speculated to be a form of self-soothing. While this sleep-related movement has been associated with lower socioeconomic status, psychopathologies and maternal characteristics, prospective studies with sizeable sample and objective measurements are lacking. The objectives were: (a) to identify maternal characteristics predicting sleep rhythmic movements in children; and (b) to document behavioural/emotional problems in preschoolers with sleep rhythmic movements. Participants were mother-child dyads (N = 529) from the Adversity: Maternal Adversity, Vulnerability and Neurodevelopment cohort. Questionnaires evaluating socioeconomic status (prenatal), maternal depressive symptoms (prenatal, 48 months), sleep rhythmic movements (12, 18, 24, 36, 48 months), maternal anxiety trait (24 months) and children's behavioural/emotional problems (48 months) were used. Maternal sensitivity (accuracy and appropriateness of mother's responses to her baby's needs) was assessed objectively with a filmed mother-infant interaction (6 months). Generalized estimating equation was used to investigate associations between sleep rhythmic movements and maternal characteristics (depression, anxiety and sensitivity). Linear regressions were used to assess associations between sleep rhythmic movements and behavioural/emotional problems in children. Lower maternal sensitivity, higher maternal depressive symptoms and lower socioeconomic status predicted sleep rhythmic movements in children (p < 0.05). To our knowledge, this is the first study showing that sleep rhythmic movements are associated with lower maternal sensitivity, measured objectively. This study also builds on previous reports, by documenting an association between sleep rhythmic movements and behavioural/emotional problems even in preschoolers. The presence of psychosocial factors in sleep rhythmic movements aetiology should be considered in treatment.

PRS-on-Spark (PRSoS): a novel, efficient and flexible approach for generating polygenic risk scores.

BACKGROUND: Polygenic risk scores (PRS) describe the genomic contribution to complex phenotypes and consistently account for a larger proportion of variance in outcome than single nucleotide polymorphisms (SNPs) alone. However, there is little consensus on the optimal data input for generating PRS, and existing approaches largely preclude the use of imputed posterior probabilities and strand-ambiguous SNPs i.e., A/T or C/G polymorphisms. Our ability to predict complex traits that arise from the additive effects of a large number of SNPs would likely benefit from a more inclusive approach. RESULTS: We developed PRS-on-Spark (PRSoS), a software implemented in Apache Spark and Python that accommodates different data inputs and strand-ambiguous SNPs to calculate PRS. We compared performance between PRSoS and an existing software (PRSice v1.25) for generating PRS for major depressive disorder using a community cohort (N = 264). We found PRSoS to perform faster than PRSice v1.25 when PRS were generated for a large number of SNPs (~ 17 million SNPs; t = 42.865, p = 5.43E-04). We also show that the use of imputed posterior probabilities and the inclusion of strand-ambiguous SNPs increase the proportion of variance explained by a PRS for major depressive disorder (from 4.3% to 4.8%). CONCLUSIONS: PRSoS provides the user with the ability to generate PRS using an inclusive and efficient approach that considers a larger number of SNPs than conventional approaches. We show that a PRS for major depressive disorder that includes strand-ambiguous SNPs, calculated using PRSoS, accounts for the largest proportion of variance in symptoms of depression in a community cohort, demonstrating the utility of this approach. The availability of this software will help users develop more informative PRS for a variety of complex phenotypes.

The early care environment and DNA methylome variation in childhood.

Prenatal adversity shapes child neurodevelopment and risk for later mental health problems. The quality of the early care environment can buffer some of the negative effects of prenatal adversity on child development. Retrospective studies, in adult samples, highlight epigenetic modifications as sentinel markers of the quality of the early care environment; however, comparable data from pediatric cohorts are lacking. Participants were drawn from the Maternal Adversity Vulnerability and Neurodevelopment (MAVAN) study, a longitudinal cohort with measures of infant attachment, infant development, and child mental health. Children provided buccal epithelial samples (mean age = 6.99, SD = 1.33 years, n = 226), which were used for analyses of genome-wide DNA methylation and genetic variation. We used a series of linear models to describe the association between infant attachment and (a) measures of child outcome and (b) DNA methylation across the genome. Paired genetic data was used to determine the genetic contribution to DNA methylation at attachment-associated sites. Infant attachment style was associated with infant cognitive development (Mental Development Index) and behavior (Behavior Rating Scale) assessed with the Bayley Scales of Infant Development at 36 months. Infant attachment style moderated the effects of prenatal adversity on Behavior Rating Scale scores at 36 months. Infant attachment was also significantly associated with a principal component that accounted for 11.9% of the variation in genome-wide DNA methylation. These effects were most apparent when comparing children with a secure versus a disorganized attachment style and most pronounced in females. The availability of paired genetic data revealed that DNA methylation at approximately half of all infant attachment-associated sites was best explained by considering both infant attachment and child genetic variation. This study provides further evidence that infant attachment can buffer some of the negative effects of early adversity on measures of infant behavior. We also highlight the interplay between infant attachment and child genotype in shaping variation in DNA methylation. Such findings provide preliminary evidence for a molecular signature of infant attachment and may help inform attachment-focused early intervention programs.

Fetal growth interacts with multilocus genetic score reflecting dopamine signaling capacity to predict spontaneous sugar intake in children.

BACKGROUND: We have shown that intrauterine growth restriction (IUGR) leads to increased preference for palatable foods at different ages in both humans and rodents. In IUGR rodents, altered striatal dopamine signaling associates with a preference for palatable foods. OBJECTIVES: Our aim was to investigate if a multilocus genetic score reflecting dopamine-signaling capacity is differently associated with spontaneous palatable food intake in children according to the fetal growth status. METHODS: 192 four-year old children from a community sample from Montreal and Hamilton, Canada, were classified according to birth weight and administered a snack test meal containing regular as well as palatable foods. Intrauterine growth restriction was based on the birth weight ratio below 0.85; children were genotyped for polymorphisms associated with dopamine (DA) signaling, with the hypofunctional variants (TaqIA-A1 allele, DRD2-141C Ins/Ins, DRD4 7-repeat, DAT1-10-repeat, Met/Met-COMT) receiving the lowest scores, and a composite score was calculated reflecting the total number of the five genotypes. Macronutrient intake during the Snack Test was the outcome. RESULTS: Adjusting for z-score BMI at 48 months and sex, there was a significant interaction of the genetic profile and fetal growth on sugar intake [߈ = -4.56, p = 0.04], showing a positive association between the genetic score and sugar intake in IUGR children, and no association in non-IUGR children. No significant interactions were seen in other macronutrients. CONCLUSIONS: Variations in a genetic score reflecting DA signaling are associated with differences in sugar intake only in IUGR children, suggesting that DA function is involved in this behavioral feature in these children. This may have important implications for obesity prevention in this population.

An Attachment-Based Model of the Relationship Between Childhood Adversity and Somatization in Children and Adults.

OBJECTIVE: An attachment model was used to understand how maternal sensitivity and adverse childhood experiences are related to somatization. METHODS: We examined maternal sensitivity at 6 and 18 months and somatization at 5 years in 292 children in a longitudinal cohort study. We next examined attachment insecurity and somatization (health anxiety, physical symptoms) in four adult cohorts: healthy primary care patients (AC1, n = 67), ulcerative colitis in remission (AC2, n = 100), hospital workers (AC3, n = 157), and paramedics (AC4, n = 188). Recall of childhood adversity was measured in AC3 and AC4. Attachment insecurity was tested as a possible mediator between childhood adversity and somatization in AC3 and AC4. RESULTS: In children, there was a significant negative relationship between maternal sensitivity at 18 months and somatization at age 5 years (B = -3.52, standard error = 1.16, t = -3.02, p = .003), whereas maternal sensitivity at 6 months had no significant relationship. In adults, there were consistent, significant relationships between attachment insecurity and somatization, with the strongest findings for attachment anxiety and health anxiety (AC1, ß = 0.51; AC2, ß = 0.43). There was a significant indirect effect of childhood adversity on physical symptoms mediated by attachment anxiety in AC3 and AC4. CONCLUSIONS: Deficits in maternal sensitivity at 18 months of age are related to the emergence of somatization by age 5 years. Adult attachment insecurity is related to somatization. Insecure attachment may partially mediate the relationship between early adversity and somatization.

A DRD4 gene by maternal sensitivity interaction predicts risk for overweight or obesity in two independent cohorts of preschool children.

BACKGROUND: Recent evidence suggests that early exposure to low maternal sensitivity is a risk factor for obesity in children and adolescents. A separate line of study shows that the seven-repeat (7R) allele of the dopamine-4 receptor gene (DRD4) increases susceptibility to environmental factors including maternal sensitivity. The current study integrates these lines of work by examining whether preschoolers carrying the 7R allele are more vulnerable to low maternal sensitivity as it relates to overweight/obesity risk. METHOD: The Maternal Adversity Vulnerability and Neurodevelopment (MAVAN) project in Canada was used as the discovery cohort (N = 203), while the Generation R study in the Netherlands was used as a replication sample (N = 270). Regression models to predict both continuous BMI z-scores and membership in any higher BMI category based on established World Health Organization (WHO) cutoffs for 48 months of age were completed. RESULTS: In both cohorts, there was a significant maternal sensitivity by DRD4 by sex interaction predicting higher body mass indices and/or obesity risk. As hypothesized, post hoc testing revealed an inverse relationship between maternal sensitivity and body mass indices in 7R allele carriers relative to noncarriers. This finding was strongest in girls in the Canadian cohort and in boys in the Dutch cohort. CONCLUSIONS: Many children who carry the 7R allele of DRD4 appear to be more influenced by maternal sensitivity as it relates to overweight/obesity risk, consistent with a plasticity effect. Given the relatively small sample sizes available for these analyses, further replications will be needed to confirm and extend these results.

Prenatal maternal depression and child serotonin transporter linked polymorphic region (5-HTTLPR) and dopamine receptor D4 (DRD4) genotype predict negative emotionality from 3 to 36 months.

Prenatal maternal depression and a multilocus genetic profile of two susceptibility genes implicated in the stress response were examined in an interaction model predicting negative emotionality in the first 3 years. In 179 mother-infant dyads from the Maternal Adversity, Vulnerability, and Neurodevelopment cohort, prenatal depression (Center for Epidemiologic Studies Depressions Scale) was assessed at 24 to 36 weeks. The multilocus genetic profile score consisted of the number of susceptibility alleles from the serotonin transporter linked polymorphic region gene (5-HTTLPR): no long-rs25531(A) (LA: short/short, short/long-rs25531(G) [LG], or LG/LG] vs. any LA) and the dopamine receptor D4 gene (six to eight repeats vs. two to five repeats). Negative emotionality was extracted from the Infant Behaviour Questionnaire-Revised at 3 and 6 months and the Early Child Behavior Questionnaire at 18 and 36 months. Mixed and confirmatory regression analyses indicated that prenatal depression and the multilocus genetic profile interacted to predict negative emotionality from 3 to 36 months. The results were characterized by a differential susceptibility model at 3 and 6 months and by a diathesis-stress model at 36 months.

Prenatal depression and 5-HTTLPR interact to predict dysregulation from 3 to 36 months--a differential susceptibility model.

BACKGROUND: Childhood dysregulation, which reflects deficits in the capacity to regulate or control one's thoughts, emotions and behaviours, is associated with psychopathology throughout childhood and into adulthood. Exposures to adversity during the prenatal period, including prenatal depression, can influence the development of dysregulation, and a number of candidate genes have been suggested as moderators of prenatal exposure, including polymorphisms in the promoter region of the serotonin transporter gene (5-HTTLPR). We examined whether prenatal depression and child 5-HTTLPR interact to predict childhood dysregulation. METHOD: Sample of N = 213 mother-child pairs from the Maternal Adversity, Vulnerability and Neurodevelopment (MAVAN) project. Mothers reported the IBQ-R at 3 and 6 months, and the ECBQ at 18 and 36 months, from which measures of dysregulation were extracted. Mothers' self-reported symptoms of depression on the CES-D at 24-36 weeks of gestation, and at 6, 12, 24 and 36 months postnatal. 5-HTTLPR genotype was extracted from buccal swabs. Mixed-model and confirmatory analyses were conducted. RESULTS: Prenatal depression and 5-HTTLPR interacted to predict dysregulation from 3 to 36 months, within a model of strong differential susceptibility. CONCLUSION: Children with S or LG alleles, when exposed to prenatal depression, have higher levels of dysregulation, and when exposed to lower or little prenatal depression, have higher capacity for regulation. Our findings support efforts to identify, support and treat prenatal depression.

The interplay of birth weight, dopamine receptor D4 gene (DRD4), and early maternal care in the prediction of disorganized attachment at 36 months of age.

Disorganized attachment is an important early risk factor for socioemotional problems throughout childhood and into adulthood. Prevailing models of the etiology of disorganized attachment emphasize the role of highly dysfunctional parenting, to the exclusion of complex models examining the interplay of child and parental factors. Decades of research have established that extreme child birth weight may have long-term effects on developmental processes. These effects are typically negative, but this is not always the case. Recent studies have also identified the dopamine D4 receptor (DRD4) as a moderator of childrearing effects on the development of disorganized attachment. However, there are inconsistent findings concerning which variant of the polymorphism (seven-repeat long-form allele or non-seven-repeat short-form allele) is most likely to interact with caregiving in predicting disorganized versus organized attachment. In this study, we examined possible two- and three-way interactions and child DRD4 polymorphisms and birth weight and maternal caregiving at age 6 months in longitudinally predicting attachment disorganization at 36 months. Our sample is from the Maternal Adversity, Vulnerability and Neurodevelopment project, a sample of 650 mother-child dyads. Birth weight was cross-referenced with normative data to calculate birth weight percentile. Infant DRD4 was obtained with buccal swabs and categorized according to the presence of the putative allele seven repeat. Macroanalytic and microanalytic measures of maternal behavior were extracted from a videotaped session of 20 min of nonfeeding interaction followed by a 10-min divided attention maternal task at 6 months. Attachment was assessed at 36 months using the Strange Situation procedure, and categorized into disorganized attachment and others. The results indicated that a main effect for DRD4 and a two-way interaction of birth weight and 6-month maternal attention (frequency of maternal looking away behavior) and sensitivity predicted disorganized attachment in robust logistic regression models adjusted for social demographic covariates. Specifically, children in the midrange of birth weight were more likely to develop a disorganized attachment when exposed to less attentive maternal care. However, the association reversed with extreme birth weight (low and high). The DRD4 seven-repeat allele was associated with less disorganized attachment (protective), while non-seven-repeat children were more likely to be classified as disorganized attachment. The implications for understanding inconsistencies in the literature about which DRD4 genotype is the risk direction are also considered. Suggestions for intervention with families with infants at different levels of biological risk and caregiving risk are also discussed.

Establishment and consolidation of the sleep-wake cycle as a function of attachment pattern.

The development of sleep-wake regulation in infants depends upon brain maturation as well as various environmental factors. The aim of the present study was to evaluate sleep duration and quality as a function of child attachment to the mother. One hundred and thirty-four mother-child dyads enrolled in the Maternal Adversity, Vulnerability and Neurodevelopment (MAVAN) project were included in this study. Attachment was assessed with the Strange Situation procedure at 36 months and maternal sleep reports were collected at 6, 12, 24 and 36 months. Differences in sleep characteristics were assessed with mixed models with one factor (attachment group) and one repeated measure (age). Children classified as disorganized had a significantly lower duration of nocturnal sleep, went to bed later, signaled more awakenings, had shorter periods of uninterrupted sleep (only at 12 months) and had shorter periods of time in bed (only at 6 months) than children classified as secure and/or ambivalent (p < 0.05). This is the first study to show that children with insecure disorganized attachment present a distinct sleep pattern in comparison with those with secure or ambivalent attachment between 6 and 36 months of age. Sleep disturbances could exacerbate difficulties in these families that are already considered vulnerable.

Low maternal sensitivity at 6 months of age predicts higher BMI in 48 month old girls but not boys.

BACKGROUND: Large population-based studies suggest that systematic measures of maternal sensitivity predict later risk for overweight and obesity. More work is needed to establish the developmental timing and potential moderators of this association. The current study examined the association between maternal sensitivity at 6 months of age and BMI z score measures at 48 months of age, and whether sex moderated this association. DESIGN: Longitudinal Canadian cohort of children from birth (the MAVAN project). METHODS: This analysis was based on a dataset of 223 children (115 boys, 108 girls) who had structured assessments of maternal sensitivity at 6 months of age and 48-month BMI data available. Mother-child interactions were videotaped and systematically scored using the Maternal Behaviour Q-Sort (MBQS)-25 items, a standardized measure of maternal sensitivity. Linear mixed-effects models and logistic regression examined whether MBQS scores at 6 months predicted BMI at 48 months, controlling for other covariates. RESULTS: After controlling for weight-relevant covariates, there was a significant sex by MBQS interaction (P=0.015) in predicting 48 month BMI z. Further analysis revealed a strong negative association between MBQS scores and BMI in girls (P=0.01) but not boys (P=0.72). Logistic regression confirmed that in girls only, low maternal sensitivity was associated with the higher BMI categories as defined by the WHO (i.e. "at risk for overweight" or above). CONCLUSIONS: A significant association between low maternal sensitivity at 6 months of age and high body mass indices was found in girls but not boys at 48 months of age. These data suggest for the first time that the link between low maternal sensitivity and early BMI z may differ between boys and girls.

Association between the seven-repeat allele of the dopamine-4 receptor gene (DRD4) and spontaneous food intake in pre-school children.

BACKGROUND: Studies in adults show associations between the hypofunctional seven-repeat allele (7R) of the dopamine-4 receptor gene (DRD4), increased eating behaviour and/or obesity, particularly in females. We examined whether 7R is associated with total caloric intake and/or food choices in pre-schoolers. METHODS: 150 four-year-old children taking part in a birth cohort study in Canada were administered a snack test meal in a laboratory setting. Mothers also filled out a food frequency questionnaire to address childrens' habitual food consumption. Total caloric and individual macronutrient intakes during the snack meal and specific types of foods as reported in the food diaries were compared across 7R allele carriers vs. non-carriers, using current BMI as a co-variate. RESULTS: We found significant sex by genotype interactions for fat and protein intake during the snack test. Post hoc testing revealed that in girls, but not boys, 7R carriers ate more fat and protein than did non-carriers. Based on the food diaries, across both sexes, 7R carriers consumed more portions of ice cream and less vegetables, eggs, nuts and whole bread, suggesting a less healthy pattern of habitual food consumption. CONCLUSION: The 7R allele of DRD4 influences macronutrient intakes and specific food choices as early as four years of age. The specific pattern of results further suggests that prior associations between the 7R allele and adult overeating/obesity may originate in food choices observable in the preschool years. Longitudinal follow-up of these children will help establish the relevance of these findings for obesity risk and prevention.

Sleep terrors in early childhood and associated emotional-behavioral problems.

STUDY OBJECTIVES: While sleep terrors are associated with emotional-behavioral problems in school-aged children and adults, little is known about these associations in early childhood, when sleep terrors prevalence is at its highest. Moreover, studies using a longitudinal design and controlling for confounding variables are scarce. This study's objective was to determine whether the frequency of sleep terrors in toddlers predicts emotional-behavioral problems during the preschool years. METHODS: Participants (n = 324) were enrolled in the prospective Maternal Adversity Vulnerability and Neurodevelopment cohort study. The frequency of sleep terrors in children was assessed at 12, 18, 24, and 36 months using maternal reports. Children's emotional-behavioral problems were measured at 48 and 60 months using the Child Behavior Checklist. Relevant confounders linked to the child, mother, and environment were also taken into consideration. RESULTS: The frequency of sleep terrors was relatively stable across early childhood (16.7-20.5%). A generalized estimating equation revealed that the frequency of sleep terrors in early childhood was associated with increased emotional-behavioral problems at 4 and 5 years of age, more specifically with internalizing problems (P < .001), after controlling for child's sex, time point, family socioeconomic status, maternal depressive symptoms, and nighttime sleep duration. The frequency of sleep terrors was further associated with the emotionally reactive, anxious/depressed, and somatic complaints scales (P < .01). CONCLUSIONS: This longitudinal study provides further support for a high prevalence of sleep terrors in early childhood. Our findings show meaningful associations between higher frequency of sleep terrors and emotional-behavioral problems as early as toddlerhood, especially internalizing problems. CITATION: Laganière C, Gaudreau H, Pokhvisneva I, et al. Sleep terrors in early childhood and associated emotional-behavioral problems. J Clin Sleep Med. 2022;18(9):2253-2260.

Bacteriocins as a new generation of antimicrobials: toxicity aspects and regulations.

In recent decades, bacteriocins have received substantial attention as antimicrobial compounds. Although bacteriocins have been predominantly exploited as food preservatives, they are now receiving increased attention as potential clinical antimicrobials and as possible immune-modulating agents. Infections caused by antibiotic-resistant bacteria have been declared as a global threat to public health. Bacteriocins represent a potential solution to this worldwide threat due to their broad- or narrow-spectrum activity against antibiotic-resistant bacteria. Notably, despite their role in food safety as natural alternatives to chemical preservatives, nisin remains the only bacteriocin legally approved by regulatory agencies as a food preservative. Moreover, insufficient data on the safety and toxicity of bacteriocins represent a barrier against the more widespread use of bacteriocins by the food and medical industry. Here, we focus on the most recent trends relating to the application of bacteriocins, their toxicity and impacts.