Attachment security and disorganization in infants of mothers with severe psychiatric disorder: Exploring the role of comorbid personality disorder.

The aim of this preliminary study was to explore infant-mother attachment quality in a Dutch clinical sample of mothers with severe psychiatric disorder, with or without comorbid personality disorder. Thirty-two mothers were recruited through specialized secondary and tertiary outpatient clinics and mental health institutions. Maternal psychiatric and personality diagnoses were verified with structured clinical interviews during pregnancy. Maternal concurrent level of psychiatric symptoms was assessed by self-report and infant-mother attachment quality by observation in the Strange Situation Procedure at 14 months postpartum. In the full sample, almost half of the infants were classified as disorganized. All infants of mothers with a comorbid personality disorder were classified as either insecure or disorganized. Infants of mothers with a comorbid personality disorder had a significantly higher disorganization score than infants of mothers with a psychiatric disorder only. Continuous attachment security scores did not differ significantly between groups. In the full sample, continuous infant attachment security and disorganization score were not significantly correlated with the level of maternal concurrent psychiatric symptoms. Our exploratory findings suggest a specific link between maternal psychiatric and comorbid personality disorder and attachment disorganization. Moreover, chronicity of symptoms appears more relevant for attachment behaviors than the severity of concurrent psychiatric symptoms. Maternal personality disorder may have a strong formative impact on infant attachment security and disorganization, which warrants further research to inform clinical practice, in order to reduce the risk of intergenerational transmission of maternal psychopathology.

Harry Harlow's pit of despair: Depression in monkeys and men.

Major depressive disorder is the most common mood disorder in the United States today and the need for adequate treatment has been universally desired for over a century. Harry Harlow, famous for his research with rhesus monkeys, was heavily criticized when he undertook his controversial experiments trying to find a solution for depression in the 1960s-1970s. His research, however, did not just evolve gradually from his earlier research into learning and into love. Recently disclosed hand-written notes show, for the first time, the severity of Harlow's depressions as he wrote in detail about his feelings and thoughts during his stay in a mental hospital in 1968. In these notes, Harlow repeatedly vowed to put every effort into finding a cure for depression. This may, for a large part, explain why he did not stop his rigorous animal experiments where critics argue he should have, and he eventually managed to book positive results.

Children's autistic traits and peer relationships: do non-verbal IQ and externalizing problems play a role?

BACKGROUND: Children with autism have difficulties in understanding relationships, yet little is known about the levels of autistic traits with regard to peer relationships. This study examined the association between autistic traits and peer relationships. Additionally, we examined whether the expected negative association is more pronounced in children with a lower non-verbal IQ and in those who exhibit more externalizing problems. METHOD: Data were collected in a large prospective birth cohort of the Generation R Study (Rotterdam, the Netherlands) for which nearly 10,000 pregnant mothers were recruited between 2002 and 2006. Follow up data collection is still currently ongoing. Information on peer relationships was collected with PEERS application, an interactive computerized task (M = 7.8 years). Autistic traits were assessed among general primary school children by using the Social Responsiveness Scale (M = 6.1 years). Information was available for 1580 children. RESULT: Higher levels of autistic traits predicted lower peer acceptance and higher peer rejection. The interaction of autistic traits with externalizing problems (but not with non-verbal IQ or sex) was significant: only among children with low externalizing problems, a higher level of autistic traits predicted less peer acceptance and more peer rejection. Among children exhibiting high externalizing problems, a poor peer acceptance and high level of rejection is seen independently of the level of autistic traits. CONCLUSION: We conclude that autistic traits-including traits that do not classify as severe enough for a clinical diagnosis-as well as externalizing problems negatively impact young children's peer relationships. This suggests that children with these traits may benefit from careful monitoring and interventions focused at improving peer relationships.

Aggressive behavior, emotional, and attention problems across childhood and academic attainment at the end of primary school.

PURPOSE: To assess whether aggressive behavior and emotional problems from early childhood onwards are related to academic attainment at the end of primary education, and whether these associations are independent of attention problems. METHODS: Data on 2546 children participating in a longitudinal birth cohort in Rotterdam were analyzed. Aggressive behavior, attention and emotional problems at ages 1½, 3, 5 and 10 years were assessed with the Child Behavior Checklist. Academic attainment at the end of primary school (12 years of age) was measured with the CITO test, a national Dutch academic test score. RESULTS: Aggressive behavior from age 1½ to 10 years was negatively associated with academic attainment, but these associations attenuated to non-significance when accounting for comorbid attention problems. For emotional problems, first, only problems at 10 years were associated with poorer academic attainment. Yet, when accounting for attention problems, the association reversed: more emotional problems from 1½ to 10 years were associated with a better academic attainment. Attention problems at ages 1½ to 10 years were negatively associated with academic attainment, independent of comorbid emotional problems or aggressive behavior. CONCLUSIONS: Attention problems across childhood are related to a poorer academic attainment, while emotional problems predicted better academic attainment. Moreover, the relationship between aggressive behavior and academic attainment was explained by comorbid attention problems. Future research should determine the mechanisms through which attention problems and emotional problems affect academic attainment, to inform strategies for the promotion of better educational attainment.

Psychotic experiences and future school performance in childhood: a population-based cohort study.

BACKGROUND: Psychotic experiences are common in childhood and an important risk indicator of adverse mental health outcomes. However, little is known about the association of psychotic experiences with functional outcomes in childhood, particularly regarding school performance. The aim of the present study was to examine whether psychotic experiences were prospectively related to school performance in childhood. METHODS: This study was embedded in the population-based Generation R Study (N = 2,362). Psychotic experiences were assessed using self-reports on hallucinations at age 10 years. School performance was assessed using a standardized national school performance test at age 12 years. We considered the total school performance score, as well as language and mathematics subscales. Analyses were adjusted for sociodemographic characteristics, maternal nonverbal IQ, nonverbal IQ at age 6 years and co-occurring psychopathology at age 10 years. RESULTS: Psychotic experiences were prospectively associated with poorer school performance scores (B = -0.61, 95% CI [-0.98;-0.25], p = .001), as well as poorer language (Bpercentile rank score  = -2.00, 95% CI [-3.20;-0.79], p = .001) and mathematical ability (Bpercentile rank score  = -1.75, 95% CI [-2.99;-0.51], p = .006). These associations remained after additional adjustment for nonverbal IQ at age 6 years (B = -0.51, 95% CI [-0.86;-0.16], p = .005), and co-occurring internalizing (B = -0.40, 95% CI [-0.77;-0.03], p = .036) and externalizing problems (B = -0.40, 95% CI [-0.75;-0.04], p = .029), but not attention problems (B = -0.10, 95% CI [-0.47;0.26], p = .57). CONCLUSIONS: Children with psychotic experiences had lower school performance scores than their nonaffected peers. The finding was independent of sociodemographic characteristics, intelligence and co-occurring internalizing and externalizing problems, but not attention problems. This study suggests that psychotic experiences are associated with childhood functional impairments, although the relatively small effects and the role of attention problems warrant further exploration.

Sleep characteristics across the lifespan in 1.1 million people from the Netherlands, United Kingdom and United States: a systematic review and meta-analysis.

We aimed to obtain reliable reference charts for sleep duration, estimate the prevalence of sleep complaints across the lifespan and identify risk indicators of poor sleep. Studies were identified through systematic literature search in Embase, Medline and Web of Science (9 August 2019) and through personal contacts. Eligible studies had to be published between 2000 and 2017 with data on sleep assessed with questionnaires including ≥100 participants from the general population. We assembled individual participant data from 200,358 people (aged 1-100 years, 55% female) from 36 studies from the Netherlands, 471,759 people (40-69 years, 55.5% female) from the United Kingdom and 409,617 people (≥18 years, 55.8% female) from the United States. One in four people slept less than age-specific recommendations, but only 5.8% slept outside of the 'acceptable' sleep duration. Among teenagers, 51.5% reported total sleep times (TST) of less than the recommended 8-10 h and 18% report daytime sleepiness. In adults (≥18 years), poor sleep quality (13.3%) and insomnia symptoms (9.6-19.4%) were more prevalent than short sleep duration (6.5% with TST < 6 h). Insomnia symptoms were most frequent in people spending ≥9 h in bed, whereas poor sleep quality was more frequent in those spending <6 h in bed. TST was similar across countries, but insomnia symptoms were 1.5-2.9 times higher in the United States. Women (≥41 years) reported sleeping shorter times or slightly less efficiently than men, whereas with actigraphy they were estimated to sleep longer and more efficiently than man. This study provides age- and sex-specific population reference charts for sleep duration and efficiency which can help guide personalized advice on sleep length and preventive practices.

The interparental relationship: Meta-analytic associations with children's maladjustment and responses to interparental conflict.

The aim of the current meta-analysis was to aggregate concurrent and longitudinal empirical research on associations between the interparental relationship and both children's maladjustment (i.e., externalizing and internalizing symptoms) and children's responses to interparental conflict (i.e., emotional, behavioral, cognitive, and physiological). Based on major theoretical frameworks, we distinguished between six dimensions of the interparental relationship: relationship quality, conflict frequency, hostile, disengaged, and unconstructive forms of conflict, and child-related conflict. A final selection of 169 studies for child maladjustment and 61 studies for child responses to conflict were included. The findings revealed by the expansive and fine-grained approach of this meta-analysis support and challenge theoretical hypotheses about the relative predictive value of dimensions of the interparental relationship for children's functioning. Although hostility was specifically more strongly associated with children's externalizing behavior and emotional responses to conflict, disengaged and unconstructive conflict behavior posed similar risks for the other domains of child functioning. In addition, relationship quality, conflict frequency, and child-related conflict warrant more attention in theoretical frameworks, as these dimensions posed similar risks to child functioning as the different forms of conflict. Moreover, most associations between the interparental relationship and child functioning endured over time. Also, developmental and gender differences appeared to depend on the specific forms of interparental conflict and the domain of child functioning. In sum, the results support the growing consensus that prevention and intervention programs aimed at children's mental health could benefit from an alternative or additional focus on the interparental relationship. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

[Sleep problems in young children; a plea to broaden the spectrum of interventions]. / Slaapproblemen bij jonge kinderen.

One in ten parents in the Netherlands feels there is a problem with their baby's sleep. Healthy sleep is very important for children and parents. Because of the many questions asked by parents, professionals are in need of clear guidelines. The guideline 'Healthy sleep and sleep problems in children', provided by the Dutch centre for youth health (NCJ, Nederlands Centrum Jeugdgezondheid) provides information on promoting healthy sleep behaviour and sleep interventions. We argue in this article that: (a) parents may have doubts about the recommended interventions; (b) the interventions are often not compatible with the concept of 'sensitive parenting'; and (c) the guideline does not include all possible interventions. We are pleading for a broadening of the spectrum of interventions. It is in the interest of parents as well as infants that interventions aimed at the needs of the infant are included in the spectrum of sleep interventions being offered.

The Complex Role of Parental Separation in the Association between Family Conflict and Child Problem Behavior.

Parental separation is a major adverse childhood experience. Parental separation is generally preceded by conflict, which is itself a risk factor for child problem behavior. Whether parental separation independent of conflict has negative effects on child problem behavior is unclear. This study was embedded in Generation R, a population-based cohort followed from fetal life until age 9 years. Information on family conflict was obtained from 5,808 mothers and fathers. The 4-way decomposition method was used to apportion the effects of prenatal family conflict and parental separation on child problem behavior into 4 nonoverlapping components. Structural equation modeling was used to test bidirectional effects of child problem behavior and family conflict over time. Family conflict from pregnancy onward and parental separation each strongly predicted child problem behavior up to preadolescence according to maternal and paternal ratings. Using the 4-way decomposition method, we found evidence for a strong direct effect of prenatal family conflict on child problem behavior, for reference interaction, and for mediated interaction. The evidence for interaction implies that prenatal family conflict increased the children's vulnerability to the harmful effect of parental separation. There was no evidence of a pure indirect effect of parental separation on child problem behavior. Overall, results indicated that if parental separation occurs in families with low levels of conflict, parental separation does not predict more child problem behavior. Moreover, the bidirectional pattern suggested that child problem behavior influences the persistence of family conflict.

Association of Slight to Mild Hearing Loss With Behavioral Problems and School Performance in Children.

Importance: Children with severe hearing loss are known to have more behavioral problems and may perform worse at school than children without. Few large-scale studies of slight to mild hearing loss are available. Objective: To examine the relevance of slight to mild hearing loss by studying its association with behavioral problems and school performance. Design, Setting, and Participants: This cross-sectional study was performed within an ongoing prospective birth cohort study in Rotterdam, the Netherlands. Participants were part of a population-based sample of children. Between ages 9 and 11 years, 5355 children underwent audiometric and behavioral evaluations. Children were excluded if they had missing data for either audiometry or both outcomes. Data were collected from April 2012 through October 2015. Data were analyzed from March to June 2018. Exposures: Audiometric evaluation included pure-tone audiometry tests and speech-in-noise testing. Main Outcomes and Measures: Child behavior was rated by the primary caregiver using the Child Behavior Checklist at ages 9 to 11 years (n = 4471). School performance was measured with a standardized test at age 12 years (n = 2399). Results: The final sample included 4779 participants who were a mean (SD) age of 9.8 (0.3) years. The sample had nearly equal distribution between boys (n = 2200; 49.2%) and girls (n = 2271; 50.8%). Associations of hearing thresholds with behavioral problems differed between boys and girls. Among boys, higher pure-tone hearing thresholds at low frequencies were associated with higher total problem, social problem, and attention problem scores (total problems for the better-hearing ear: ß = 0.01; 95% CI, 0-0.02). Higher speech reception thresholds were associated with higher attention problem scores among girls (ß = 0.04; 95% CI, 0-0.08). Higher speech reception thresholds were associated with poorer school performance scores for both boys and girls (ß = -0.06; 95% CI, -0.10 to -0.02). Conclusions and Relevance: Higher hearing thresholds during pure-tone audiometric and speech-in-noise testing were associated with higher behavioral problem scores and poorer school performance. This supports the relevance of slight to mild hearing loss with these outcomes in school-aged children.

Observed infant-parent attachment and brain morphology in middle childhood- A population-based study.

Poor quality of the early infant-parent bond predicts later child problems. Infant-parent attachment has been suggested to influence brain development, but this association has hardly been examined. In adults, larger amygdala volumes have been described in relation to early attachment disorganization; neuroimaging studies of attachment in children, however, are lacking. We examined the association between infant-parent attachment and brain morphology in 551 children from a population-based cohort in the Netherlands. Infant-parent attachment was observed with the Strange-Situation Procedure at age 14 months and different brain measures were collected with magnetic resonance imaging at mean age 10 years. Children with disorganized infant attachment had larger hippocampal volumes than those with organized attachment patterns. This finding was robust to the adjustment for confounders and consistent across hemispheres. The association was not explained by cognitive or emotional and behavioral problems. Disorganized attachment did not predict any other difference in brain morphology. Moreover, children with insecure organized infant attachment patterns did not differ from those who were securely attached in any brain outcome. Causality cannot be inferred, but our findings in this large population-based study provide novel evidence for a long-term association between the quality of infant-parent attachment and specific brain differences in childhood.

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. Family irregularity was measured with seven maternal-reported questions on family routines when children were 2 and 4 years old. Mothers reported on sleep problems at child age 3, 6, and 10 years, whereas children completed questionnaires on sleep problems at age 10. Additionally, we used tri-axial wrist accelerometers for five nights in 851 children (mean age 11.7 years) to assess sleep objectively. RESULTS: Family irregularity was associated with more mother- and child-reported sleep problems at ages 3, 6, and 10 years as well as with a shorter sleep duration and later objective sleep onset, but not with sleep efficiency or waking time. The association between family irregularity and multi-informant subjective sleep problems at age 10 years was mediated by mother-reported child psychopathology at age 6 years. CONCLUSIONS: Our findings show a long-term robust association of preschool family irregularity with more sleep problems during childhood as well as shorter sleep duration and later sleep onset as measured objectively with actigraphy. In part, these sleep problems were associated with family irregularity by way of child psychopathology. These findings suggest that interventions improving preschool family irregularity, which are targeted to reduce child psychopathology, may also impact the development of sleep problems beneficially.

Gestational age at birth and sleep duration in early childhood in three population-based cohorts.

BACKGROUND: Both preterm and post-term births have been associated with neonatal morbidity and mortality, including adverse impact on neurodevelopment. Important neural maturational processes take place during sleep in newborns, but findings on gestational duration and sleep in early childhood are contradictory and often derive from small clinical samples. We studied the association of gestational age at birth with sleep duration in early childhood in three population-based cohorts. METHODS: Gestational age at birth and sleep duration were assessed in three population-based cohort studies in The Netherlands (n = 6471), Singapore (n = 862), and Canada (n = 583). Gestational age at birth was assessed using ultrasound in pregnancy in combination with date of birth, and caregivers repeatedly reported on child sleep duration at three, six, 24, and 36 months of age. Generalized estimating equations were used, which were adjusted for confounders, and findings were pooled in a meta-analysis. RESULTS: Children born preterm (<37 weeks of gestation) showed longer sleep duration than children born at term; and children born post-term (≥42 weeks of gestation) showed shorter sleep duration. The meta-analysis indicated a small negative effect of gestational age on child sleep duration (effect size -0.11), when assessed in children born at term only. CONCLUSION: In early childhood, children with a lower gestational age have a longer sleep duration, even when they are born at term (37-42 weeks of gestation). These subtle yet consistent findings point to the importance of maturational processes during sleep, not only in premature children but also in children born at term after shorter gestational duration.

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. They have been associated with sleep problems, but studies with objective sleep measures are lacking. This study assessed whether psychotic experiences were associated with actigraphic sleep measures, symptoms of dyssomnia, nightmares, or other parasomnias. METHODS: This cross-sectional population-based study comprises 4149 children from the Generation R Study. At age 10 years, psychotic experiences including hallucinatory phenomena were assessed by self-report; dyssomnia and parasomnia symptoms were assessed by mother- and child-report. Additionally, at age 11 years, objective sleep parameters were measured using a tri-axial wrist accelerometer in N = 814 children, who wore the accelerometer for five consecutive school days. RESULTS: Psychotic experiences were not associated with objective sleep duration, sleep efficiency, arousal, or social jetlag. However, psychotic experiences were associated with self-reported dyssomnia (B = 2.45, 95%CI: 2.13-2.77, p < 0.001) and mother-reported parasomnia, specifically nightmares (ORadjusted = 3.59, 95%CI 2.66-4.83, p < 0.001). Similar results were found when analyses were restricted to hallucinatory phenomena. CONCLUSIONS: Childhood psychotic experiences were not associated with objective sleep measures. In contrast, psychotic experiences were associated with nightmares, which are a known risk indicator of psychopathology in pre-adolescence. More research is needed to shed light on the potential etiologic or diagnostic role of nightmares in the development of psychotic phenomena.

The bidirectional association between sleep problems and autism spectrum disorder: a population-based cohort study.

Background: Sleep difficulties are prevalent in children with autism spectrum disorder (ASD). The temporal nature of the association between sleep problems and ASD is unclear because longitudinal studies are lacking. Our aim is to clarify whether sleep problems precede and worsen autistic traits and ASD or occur as a consequence of the disorder. Methods: Repeated sleep measures were available at 1.5, 3, 6, and 9 years of age in 5151 children participating in the Generation R Study, a large prospective birth cohort in the Netherlands. Autistic traits were determined with the Pervasive Developmental Problems score (PDP) of the Child Behavior Checklist (CBCL) at 1.5 and 3 years and the Social Responsiveness Scale (SRS) at 6 years. This cohort included 81 children diagnosed with ASD. Results: Sleep problems in early childhood were prospectively associated with a higher SRS score, but not when correcting for baseline PDP score. By contrast, a higher SRS score and an ASD diagnosis were associated with more sleep problems at later ages, even when adjusting for baseline sleep problems. Likewise, a trajectory of increasing sleep problems was associated with ASD. Conclusions: Sleep problems and ASD are not bidirectionally associated. Sleep problems do not precede and worsen autistic behavior but rather co-occur with autistic traits in early childhood. Over time, children with ASD have an increase in sleep problems, whereas typically developing children have a decrease in sleep problems. Our findings suggest that sleep problems are part of the construct ASD.

The Prospective Association of the Diurnal Cortisol Rhythm With Sleep Duration and Perceived Sleeping Problems in Preschoolers: The Generation R Study.

OBJECTIVE: Cortisol, the end product of the hypothalamic-pituitary-adrenal axis, plays an important role in modulating sleep. Yet, studies investigating the association between diurnal cortisol rhythm and sleep patterns in young children are scarce. We tested the hypothesis that the diurnal cortisol rhythm is associated with shorter sleep duration and more sleep problems across early childhood. METHODS: This study was embedded in Generation R, a population-based cohort from fetal life onward. Parents collected saliva samples from their infant at five moments during day 1. In 322 infants aged 12 to 20 months, we determined the diurnal cortisol rhythm by calculating the area under the curve (AUC), the cortisol awakening response (CAR), and the diurnal slope. Sleep duration and sleep behavior were repeatedly assessed across ages of 14 months to 5 years. Generalized estimating equation models were used to assess related cortisol measures to sleep duration and sleep behavior. RESULTS: The diurnal cortisol slope and the CAR, but not the AUC, were associated with sleep duration across childhood. Children with flatter slopes and children with a more positive CAR were more likely to have shorter nighttime sleep duration (ß per nmol/L/h slope = -0.12, 95% confidence interval = -0.19 to -0.05, p = .001; ß per nmol/L CAR = -0.01, 95% confidence interval = -0.02 to 0.00, p = .04). Cortisol measures did not predict sleep problems. CONCLUSIONS: The present study suggests that a flatter diurnal cortisol slope and a more marked morning rise, which can indicate stress (or hypothalamic-pituitary-adrenal dysregulation), have a long-term association with sleep regulation.

The Developmental Course of Sleep Disturbances Across Childhood Relates to Brain Morphology at Age 7: The Generation R Study.

Objectives: Little is known about the impact of sleep disturbances on the structural properties of the developing brain. This study explored associations between childhood sleep disturbances and brain morphology at 7 years. Methods: Mothers from the Generation R cohort reported sleep disturbances in 720 children at ages 2 months, 1.5, 2, 3, and 6 years. T1-weighted Magnetic Resonance Imaging (MRI) images were used to assess brain structure at 7 years. Associations of sleep disturbances at each age and of sleep disturbance trajectories with brain volumes (total brain volume, cortical and subcortical grey matter, white matter) were tested with linear regressions. To assess regional differences, sleep disturbance trajectories were tested as determinants for cortical thickness in whole-brain analyses. Results: Sleep disturbances followed a declining trend from toddlerhood onwards. Infant sleep was not associated with brain morphology at age 7. Per SD sleep disturbances (one frequent symptom or two less frequent symptoms) at 2 and 3 years of age, children had -6.3 (-11.7 to -0.8) cm3 and -6.4 (-11.7 to -1.7) cm3 smaller grey matter volumes, respectively. Sleep disturbances at age 6 years were associated with global brain morphology (grey matter: -7.3 (-12.1 to -2.6), p value = .01). Consistently, trajectory analyses showed that more adverse developmental course of childhood sleep disturbances are associated with smaller grey matter volumes and thinner dorsolateral prefrontal cortex. Conclusion: Sleep disturbances from age 2 years onwards are associated with smaller grey matter volumes. Thinner prefrontal cortex in children with adverse sleep disturbance trajectories may reflect effects of sleep disturbances on brain maturation.

Methylation matters: FK506 binding protein 51 (FKBP5) methylation moderates the associations of FKBP5 genotype and resistant attachment with stress regulation.

The parent-child attachment relationship plays an important role in the development of the infant's stress regulation system. However, genetic and epigenetic factors such as FK506 binding protein 51 (FKBP5) genotype and DNA methylation have also been associated with hypothalamus-pituitary-adrenal axis functioning. In the current study, we examined how parent-child dyadic regulation works in concert with genetic and epigenetic aspects of stress regulation. We study the associations of attachment, extreme maternal insensitivity, FKBP5 single nucleotide polymorphism 1360780, and FKBP5 methylation, with cortisol reactivity to the Strange Situation Procedure in 298 14-month-old infants. The results indicate that FKBP5 methylation moderates the associations of FKBP5 genotype and resistant attachment with cortisol reactivity. We conclude that the inclusion of epigenetics in the field of developmental psychopathology may lead to a more precise picture of the interplay between genetic makeup and parenting in shaping stress reactivity.

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. Our review offers a narrative walkthrough of the many subdomains of bed-sharing research, including its many correlates (e.g., socioeconomic and cultural factors) and purported risks or outcomes (e.g., sudden infant death syndrome, sleep problems). We found general design limitations and a lack of convincing evidence in the literature, which preclude making strong generalizations. A heat-map based on 98 eligible studies aids the reader to visualize world-wide prevalence in bed-sharing and highlights the need for further research in societies where bed-sharing is the norm. We urge for multiple subfields - anthropology, psychology/psychiatry, and pediatrics - to come together with the aim of understanding infant sleep and how nightly proximity to the parents influences children's social, emotional, and physical development.