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The current study aims to clarify the temporal associations between maternal sensitivity and children's sleep problems across early childhood. This study comprised 942 Dutch mother-child dyads from the Generation R Study, a population-based prospective cohort study. Throughout early childhood, maternal sensitivity was observed in mother-child interactions and coded using Ainsworth's 9-point rating scales (1.5 years) and the revised Erickson 7-point rating scales (3 and 4 years). Caregivers reported children's sleep problems on the Sleep Problems Scale of the Child Behaviour Checklist 1½-5 at child ages 1.5, 3, and 6 years. Cross-lagged panel modelling revealed that higher levels of maternal sensitivity (3 years) were associated with fewer sleep problems (6 years); all other temporal associations between maternal sensitivity and children's sleep problems were nonsignificant. In conclusion, some indication of an association of parenting with children's sleep across early childhood was found, but there was no evidence for bidirectional associations over time.

ABSTRACT Child safety is an important outcome of child protection services (CPSs); however, this is often assessed in terms of official registries (e.g., rereports). Little empirical evidence is available about how the frequency of child maltreatment changes during CPS intervention by using self‐report measures. The present study evaluates the frequency of child maltreatment experienced by children receiving mandatory child protection support compared to carefully matched children receiving voluntary child protection support. The current study is part of an ongoing Dutch longitudinal study on family violence consisting of several cohorts with similar designs. Both parents and children reported on the frequency of child maltreatment using validated questionnaires at two timepoints, 12 months apart. To facilitate careful comparison, both groups were matched using propensity scores based on background variables, resulting in two groups of N = 178 children. GLMM analyses showed a significant decrease in the mean number of child maltreatment incidents over time in the total group. However, this decrease did not differ for children receiving mandatory and voluntary child protection support. The findings indicate that, despite possible motivational challenges in the mandatory group, mandatory child protection support elicits comparable results as voluntary support. Implications for further research and practice are discussed. [ABSTRACT FROM AUTHOR]

The current study aims to clarify the temporal associations between maternal sensitivity and children's sleep problems across early childhood. This study comprised 942 Dutch mother–child dyads from the Generation R Study, a population-based prospective cohort study. Throughout early childhood, maternal sensitivity was observed in mother–child interactions and coded using Ainsworth's 9-point rating scales (1.5 years) and the revised Erickson 7-point rating scales (3 and 4 years). Caregivers reported children's sleep problems on the Sleep Problems Scale of the Child Behaviour Checklist 1½−5 at child ages 1.5, 3, and 6 years. Cross-lagged panel modelling revealed that higher levels of maternal sensitivity (3 years) were associated with fewer sleep problems (6 years); all other temporal associations between maternal sensitivity and children's sleep problems were nonsignificant. In conclusion, some indication of an association of parenting with children's sleep across early childhood was found, but there was no evidence for bidirectional associations over time. [ABSTRACT FROM AUTHOR]

Background and methods: In two birth cohort studies with genetic, sensitive parenting, and attachment data of more than 1,000 infants in total, we tested main and interaction effects of candidate genes involved in the dopamine, serotonin, and oxytocin systems ("DRD4", "DRD2", "COMT", "5-HTT", "OXTR") on attachment security and disorganization. Parenting was assessed using observational rating scales for parental sensitivity (Ainsworth, Bell, & Stayton, 1974), and infant attachment was assessed with the Strange Situation Procedure. Results: We found no consistent additive genetic associations for attachment security and attachment disorganization. However, specific tests revealed evidence for a codominant risk model for "COMT" Val158Met, consistent across both samples. Children with the Val/Met genotype showed higher disorganization scores (combined effect size d = 0.22, CI = 0.10-0.34, p less than 0.001). Gene-by-environment interaction effects were not replicable across the two samples. Conclusions: This unexpected finding might be explained by a broader range of plasticity in heterozygotes, which may increase susceptibility to environmental influences or to dysregulation of emotional arousal. This study is unique in combining the two largest attachment cohorts with molecular genetic and observed rearing environment data to date.

In this meta-analysis of 75 studies on more than 3,888 children in 19 different countries, the intellectual development of children living in children's homes (orphanages) was compared with that of children living with their (foster) families. Children growing up in children's homes showed lower IQ's than did children growing up in a family (trimmed d = 0.74). The age at placement in the children's home, the age of the child at the time of assessment, and the developmental level of the country of residence were associated with the size of the delays. Children growing up in children's homes show a substantial lower level of IQ (average IQ of 84) than their peers reared in (foster) families (average IQ of 104), and the difference amounted to 20 IQ points. More research is needed to detect the causes of the large IQ delays and to test ways of improving the intellectual development of millions of children in orphanages around the world. (Contains 3 tables.)

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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM PUBLISHER]

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., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

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.

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: β = 0.01; 95% CI, 0-0.02). Higher speech reception thresholds were associated with higher attention problem scores among girls (β = 0.04; 95% CI, 0-0.08). Higher speech reception thresholds were associated with poorer school performance scores for both boys and girls (β = -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.

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.

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., (Copyright © 2019 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

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., (© 2019 The Authors. Journal of Child Psychology and Psychiatry published by John Wiley & Sons Ltd on behalf of Association for Child and Adolescent Mental Health.)

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., Competing Interests: All authors have no conflict of interest to declare. There was no external grant or financial support for this study. The ICMJE Uniform Disclosure Form for Potential Conflicts of Interest associated with this article can be viewed by clicking on the following link: https://doi.org/10.1016/j.sleepx.2019.100002., (© 2019 The Authors.)

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 (OR adjusted  = 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., (Copyright © 2018 Elsevier B.V. All rights reserved.)

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.

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., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

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.D.S. Ainsworth, M.C. Blehar, E. Waters, & S. Wall, 1978) at 14 months. When using a dichotomous variable, "never bed-sharing" (solitary sleepers) versus "any bed-sharing," the relative risk of being classified as insecurely attached for solitary-sleeping infants (vs. bed-sharers) was 1.21 (95% confidence interval: 1.05-1.40). In multivariate models, solitary sleeping was associated with greater odds of insecure attachment, adjusted odds ratio (OR): 1.50, 95% CI = 1.02-2.20) and, in particular, with greater odds of resistant attachment, adjusted OR = 1.74, 95% CI = 1.10-2.76); and with a lower attachment security score, β = -0.12, t(495) = -2.61, p = .009. However, we found no evidence of a dose-response association between bed-sharing and secure attachment when using a trichotomous bed-sharing variable based on frequency of bed-sharing. Our findings demonstrate some evidence that solitary sleeping is associated with insecure attachment. However, the lack of a dose-response association suggests that further experimental study is necessary before accepting common notions that sharing a bed leads to children who are better or not better adjusted., (© 2015 Michigan Association for Infant Mental Health.)

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. In a population-based prospective cohort (N = 6160) we assessed bed-sharing at 2 and 24 months; wheezing between 1 and 6 years of age; and asthma at 6 years of age. Generalised estimating equation models were used to assess repeated measures of wheezing and asthma. We found no association between bed-sharing in early infancy and wheezing or diagnosis of asthma. By contrast, we found a positive association between bed-sharing in toddlerhood and both wheezing (OR 1.42, 95% CI 1.15-1.74) and asthma (OR 1.57, 95% CI 1.03-2.38). Wheezing was not associated with bed-sharing when using cross-lagged modelling. This study suggests that bed-sharing in toddlerhood is associated with an increased risk of asthma at later ages, and not vice versa. Further studies are needed to explore the underlying causal mechanisms., (Copyright ©ERS 2015.)

Although the environmental influences on infant attachment disorganization and security are well-studied, little is known about their heritability. Candidate gene studies have shown small, often non-replicable effects. In this study, we gathered the largest sample (N = 657) of ethnically homogenous, 14-month-old children with both observed attachment and genome-wide data. First, we used a Genome-Wide Association Study (GWAS) approach to identify single nucleotide polymorphisms (SNPs) associated with attachment disorganization and security. Second, we annotated them into genes (Versatile Gene-based Association Study) and functional pathways. Our analyses provide evidence of novel genes (HDAC1, ZNF675, BSCD1) and pathways (synaptic transmission, cation transport) associated with attachment disorganization. Similar analyses identified a novel gene (BECN1) but no distinct pathways associated with attachment security. The results of this first extensive, exploratory study on the molecular-genetic basis of infant attachment await replication in large, independent samples.

We examined associations of disorganized attachment and maternal depressive symptoms with infant autonomic functioning in 450 infant-mother dyads enrolled in the Generation R study. Maternal depressive symptoms were measured 2 months postpartum with the Brief Symptom Inventory. At 14 months, we assessed infant attachment with a slightly shortened Strange Situation and measured infant resting heart rate. Respiratory sinus arrhythmia (RSA) was calculated using spectral analysis. Higher levels of maternal postnatal depressive symptoms predicted lower resting RSA in disorganized infants (B = -0.31, SE = 0.15, p = .04, R(2)  = .05) but not in nondisorganized infants (B = 0.05, SE = 0.06, p = .36). This effect was buffered in disorganized infants with a secondary secure attachment classification. Disorganized infants were more vulnerable to the effect of maternal postnatal depressive symptoms on the physiological stress systems., (Copyright © 2012 Society for Psychophysiological Research.)