Sleep and circadian rhythms during pregnancy, social disadvantage, and alterations in brain development in neonates.

Pregnant women in poverty may be especially likely to experience sleep and circadian rhythm disturbances, which may have downstream effects on fetal neurodevelopment. However, the associations between sleep and circadian rhythm disturbances, social disadvantage during pregnancy, and neonatal brain structure remains poorly understood. The current study explored the association between maternal sleep and circadian rhythm disturbances during pregnancy and neonatal brain outcomes, examining sleep and circadian rhythm disturbances as a mediator of the effect of social disadvantage during pregnancy on infant structural brain outcomes. The study included 148 mother-infant dyads, recruited during early pregnancy, who had both actigraphy and neuroimaging data. Mothers' sleep was assessed throughout their pregnancy using actigraphy, and neonates underwent brain magnetic resonance imaging in the first weeks of life. Neonatal structural brain outcomes included cortical gray matter, subcortical gray matter, and white matter volumes along with a measure of the total surface area of the cortex. Neonates of mothers who experienced greater inter-daily deviations in sleep duration had smaller total cortical gray and white matter volumes and reduced cortical surface areas. Neonates of mothers who had higher levels of circadian misalignment and later sleep timing during pregnancy showed smaller subcortical gray matter volumes. Inter-daily deviations in sleep duration during pregnancy mediated the association between maternal social disadvantage and neonatal structural brain outcomes. Findings highlight the importance of regularity and rhythmicity in sleep schedules during pregnancy and bring to light the role of chronodisruption as a potential mechanism underlying the deleterious neurodevelopmental effects of prenatal adversity. RESEARCH HIGHLIGHTS: Social disadvantage was associated with sleep and circadian rhythm disturbances during pregnancy, including later sleep schedules, increased variability in sleep duration, circadian misalignment, and a higher proportion of the sleep period spent awake. Maternal sleep and circadian rhythm disturbances during pregnancy were associated with decreased brain volume and reduced cortical surface area in neonates. Maternal inter-daily deviations in sleep duration during pregnancy mediated the association between social disadvantage and neonatal brain volume and cortical surface area.

Less attention to emotional faces is associated with low empathy and prosociality in 12-to 20-month old infants.

The development of empathy and prosocial behavior begins in infancy and is likely supported by emotion processing skills. The current study explored whether early emerging deficits in emotion processing are associated with disruptions in the development of empathy and prosociality. We investigated this question in a large, diverse sample of 147, 11- to 20-month-old infants (42% female; 61% Black; 67% low socioeconomic status). Infants completed two observational tasks assessing prosocial helping and one task assessing empathy and prosocial comforting behavior. Infants also completed an eye-tracking task assessing engagement and disengagement with negative emotional faces. Infants who attended less to angry, sad, and fearful faces (i.e., by being slower to look at and/or quicker to look away from negative compared to neutral faces) engaged in fewer helping behaviors, and effect sizes were larger when examining infants' attention toward the eye regions of faces. Additionally, infants who were quicker to look away from the eye regions of angry faces, but not the whole face, displayed less empathy and comforting behaviors. Results suggest that as early as 12 months of age, infants' decreased attention toward negative emotional faces, particularly the eye regions, is associated with less empathy and prosociality during a developmental period in which these abilities are rapidly maturing.

Associations of observed callous-unemotional behaviors in early childhood with conduct problems and substance use over 14 years.

Callous-unemotional (CU) behaviors (i.e., low concern and active disregard for others) uniquely predict severe conduct problems and substance use when present by late childhood. Less is known about the predictive utility of CU behaviors displayed in early childhood, when morality is developing and interventions may be more effective. Children aged 4-7 years (N = 246; 47.6% girls) completed an observational task wherein they were encouraged to tear an experimenter's valued photograph, and blind raters coded children's displayed CU behaviors. During the next 14 years, children's conduct problems (i.e., oppositional defiant and conduct symptoms) and age of onset of substance use were assessed. Compared to children displaying fewer CU behaviors, children displaying greater CU behaviors were 7.61 times more likely to meet criteria for a conduct disorder (n = 52) into early adulthood (95% CI, 2.96-19.59; p = <.0001), and their conduct problems were significantly more severe. Greater CU behaviors were associated with earlier onset of substance use (B = -.69, SE = .32, t = -2.14, p = .036). An ecologically valid observed indicator of early CU behavior was associated with substantially heightened risk for conduct problems and earlier onset substance use into adulthood. Early CU behavior is a powerful risk marker identifiable using a simple behavioral task which could be used to target children for early intervention.

Developmental pathways from preschool temper tantrums to later psychopathology.

Temper tantrums are sudden, overt negative emotional displays that are disproportionate to the eliciting event. Research supports that severe temper tantrums during the preschool period are associated with preschool psychopathology, but few studies have identified which characteristics of preschool tantrums are predictive of distal psychopathological outcomes in later childhood and adolescence. To examine this question, we used a prospective, longitudinal dataset enriched for early psychopathology. Participants (N = 299) included 3-to 6-year-old children (47.8% female) assessed for tantrums and early childhood psychopathology using diagnostic interviews and then continually assessed using diagnostic interviews over 10 subsequent time points throughout childhood and adolescence. We identified two unique groupings of tantrum behaviors: aggression towards others/objects (e.g., hitting others) and aggression towards self (e.g., hitting self). While both types of tantrum behaviors were associated with early childhood psychopathology severity, tantrum behaviors characterized by aggression towards self were more predictive of later psychopathology. Children displaying high levels of both types of tantrum behaviors had more severe externalizing problems during early childhood and more severe depression and oppositional defiant disorder across childhood and adolescence. Findings suggest that tantrum behaviors characterized by aggression towards self are particularly predictive of later psychopathology.

Children's Sleep and Externalizing Problems: A Day-to-day Multilevel Modeling Approach.

BACKGROUND: Sleep problems and externalizing problems tend to be positively associated, but the direction of this association is unclear. METHOD: Day-to-day associations between sleep and behavior were examined in children (N = 22) ages 3-8 with clinical levels of externalizing problems. These children were enrolled in Parent Management Training and behavioral sleep intervention. During assessments before and after treatment, children wore actigraphs for seven days and parents concurrently completed sleep diaries and daily tallies of noncompliance, aggression, and tantrums. Multilevel modeling was used to account for the nested structure of the data, at the day-to-day level (level 1), within assessment points (level 2), and within children (level 3). RESULTS: Late sleep timing and fragmentation were predictive of next-day noncompliance and tantrums, respectively. There were fewer associations for a given day's behavior predicting that night's sleep, although children who showed more aggression and noncompliance at baseline tended to have later bedtimes and sleep onset times compared to other children.

Picky Eating in Childhood: Associations With Obsessive-Compulsive Symptoms.

OBJECTIVE: To test whether childhood picky eating (PE)-a behavior previously linked to many forms of psychopathology-is specifically associated with symptoms of obsessive-compulsive disorder (OCD). METHODS: We investigated the relationship between PE and symptoms of several forms of psychopathology in two separate observational samples: a sample of 110 children (5 and 6 years old) and a sample of 210 children (8 and 9 years old) drawn from a longitudinal study. In each sample, regression models based on psychiatric symptoms or diagnoses were used to assess the specificity of PE associations while accounting for cooccurring symptoms or comorbidities. RESULTS: Although bivariate associations emerged between PE and multiple forms of psychopathology, multivariate analyses revealed these associations were driven by a strong and specific association between PE and symptoms of OCD in both samples. Moreover, PE among 8- and 9-year-olds in the longitudinal study predicted emergence of additional later psychopathology, specifically attention-deficit/hyperactivity disorder (ADHD). CONCLUSIONS: Findings suggest that PE, an easily identifiable clinical presentation, is also a specific marker for obsessive-compulsive symptomatology in school-age children and may impart risk for ADHD later in childhood.

Getting in synch: Unpacking the role of parent-child synchrony in the development of internalizing and externalizing behaviors.

While substantial research supports the role of parent-child interactions on the emergence of psychiatric symptoms, few studies have explored biological mechanisms for this association. The current study explored behavioral and neural parent-child synchronization during frustration and play as predictors of internalizing and externalizing behaviors across a span of 1.5 years. Parent-child dyads first came to the laboratory when the child was 4-5 years old and completed the Disruptive Behavior Diagnostic Observation Schedule: Biological Synchrony (DB-DOS: BioSync) task while functional near-infrared spectroscopy (fNIRS) data were recorded. Parents reported on their child's internalizing and externalizing behaviors using the Child Behavior Checklist (CBCL) four times over 1.5 years. Latent growth curve (LGC) modeling was conducted to assess neural and behavioral synchrony as predictors of internalizing and externalizing trajectories. Consistent with previous investigations in this age range, on average, internalizing and externalizing behaviors decreased over the four time points. Parent-child neural synchrony during a period of play predicted rate of change in internalizing but not externalizing behaviors such that higher parent-child neural synchrony was associated with a more rapid decrease in internalizing behaviors. Our results suggest that a parent-child dyad's ability to coordinate neural activation during positive interactions might serve as a protective mechanism in the context of internalizing behaviors.

The Family Context of Toddler Sleep: Routines, Sleep Environment, and Emotional Security Induction in the Hour before Bedtime.

Family processes during the pre-bedtime period likely have a crucial influence on toddler sleep, but relatively little previous research has focused on family process in this context. The current study examined several aspects of family process during the pre-bedtime period, including the use of bedtime routines, the qualities of the child's home sleep environment, and the promotion of child emotional security, in families of 30-month-old toddlers (N= 546; 265 female) who were part of a multi-site longitudinal study of toddler development. These characteristics were quantified using a combination of parent- and observer-reports and examined in association with child sleep using correlation and multiple regression. Child sleep was assessed using actigraphy to measure sleep duration, timing, variability, activity, and latency. Bedtime routines were examined using parents' daily records. Home sleep environment and emotional security induction were quantified based on observer ratings and in-home observation notes, respectively. All three measures of pre-bedtime context (i.e., bedtime routine inconsistency, poor quality sleep environments, and emotional security induction) were correlated with various aspects of child sleep (significant correlations:.11-.22). The most robust associations occurred between the pre-bedtime context measures and sleep timing (i.e., the timing of the child's sleep schedule) and variability (i.e., night to night variability in sleep timing and duration). Pre-bedtime variables, including bedtime routine consistency, home sleep environment quality, and positive emotional security induction, also mediated the association between family socioeconomic status and child sleep. Our findings underscore the value of considering family context when examining individual differences in child sleep.

Sleep problems in preschool-onset major depressive disorder: the effect of treatment with parent-child interaction therapy-emotion development.

In school-aged children, adolescents, and adults, more than 72% of individuals diagnosed with major depression report co-occurring sleep problems, but little is known about sleep problems in the context of preschool-onset major depressive disorder (PO-MDD). The current study examined the prevalence of various sleep problems in a sample of young children diagnosed with PO-MDD and explored how the treatment of depression, using a modification of parent-child interaction therapy focused on emotional development (PCIT-ED), affects sleep problems. Participants included 229 preschoolers (ages 3-6 years) who met criteria for PO-MDD and participated a single-blind, randomized control trial comparing PCIT-ED to a waitlist control condition. Children were randomly assigned to either PCIT-ED (n = 114) or the waitlist condition (n = 115). Children were assessed at baseline, immediately after PCIT-ED, and 3 months after treatment completion for parent-reported sleep problems across the domains of insomnia, hypersomnia, daytime fatigue, and a total sleep problem index. In our sample, 45% of children had at least one subthreshold sleep problem, 38.4% had at least one threshold sleep problem, and 72.5% had at least one sleep problem (either threshold or subthreshold). Treatment with PCIT-ED significantly reduced sleep problems, including insomnia, daytime fatigue, and total sleep problems, compared to a waitlist condition, even when controlling for child depression. This reduction was maintained at a 3-month follow-up. Sleep problems are a prevalent co-occurring condition with PO-MDD. Interventions such as PCIT-ED that also effectively reduce sleep problems may be particularly beneficial for recovery from PO-MDD.Clinical trial registration information: a randomized control trial of PCIT-ED for preschool depression; https://clinicaltrials.gov/NCT02076425 .

Sleep across early childhood: implications for internalizing and externalizing problems, socioemotional skills, and cognitive and academic abilities in preschool.

BACKGROUND: Sleep is thought to be important for behavioral and cognitive development. However, much of the prior research on sleep's role in behavioral/cognitive development has relied upon self-report measures and cross-sectional designs. METHODS: The current study examined how early childhood sleep, measured actigraphically, was developmentally associated with child functioning at 54 months. Emphasis was on functioning at preschool, a crucial setting for the emergence of psychopathology. Participants included 119 children assessed longitudinally at 30, 36, 42, and 54 months. We examined correlations between child sleep and adjustment across three domains: behavioral adjustment (i.e., internalizing and externalizing problems), socioemotional skills, and academic/cognitive abilities. We further probed consistent associations with growth curve modeling. RESULTS: Internalizing problems were associated with sleep variability, and cognitive and academic abilities were associated with sleep timing. Growth curve analysis suggested that children with more variable sleep at 30 months had higher teacher-reported internalizing problems in preschool and that children with later sleep timing at 30 months had poorer cognitive and academic skills at 54 months. However, changes in sleep from 30 to 54 months were not associated with any of the domains of adjustment. CONCLUSIONS: Findings indicate that objectively measured sleep variability and late sleep timing in toddlerhood are associated with higher levels of internalizing problems and poorer academic/cognitive abilities in preschool.

Child Sleep and Socioeconomic Context in the Development of Cognitive Abilities in Early Childhood.

Despite a robust literature examining the association between sleep problems and cognitive abilities in childhood, little is known about this association in toddlerhood, a period of rapid cognitive development. The present study examined the association between various sleep problems, using actigraphy, and performance on a standardized test of cognitive abilities, longitudinally across three ages (30, 36, and 42 months) in a large sample of toddlers (N = 493). Results revealed a between-subject effect in which the children who had more delayed sleep schedules on average also showed poorer cognitive abilities on average but did not support a within-subjects effect. Results also showed that delayed sleep explains part of the association between family socioeconomic context and child cognitive abilities.

Diminished Neural Responses to Emotionally Valenced Facial Stimuli: A Potential Biomarker for Unemotional Traits in Early Childhood.

Callous-unemotional (CU) traits are characterized by deficits in guilt/empathy, shallow affect, and the callous and manipulative use of others. Individuals showing CU traits have increased risk for behavior problems and reduced responses to displays of distress in others. To explore how deficits in emotion-processing are associated with CU traits, the current study examined the association between callous-unemotionality and a neural index of facial emotion processing, using the event-related potential technique in a group of 3-5 year olds. Children viewed a series of static emotional faces, depicting either fear or happiness, while electroencephalography data were collected. The N170 component, thought to index the neural processes associated with face perception, was examined along with CU traits. Findings suggest that the unemotional dimension of CU traits is associated with diminished emotion-processing responses to fearful faces. Reduced neural responses to facial depictions of fear could be a biomarker for unemotional traits in early childhood.

A longitudinal, within-person investigation of the association between the P3 ERP component and externalizing behavior problems in young children.

BACKGROUND: Externalizing problems, including aggression and conduct problems, are thought to involve impaired attentional capacities. Previous research suggests that the P3 event-related potential (ERP) component is an index of attentional processing, and diminished P3 amplitudes to infrequent stimuli have been shown to be associated with externalizing problems and attention-deficit/hyperactivity disorder (ADHD). However, the vast majority of this prior work has been cross-sectional and has not examined young children. The present study is the first investigation of whether within-individual changes in P3 amplitude predict changes in externalizing problems, providing a stronger test of developmental process. METHOD: Participants included a community sample of children (N = 153) followed longitudinally at 30, 36, and 42 months of age. Children completed an oddball task while ERP data were recorded. Parents rated their children's aggression and ADHD symptoms. RESULTS: Children's within-individual changes in the P3 amplitude predicted concomitant within-child changes in their aggression such that smaller P3 amplitudes (relative to a child's own mean) were associated with more aggression symptoms. However, changes in P3 amplitudes were not significantly associated with ADHD symptoms. CONCLUSIONS: Findings suggest that the P3 may play a role in development of aggression, but do not support the notion that the P3 plays a role in development of early ADHD symptoms.

Reduced neural responses to vocal fear: a potential biomarker for callous-uncaring traits in early childhood.

OBJECTIVE: Callous-unemotional (CU) traits are characterized by a lack of guilt and empathy, and low responsiveness to distress and fear in others. Children with CU traits are at-risk for engaging in early and persistent conduct problems. Individuals showing CU traits have been shown to have reduced neural responses to others' distress (e.g., fear). However, the neural components of distress responses in children with CU traits have not been investigated in early childhood. In the current study, we examined neural responses that underlie the processing of emotionally valenced vocal stimuli using the event-related potential technique in a group of preschoolers. METHOD: Participants between 2 and 5 years old took part in an auditory oddball task containing English-based pseudowords spoken with either a fearful, happy, or a neutral prosody while electroencephalography data were collected. The mismatch negativity (MMN) component, an index of the automatic detection of deviant stimuli within a series of stimuli, was examined in association with two dimensions of CU traits (i.e., callousness-uncaring and unemotional dimensions) reported by primary caregivers. RESULTS: Findings suggest that the callousness-uncaring dimension of CU traits in early childhood is associated with reduced responses to fearful vocal stimuli. CONCLUSIONS: Reduced neural responses to vocal fear could be a biomarker for callous-uncaring traits in early childhood. These findings are relevant for clinicians and researchers attempting to identify risk factors for early callous-uncaring traits.

Day-to-day bidirectional associations between sleep and emotion states in early childhood: Importance of end-of-day mood for sleep quality.

OBJECTIVES: Poor quality sleep can impact emotions and emotion regulation, resulting in a "sleep-mood" cycle where poor sleep affects mood and vice-versa. This relationship is poorly understood during early childhood, when sleep patterns and emotion displays are rapidly changing. This study aimed to understand the day-to-day effects of poor sleep on emotions in preschoolers by using objective (actigraphy) and subjective (ecological momentary assessment) measures to assess both between- and within-child effects. We hypothesized that disrupted sleep would lead to affect disruptions and vice versa. METHODS: This study included 133 preschoolers and their caregivers recruited from the community. Children's sleep was measured via actigraphy (ActiGraph GT3X+) across 1week. Affect was collected concurrently via caregiver report during an ecological momentary assessment protocol. Caregivers reported on their child's affect four times per day: morning, afternoon, early evening, and before bed. RESULTS: Multilevel modeling analyses revealed that children with sleep disturbances displayed less positive affect overall, more negative affect in the evenings, and alterations in positive affect lability, and that daytime affect was associated with subsequent nighttime sleep. Within-child associations also showed fluctuations in positive affect correlated with shorter sleep durations and later bedtimes. CONCLUSIONS: This study identified both between- and within-child associations between sleep and affect in early childhood, revealing a dynamic and reciprocal relationship between the two. These findings highlight the importance of considering both sleep and affect in early childhood interventions, as promoting positive affect may enhance sleep quality and vice versa.

Preadolescent Suicidal Thoughts and Behaviors: An Intensive Longitudinal Study of Risk Factors.

OBJECTIVE: Dramatic increases in rates of suicidal thoughts and behaviors (STBs) among youth highlight the need to pinpoint early risk factors. This study used intensive longitudinal sampling to assess what the concurrent associations were between risk factors and STB status, how proximal changes in risk factors were related to STB status, and how risk factors prospectively predicted changes in STB status in a preadolescent sample enriched for early childhood psychopathology. METHOD: A total of 192 participants were included from the Parent-Child Interaction Therapy-Emotional Development (PCIT-ED) Study, a longitudinal study of children with and without preschool depression. Participants 7 to 12 years of age completed a diagnostic interview, followed by 12 months of intensive longitudinal sampling, assessing experiences of suicidal ideation and 11 psychosocial variables with known links to STBs in adolescents and adults. Preadolescents with STB history (high-risk) received surveys weekly, and those without STB history (lower-risk) received surveys monthly. RESULTS: Female sex, elevated depressive symptoms, greater use of expressive suppression and rumination, emotional clarity, and perceived burdensomeness were uniquely concurrently associated with the likelihood of STB endorsement. Within the high-risk group, (1) increases in depression, expressive suppression, rumination, and perceived burdensomeness, and decreases in positive affect from weekt to weekt+1 were associated with a higher likelihood of a positive STB status at weekt+1; and (2) higher expressive suppression, perceived burdensomeness, and caregiver criticism and conflict at weekt compared to participants' mean levels prospectively predicted increases in the likelihood of a positive STB report from weekt to weekt+1. CONCLUSION: Psychosocial factors influencing STBs in adolescents and adults also affect preadolescents in day-to-day life. Expressive suppression and perceived burdensomeness consistently emerged as novel risk indicators and potential targets for treatment. In addition, increases in depression, rumination, and caregiver criticism and conflict, as well as decreases in positive affect, might prompt heightened STB screening and assessments for preadolescents with a history of STBs.

Sensory Over-responsivity: A Feature of Childhood Psychiatric Illness Associated With Altered Functional Connectivity of Sensory Networks.

BACKGROUND: Sensory over-responsivity (SOR) is recognized as a common feature of autism spectrum disorder. However, SOR is also common among typically developing children, in whom it is associated with elevated levels of psychiatric symptoms. The clinical significance and neurocognitive bases of SOR in these children remain poorly understood and actively debated. METHODS: This study used linear mixed-effects models to identify psychiatric symptoms and network-level functional connectivity (FC) differences associated with parent-reported SOR in the Adolescent Brain Cognitive Development (ABCD) Study, a large community sample (9 to 12 years of age) (N = 11,210). RESULTS: Children with SOR constituted 18% of the overall sample but comprised more than half of the children with internalizing or externalizing scores in the clinical range. Controlling for autistic traits, both mild and severe SOR were associated with greater concurrent symptoms of depression, anxiety, obsessive-compulsive disorder, and attention-deficit/hyperactivity disorder. Controlling for psychiatric symptoms and autistic traits, SOR predicted increased anxiety, attention-deficit/hyperactivity disorder, and prodromal psychosis symptoms 1 year later and was associated with FC differences in brain networks supporting sensory and salience processing in datasets collected 2 years apart. Differences included reduced FC within and between sensorimotor networks, enhanced sensorimotor-salience FC, and altered FC between sensory networks and bilateral hippocampi. CONCLUSIONS: SOR is a common, clinically relevant feature of childhood psychiatric illness that provides unique predictive information about risk. It is associated with differences in brain networks that subserve tactile processing, implicating a neural basis for sensory differences in affected children.

Early childhood sleep problems predict increased risk for the later development of suicidal thoughts.

Suicidal thoughts and behaviors in youth are an escalating and immediate public health concern. To better understand youth suicidal thoughts and behaviors, it is important to identify risk factors in early childhood that predict the later emergence of youth suicidal thoughts and behaviors. Research with adults and adolescents has identified sleep disturbances as a risk factor for suicidal thoughts and behaviors, but this has yet to be examined in early childhood. Using a prospective, 17-year longitudinal design, the current study explored the association between early childhood sleep disturbances and concurrent and later suicidal thoughts and behaviors (in separate models) across childhood and adolescence. Results indicate that sleep problems in early childhood are associated with increased probability for suicidal thoughts after age 8, even when controlling for prior and concurrent depression severity. Our findings suggest that early childhood sleep difficulties warrant increased clinical attention and management, as they may contribute to the maintenance and exacerbation of suicidal thoughts over time. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Sleep and Negative Affect Across Toddlerhood in the Context of Stress.

Negative affect is associated with both high stress and poor sleep, but questions remain about the direction of these associations across time and interactions between stress and sleep, especially in early childhood. The present study examined sleep deficits, family stress, and observed negative affect in a sample of toddlers at 30, 36, and 42 months (N = 504). Negative affect was observed during a parent-child free play task. Sleep was measured via actigraphy. Stress was measured using a cumulative risk index of socioeconomic status, single parent status, household chaos, role overload, parenting hassles, social support, and stressful events. Findings showed few associations between sleep and negative affect, except for toddlers experiencing high levels of family stress. Toddlers experiencing both high stress and poor sleep demonstrated the highest levels of negative affect in the lab at 30 months. Adequate sleep may serve as a protective factor for children in high-stress families.

The physical home environment and sleep: What matters most for sleep in early childhood.

The physical home environment is thought to play a crucial role in facilitating healthy sleep in young children. However, relatively little is known about how various features of the physical home environment are associated with sleep in early childhood, and some of the recommendations clinicians make for improving child sleep environments are based on limited research evidence. The present study examined how observer and parent descriptions of the child's physical home environment were associated with child sleep, measured using actigraphy and parent's reports, across a year in early childhood. The study used a machine learning approach (elastic net regression) to specify which aspects of the physical home environment were most important for predicting five aspects of child sleep, sleep duration, sleep variability, sleep timing, sleep activity, and latency to fall asleep. The study included 546 toddlers (265 females) recruited at 30 months of age and reassessed at 36 and 42 months of age. Poorer quality physical home environments were associated with later sleep schedules, more variable sleep schedules, shorter sleep durations, and more parent-reported sleep problems in young children. The most important environmental predictors of sleep were room sharing with an adult, bed sharing, and quality of both the child's sleep space and the wider home environment. (PsycInfo Database Record (c) 2022 APA, all rights reserved).