Sleep Architecture in Infants of Substance‐Abusing Mothers

This longitudinal, year‐long study compared sleep–wake state organization in two groups of infants–infants whose mothers abused substances during their pregnancies and nonexposed, typically developing, age‐matched comparison infants–to determine whether differences in sleep–wake state organization existed between the two groups. Seventeen infants of mothers who were participating in a parent–infant residential treatment program for substance abuse were enrolled. Their sleep–wake state organization over the first year of life was compared to that of 17 age‐matched comparison infants. The intent was to follow each infant on five occasions over the first year of life using established methods of time‐lapse videosomnography to record sleep–wake state organization; however, attrition in the substance‐abusing group was problematic. Some sleep–wake variables (i.e., Active Sleep%, Quiet Sleep%, Awake%, number of nighttime awakenings) were similar for both groups of infants at comparable ages across the first year. Total sleep time and the longest sustained sleep period (sleep continuity variables) differed significantly at some of the ages measured. Although overall sleep architecture appears highly resilient and well organized, some indications of sleep fragmentation and shortened nighttime sleep periods were observed in the substance‐exposed infants. More research is needed to explain why sleep‐continuity variables and not sleep‐state proportion variables differed between the two groups.     

The behavioural treatment of sleep difficulties in children with an intellectual disability

Reinforcement, instruction giving, partner support strategies, bedtime routine, and standard extinction were taught to the parents of three boys (aged 5–10 years) with an intellectual disability and sleeping difficulties. Sleep was measured using sleep diaries and actigraphy, and daytime behaviour was monitored using diaries and direct observation. At referral, all children needed a parent present to fall asleep, two had co‐sleeping difficulties, and two had night waking difficulties. At post‐intervention, all children were falling asleep independently, co‐sleeping was eliminated for two children, and night waking was reduced in one child. An extinction burst was experienced by two children, with one family putting their child back to bed 259 times on the first night. Though one child still had night waking difficulties following intervention, actigraph recording demonstrated an improvement in his sleep quality. In addition to the children's independence, improvements were seen for sleep length, sleep latency, and morning wake time. However, improvements in daytime behaviour showed inconsistency across behaviours and settings. Improvement in sleep was maintained at a three month follow‐up. It was concluded that using extinction to address sleep problems in children with an intellectual disability is effective and approved of by parents, but any impact on daytime behaviour is equivocal. Copyright © 2002 John Wiley & Sons, Ltd.     

Development of sleep/wake,activity and temperature rhythms in newborns maintained in a neonatal intensive care unit and the impact of feeding schedules

Biological rhythms in infants are described as evolving from an ultradian to a circadian pattern along the first months of life. Recently, the use of actigraphy and thermistors with memory has contributed to the understanding of temporal relations of different variables along development. The aim of this study was to describe and compare the development of the rhythmic pattern of wrist temperature, activity/rest cycle, sleep/wake and feeding behavior in term and preterm newborns maintained in a neonatal intensive care unit (NICU).MethodsNineteen healthy preterm and seven fullterm newborns had the following variables monitored continuously while they were in the NICU: activity recorded by actigraphy, wrist temperature recorded with a thermistor and observed sleep and feeding behavior recorded by the NICU staff with diaries. Subjects were divided in 3 groups according to their gestational age at birth and rhythmic parameters were compared.ResultsA dominant daily rhythm was observed for wrist temperature since the first two weeks of life and no age relation was demonstrated. Otherwise, a daily pattern in activity/rest cycle was observed for most preterm newborns since 35 weeks of postconceptional age and was more robust in term babies. Feeding and sleep/wake data showed an almost exclusive 3 h rhythm, probably related to a masking effect of feeding schedules.ConclusionsWe found that wrist temperature develops a daily pattern as soon as previously reported for rectal temperature, and with acrophase profile similar to adults. Moreover, we were able to find a daily rhythm in activity/rest cycle earlier than previously reported in literature. We also suggest that sleep/wake rhythm and feeding behavior follow independent developmental courses, being more suitable to masking effects.     

Crawling in and out of sleep

The goal of the study was to examine the link between motor attainments and sleep–wake regulation by comparing the sleep characteristics of infants who are crawling with the sleep of same‐age infants who have not yet acquired the locomotion milestone. The participants were 59 healthy 8‐month‐old infants with no developmental delays, who were recruited through well‐baby clinics and childcare centers. The measurements included objective sleep recordings (actigraphy), sleep questionnaire, and motor milestones checklist. The main finding was that the sleep of crawlers was more fragmented in comparison to the sleep of pre‐crawlers. While the findings of this report give support to the hypothesized link between sleep regulation and motor development, more studies are needed to clarify why crawling might provide a marker of nightwaking. In discussing the results, it is proposed that the association between fragmented sleep and crawling could be related to maturational, constitutional, and relational factors. Copyright © 2005 John Wiley & Sons, Ltd.     

Sleep patterns of 7‐week‐old infants at familial risk for attention deficit hyperactivity disorder

Sleep patterns of 26 seven‐week‐old boys at familial risk for attention deficit hyperactivity disorder (ADHD) and 18 control infants were compared by objective (actigraph) and subjective (maternal sleep diary) measures, over five consecutive 24‐hr periods. Actigraph findings indicated that the groups differed on stability (SD) of quiet sleep only during the day. Reports in maternal sleep diaries indicated that they also differed on stability of waking and stability of sleep duration, again only during the day. No group differences were found in terms of average scores, whether calculated for the entire 24‐hr periods, for nights, or for days. Mothers in the risk group reported that fathers were less involved in infant care than did those in the control group. These findings suggest that as early as 7 weeks of age, infants at risk for ADHD differ from controls only on stability of their sleep patterns during the day, when environmental regulatory factors are more intensive.     

Cognitive Behavioral Treatment for Insomnia in Veterans with Long-Standing Posttraumatic Stress Disorder: A Pilot Study

This uncontrolled pilot study assessed the effects of cognitive behavioral therapy for insomnia in veterans with long-standing posttraumatic stress disorder. Male veterans with current chronic insomnia and PTSD (n?=?8; M age = 58.6, SD?=?3.0; 87.5% African American, 12.5% European American; 87.5% Vietnam Veterans, 12.5% 1st Gulf War Veterans) reported a trauma related to their military service. Participants appeared for five weekly individual sessions of cognitive behavioral therapy for insomnia and completed one-week assessments of objective sleep (actigraphy) and subjective sleep (sleep diaries), the Insomnia Severity Index, and measures of functioning, posttraumatic stress disorder, and psychological distress both before and after treatment. Paired t tests revealed significant posttreatment improvements for various subjective assessments of sleep patterns but actigraphy-defined sleep was unchanged. Measures of functioning, nightmares, and posttraumatic stress disorder severity were also unchanged at posttreatment. Preliminary results were encouraging in improving subjective perceptions of sleep in individuals with posttraumatic stress disorder, warranting further study with more rigorous methodology.     

A time series analysis of the relation between motor skill acquisition and sleep in infancy

To systematically examine the relation between motor milestone onset and disruption of night sleep in infancy, three families kept microgenetic, prospective, daily checklist diaries of their infants’ motor behavior and sleep (197-313 observation days; 19,000 diary entries). Process control and interrupted time series analyses examined whether deviations from the moving average for night wakings and evening sleep duration were temporally linked to motor skill onset and tested for meaningful differences in individual sleep patterns before and after skill onset. Model assumptions defined skill onset as first day of occurrence or as mastery and moving average windows as 3, 7, or 14 days. Changes in infants’ sleep patterns were associated with changing expertise for motor milestones. The temporal relation varied depending on infant and sleep parameter. Intensive longitudinal data collection may increase our understanding of micro-events in infant development.     

Sleep disruption and motor development: Does pulling-to-stand impacts sleep–wake regulation?

During the second half of the 1st year, periods of increased sleep disruption have been documented alongside overall improvement in sleep–wake regulation. The objective of the present research was to test if pulling-to-stand (PTS), a milestone typically achieved during the latter part of the 1st year, co-occurs with a period of disrupted sleep. In a longitudinal design, 20 healthy infants were followed-up, from 7 to 11–12 months, at 3-week intervals. Each measurement consisted of filmed motor observations and sleep recordings (actigraphy), both conducted at home. It was found that among early achievers of PTS (by 8 months), the milestone was time-linked to a period of disrupted sleep. The results point to the significance of timing in the interplay between domains of development, and highlight the importance of considering both chronological and developmental metrics in studying changes in sleep–wake regulation.     

Mother–child interaction and sleep regulation in one‐year‐olds

The regulation of sleep–wake states is controlled not only by biological mechanisms but by care‐giving context as well. In this study the association between mother–child relationship and the infant's sleep was examined. Thirty‐seven 12‐month‐olds and their mothers participated in a 10‐minute laboratory play episode. The dyadic interaction was coded with the Early Parent–Child Relational Assessment (Clark, 1985) and with the Emotional Availability scales (Biringen, Robinson, & Emde, 1993). The child's sleep was measured at home with a small‐computerized activity monitor. Although mothers' behavior was not related to the child's sleep, infants who were more responsive in the play episode woke up more frequently compared to infants who were less involved in the interaction. The link between social‐emotional competency and fragmented sleep, among nonrisk infants, could be an age‐related phenomenon. ©2001 Michigan Association for Infant Mental Health.     

Comparison of Motionlogger Watch and Actiwatch actigraphs to polysomnography for sleep/wake estimation in healthy young adults

Sleep/wake identification and sleep parameter estimates from Motionlogger Watch and Actiwatch-64 actigraphs were compared to polysomnography (PSG). Following one night of baseline sleep, 29 volunteers remained awake for 36 h, followed by 11 h of recovery sleep in the laboratory. Two sets of analyses were performed: (1) epoch-by-epoch agreement and discriminability index (d') calculations, and (2) sleep parameter concordance with repeated measures ANOVAs. Sensitivity (sleep identification), specificity (wake detection), and overall agreement with PSG, as well as d', were higher for the Motionlogger than for Actiwatch. Relative to PSG, the Actiwatch-estimated total sleep time and sleep efficiency were underestimated and the number of awakenings was overestimated for baseline and recovery; sleep latency was underestimated on the baseline night. On the other hand, the Motionlogger-estimated total sleep time and sleep efficiency estimates were underestimated, and the sleep latency was overestimated on recovery, versus PSG. Despite these misestimations, it was concluded that the Motionlogger provided nominally better agreement with PSG, and that actigraphy generally constitutes a reasonably reliable tool for producing objective measurements of sleep/wake, but that users should remain mindful of its limitations.     

Maternal perceptions of the sleep patterns of premature infants at seven months corrected age compared to full-term infants

It has been reported that 83%–87% of full-term infants regularly sleep through the night (from midnight to 5 a.m.) by 6 months of age, but there is little information about the sleep patterns of premature infants. The purpose of the current study was to identify maternal perceptions of the sleep patterns of premature infants. Parents of 32 premature infants with birth weight below 1,750 gm and of 13 full-term infants completed a 24-hour sleep record in 30-minute epochs for 1 week at 7 months of chronological (term) or corrected age (premature). Mean birth weight of premature infants was 1,278 ± 340 gm, with a gestational age of 30.4 ± 2.7 weeks. The daily total sleep time, longest sleep segment, frequency of sleep-wake transitions, and percentage of night sleep (8 p.m.–8 a.m.), averaged from the 1-week sleep record and number of night wakenings per week, were used as indicators of sleep patterns. The longest reported sleep segments of premature infants were significantly shorter than those of full-term infants (8.2 ± 2 hours versus 9.6 ± 1 hour, p < 0.01) and the number of night wakenings per week was significantly greater (3.13 ± 3 versus 0.54 ± 7, p < 0.005). Total reported sleep time, percentage of night sleep, and sleep-wake transitions did not differ significantly between premature and full-term infants. However, analysis of feeding events revealed that premature infants received significantly more feedings between midnight and 5 a.m. (M = 0.31 + 3 versus M = 0.06 + 1, p < 0.001). We conclude that sleep pattern diaries kept by parents indicate that premature infants have developed a diurnal sleep rhythm by 7 months corrected age, but they still have shorter sleep segments and they awaken more during the night than term infants.     

Exploring Socioeconomic Differences in Bedtime Behaviours and Sleep Duration in English Preschool Children

Children's sleep is critical for optimal health and development; yet sleep duration has decreased in recent decades, and many children do not have adequate sleep. Certain sleep behaviours (‘sleep hygiene’) are commonly recommended, and there is some evidence that they are associated with longer nighttime sleep. Parents of 84 British 3‐year‐old children were interviewed about their children's sleep and completed five‐night/four‐day sleep diaries documenting their children's sleep, from which daily sleep duration was estimated. Diaries were validated by actigraphy in a subgroup of children. Sleep hygiene behaviours (regular bedtime, reading at bedtime, falling asleep in bed) were associated with each other, and were more common in the high socioeconomic status compared to the low socioeconomic status group. Parents' reasons for not practicing sleep hygiene included difficulty, inability or inconvenience. Sleep hygiene behaviours were associated with significantly longer child sleep at night but not over 24 h. Longer daytime napping compensated for shorter nighttime sleep in children whose parents did not implement sleep hygiene behaviours. Parents may need to be advised that certain behaviours are associated with longer nighttime sleep and given practical advice on how to implement these behaviours. © 2014 The Authors. Infant and Child Development published by John Wiley & Sons, Ltd.     

My mother is sensitive,but I am too tired to know: Infant sleep as a moderator of prospective relations between maternal sensitivity and infant outcomes

This study investigated the moderating role of infant sleep in the connections between maternal sensitivity and three indicators of infant functioning: attachment security, theory of mind, and executive functioning (EF). Maternal sensitivity was assessed when infants (27 girls and 36 boys) were 1 year of age. Infant sleep was assessed with actigraphy at age 2; attachment security, theory of mind, and EF were also assessed at age 2. Results indicated that maternal sensitivity was positively related to attachment security only among infants who got more sleep at night, and to conflict-EF and theory of mind only for infants who got greater proportions of their sleep during the night. These results suggest that sleep may enhance the benefits of maternal sensitivity for some aspects of infants’ functioning, providing further support for the importance of sleep maturation as a salient developmental task of infancy.     

A test of the bidirectional association between sleep and mood in bipolar disorder and insomnia

The present study investigates sleep, mood, and the proposed bidirectional relationship between the two in psychiatric disorders. Participants with interepisode bipolar disorder (n = 49), insomnia (n = 34), and no psychiatric history (n = 52) completed seven consecutive days of sleep diaries and mood measures. The interepisode bipolar and insomnia participants exhibited greater sleep disturbance than the healthy control individuals. Negative mood was equally heightened in both interepisode bipolar disorder and insomnia, and there were no differences between the three groups in positive mood. Total wake time was associated with next morning negative mood in bipolar disorder, whereas evening negative mood was associated with subsequent total wake time in both bipolar disorder and insomnia. Additionally, positive mood was associated with subsequent total wake time for the insomnia group. Results support the theory that disruptions in nighttime sleep and daytime mood may be mutually maintaining and suggest the potential importance of transdiagnostic or universal processes.     

A cognitive-behavioral therapy for sleep-maintenance insomnia in older adults.

Older adults (3 men, 4 women, aged 55 to 68 years) with chronic sleep-maintenance insomnia were treated sequentially with relaxation therapy (RT) and then with a cognitive-behavioral therapy (CBT) specifically designed for alleviating sleep maintenance problems. Sleep diaries and an objective measure of sleep, the sleep assessment device, showed only modest improvements in measures of wake time after sleep onset, sleep efficiency, and night-to-night sleep variability following RT. However, significant improvements in these measures were observed following CBT and at a 3-month follow-up. These findings, considered in conjunction with previous reports, suggest that CBT specifically addresses factors that sustain sleep maintenance complaints. Additional trials of CBT with larger samples are warranted.     

Sleep patterns and sleep disruptions in kindergarten children

Assessed sleep patterns and sleep disruptions in kindergarten children and investigated the relation between sleep measures derived from objective and subjective evaluation methods. The sleep patterns of 59 normal kindergarten children (mean age = 5.5 years) were monitored for 4 to 5 consecutive nights by means of activity monitors (actigraph) and by means of parental daily sleep logs. The correlation between the actigraphic measures and the daily parental logs indicated that parents were accurate reporters of sleep schedule measures. However, parents were less accurate in assessing sleep quality measures, significantly underestimating the number of night-wakings and overestimating the quality of their children's sleep. Fragmented sleep was found, by means of activity monitoring, in 41% of the children.     

Yawning frequency and distribution in preterm and near term infants assessed throughout 24-h recordings

Yawning has been observed in foetuses and preterm infants. The aim of this study was to assess the frequency and the 24 h distribution of yawning in preterm infants.Twelve low-risk infants between 31 and 40 weeks of post-conceptional age (PCA) were continuously video-recorded for 24 h in their incubator. Spontaneous yawning was defined as opening of the mouth to its full extension in a dramatic stretch movement.The results showed that the rate of yawning across the 24-h period was 1.10/h. The highest incidence of yawns was in the waking motility pattern when compared to active sleep or quiet sleep motility patterns.Between 31 and 40 weeks, yawn incidence significantly decreased mainly during the day. The marked decrease in yawn frequency with age may be related to the development of circadian and homeostatic control of sleep and wake.     

Effects of nonnutritive sucking on state and activity: Term-preterm comparisons

The effects of ad libitum access to a pacifier on the behavioral state and motor activity of preterm infants have been compared with those observed in full-term neonates. Regardless of maturity, nonnutritive sucking (NNS) decreases the amount of time spent in active states and increases that spent in quiescent states, lengthens the longest state bout, and decreases the frequency of state transitions. NNS also reduces overall motor activity as well as that during Active Sleep. Provided such ad libitum sucking opportunity, preterm infants thus appear to derive no less benefit from NNS than do term neonates. This result contrasts with an earlier finding that preterms are less soothed by NNA than are term infants.     

Rhythmic organization of heart rate in breast-fed and bottle-fed newborn infants

Heart rates and behavioural states of 14 breast-fed and 14 bottlefed newborn infants were assessed every 30 seconds for 2 continuous hours. The 240 observations of heart rate were treated as time-series data and spectrum-analysed for behavioural rhythmicities. Of the 28 infants, 25 showed reliable cycles in heart rate; 22 of the 25 infants showed a dominant frequency with a 30–60 min periodicity, one that approximates the basic-rest activity cycle (BRAC). In addition to this basic cycle, additional higher frequency cycles in long-term heart rate variability were evident in the spectra of many infants. Breast-fed newborns had greater numbers of reliable cycles in heart rate than bottle-fed newborns. Further, breast-fed newborns had lower overall mean heart rates and lower mean heart rates in Quiet and Active Sleep states than bottle-fed newborns. Bottle-fed newborns were observed more often in Quiet Sleep than breast-fed newborns. Without knowledge of the specific mechanisms causing these behavioural differences, the results of this study suggest that the context in which breast-feeding occurs results in a more complex and energy-efficient pattern of behavioural organization than the context of bottle-feeding.     

Infant sleep-wake behaviors at two weeks,three and six months

Although infant sleep-wake behavior presents several developmental changes during the first six months, literature lacks on reference values and few studies have explored the role of individual change and stability on infant sleep-wake behavior during the first six months. This study aimed (1) to describe infant sleep-wake behaviors during the 24-h period, day and night, at two weeks, three, and six months, (2) and to explore developmental changes and the role of individual change and stability on infant sleep-wake behaviors from two weeks to six months. Ninety-four primiparous mothers completed measures on infant sleep-wake behaviors at two weeks, three and six months. Significant developmental changes were found on infant sleep-wake behaviors from two weeks to six months. Two-week-old infants sleep 13.3 h, spend 8.7 h awake, awake 6.1 times, have 0.4 h of latency to sleep, and 3.2 h of longest sleep period. Three-month-old infants sleep 13.0 h, spend 9.2 h awake, awake 5.5 times, have 0.4 h of latency to sleep, and 5.2 h of longest sleep period. Six-month-old infants sleep 12.2 h, spend 10.0 h awake, awake 5.2 times, have 0.4 h of latency to sleep, and 5.6 h of longest sleep period. Significant individual change and stability were also found on infant sleep-wake behaviors from two weeks to six months. Despite significant developmental and individual changes, individual stability explains a significant amount of the variance on infant sleep-wake behaviors over the first six months of life.