Sleep Problems in Early Childhood

Sleep problems in infants and young children are one of the most common concerns raised by parents. A sleep problem can be defined as any sleep pattern that impedes the reinvigorating nature of sleep, or interferes with the sleep of others (Adair & Bauchner, 1993). These sleep problems, a prevalent one being night waking, can lead to fragmented sleep being a frequent occurrence. As a result, this reduced total sleep time can have detrimental effects relating to cognitive and social development, as well as poor emotional regulation and potential behavioural problems; links to maternal depression illustrate that the wellbeing of parents can also be impacted (Touchette, Petit, & Paquet, 2005). This review will explore the ‘normal’ sleep expectations in young children, as well as both the influence of parent and child characteristics. These characteristics can be important contributing factors to the occurrence of such sleep problems, and as such, a critical evaluation of the existing literature and research evidence will help provide a deeper understanding of these characteristics and the underlying influences behind them.

What constitutes ‘normal’ or adequate sleep in infants and young children is not particularly well defined in the extant literature (Dahl, 1998; Davis, Parker, & Montgomery, 2004). The total amount of sleep required for optimal functioning differs for each individual, therefore making it difficult to conclusively answer common questions raised by parents regarding how much sleep their child needs. Davis et al. (2004) provides several physiological measures that can be used to gain a general idea of what is considered ‘normal’ sleep. A child is sleeping adequately if they have the ability to fall asleep easily at night; this is stipulated as falling asleep in under 20 minutes. The other measures include being able to wake easily at their usual wake time (this ‘normal’ wake time will vary for each infant or child), as well as not displaying a need to nap during the day. Additionally, child sleep problems can also be defined in the context of parental expectations (Davis et al., 2004).

For instance, a sleep pattern involving a child sleeping early and waking early is not necessarily abnormal, but may be a problem for parents whose routines are disrupted. Thus, it is important to educate parents on what is ‘normal’ to prevent unrealistic expectations. One characteristic that persistent findings in the literature have found to be a crucial influence on the development of sleep problems in early childhood is parental involvement. These parental interactive behaviours, such as holding, rocking, or feeding their child can interfere with the infant or child’s development of the ability to self-soothe (Morrel & Cortina-Borja, 2002). Infants who fall asleep with significant parental involvement are more likely to experience longer and more frequent night wakings, due to a failure to adequately develop their own self-regulating and comforting abilities (Ferber, 1996). Children who experience continuous parental interventions over the course of the night learn to expect these conditions present at sleep onset, and often seek to re-establish these conditions, thus becoming reliant on these interactions to return to sleep after experiencing a night waking (Davis et al., 2004; Ferber, 1996). As such, minimal parental involvement during the settling process during the night can encourage more consolidated sleep. Additionally, parental presence in the form of co-sleeping or bed sharing has also been linked to poor infant and child sleep patterns (Mindell, Sadeh, Kohyama, & How, 2010), and hinders their independence (Owens, France, & Wiggs, 1999). However, many studies in this area have concentrated on Western cultures (Latz, Wolf, & Lozoff, 1999). These findings also provide multiple avenues for future research, for example, in determining the extent to which parental interaction is linked to sleep problems, as well as investigating the cultural differences in terms of parental behaviours and characteristics.

In exploring parental involvement and its effects on sleep consolidation in infants and young children, Touchette et al. (2005) conducted a longitudinal study that examined the factors most strongly associated with fragmented sleep in children, specifically at five, 17, and 29 months of age. Parental reports were used to identify the number of consecutive hours slept by the 1741 children who were part of these age groups. Feeding the child after awakening was the factor most associated with fragmented sleep at five months of age, while parental presence until sleep commencement was associated with the 17 and 29-month age groups. A key strength of this study was the amount of variables that were measured longitudinally in a large sample of children. However, there were also several limitations, one being that while the study pinpointed factors that covary with sleep consolidation in young children, it did not examine the underlying mechanisms behind those factors or the direction of the influence. Furthermore, the subjective nature of parental reports meant the number of hours slept consecutively may have included awakenings, with the possibility of the infant or child waking up briefly and going back to sleep without the parent being aware. However, Sekine et al. (2002) found a strong correlation between a parent’s approximation of the hours slept by their child and objective sleep laboratory data. As such, this study poses numerous avenues for future research, particularly in determining the extent to which parental interaction is linked to child sleep problems.

The transactional model also outlines the role of another characteristic, parent cognitions, which can impact sleep in infants and young children (Sadeh, Tikotzky, & Scher, 2010). Tikotzky and Shaashua (2012) explored the early predictors of sleep patterns in four year-old children in relation to the parental cognitions at 12 months. Findings revealed that maternal cognitions concentrated on the idea that infants experience distress when waking, and therefore require direct assistance, was associated with more frequent night wakings at months of age, and predicted higher parental involvement at four years. Conversely, maternal cognitions emphasising the importance of restricting night interaction predicted more consolidated sleep. Morrell (1999) also explored this cognition regarding difficulty in limit setting, as well as parents’ doubts about their competence and anger at their infant’s night-time demands. These findings provide some clinical implications, particularly in terms of parent education programs that address early parent cognitions and help prevent the development of sleep problems. Future research should also concentrate on using controlled studies to investigate the causal links between parent cognitions and children’s sleep, as a limitation of many previous studies has been that their studies have not permitted the inference for causal links (Tikotzky & Shaashua, 2012).

Infant insecurity is also an important characteristic, with a common statement reiterated in the literature being that infants who experience ambivalence in their attachment relationships are more likely to develop sleep problems (Sadeh et al. 2010). This relates to attachment theory (Ainsworth, 1973; Bowlby, 1969), as going to sleep can be a challenging, and potentially stressful task for many infants as it represents a separation from the ongoing interactions with their attachment figure. Morrell and Steele (2003) assessed attachment in 100 mothers and their 14 and 16-month old infants; 40 had sleeping problems, and 60 served as controls. With the use of a two-week sleep diary, it was found that there were a higher percentage of insecure-ambivalent infants in the group with sleep problems; this group also experienced more frequent and longer lasting night wakings. A follow-up study conducted at age two provided indications that the ambivalent group had a higher likelihood of sleep problems persisting later on. Moreover, the percentage of infants displaying ambivalent attachment and persistent sleep problems was slightly than those with concurrent sleep problems, suggesting ambivalent attachment poses a risk, although relatively small, to the development of sleep problems in early childhood. Despite this, the majority of infants with continuous sleep problems were securely attached to their mothers.

Therefore, while ambivalent attachment is a possible risk indicator for lasting sleep problems, factors such as active soothing, which Morrell and Steele (2003) state relates to the child’s temperament and parent’s cognition rather than attachment security, may be a better predictor. In conclusion, the existing literature has revealed that characteristics such as parent involvement and presence at night, parent cognitions, and infants’ attachment styles, can all have an influence on the development of sleep problems in early childhood. While many of these studies demonstrated strengths in being able to assess many different variables, a common limitation was an inability to determine or infer a causal link between these variables or examine the underlying factors behind these different influences. Furthermore, methodological problems in the literature were also identified; for example, the sole use of parent reports in many studies raises the issue of subjectivity. A gap in the literature was also identified, particularly in relation to investigating cultural differences in relation to these parent and child characteristics relating to sleep problems. As such, more research is needed to extend on the existing literature.