Why sleep train?
At some point during their child's infancy or childhood, many parents wonder whether there is something they could - even should - be doing to 'help' their baby sleep longer, deeper, better, or through the night. Health professionals are often asked to advise on sleep problems and sleep training.
Conceptualising what is meant by 'sleep problems' in infancy or childhood is fraught with difficulties. As with many other behavioural issues in childhood, identification of the existence of a problem, and its nature, often relies on parental report, rather than objective diagnostic criteria. Although specific diagnostic criteria for sleep problems in infants exist (e.g. ICSD-R 2001; ICSD-2 2005), the majority of research into methods for managing babies' sleep is based on parental identification of 'sleep problems' in their child. As it is parents who must cope with the effects of night waking or other sleep problems, this starting point makes sense, but it is important to note that parental perspectives are influenced by a wide variety of additional factors beyond that of their infants' sleep patterns per se. Such factors include parental education, physical and mental health, family structure and parenting style or ethos (Mindell et al 2006). For example, Hughes et al (2015) found that parents who perceive their infants’ sleep to be problematic, were more likely to experience stress or depressive symptoms and have poorer self-reported health. However, Hughes et al assert that infant sleep and maternal psychological health is bidirectional and mutually maintaining. As a result, is possible that parental mental health could influence reporting of more infant sleep problems. This study also suggests that cultural factors affect how parents manage and perceive their children’s sleep; parents of different ethnicities and cultural backgrounds but similar infant and adult sleep durations vary in reporting their child's sleep as a problem (Tsai et al 2014; Nishihara & Horiuchi 1998).
Sleep problem -- or parent-infant dissonance?
As a consequence, many of the programmes devised to improve babies' sleep are aimed at and/or tested on babies or children who -- by objective clinical or developmental measures -- are sleeping normally. The 'sleep problem' in these cases is the dissonance between how babies sleep and how parents want them to sleep. In most cases it is the signalling (crying) accompanying night waking that disturbs parents, rather than the waking itself, so many techniques focus on managing crying, rather than sleep (Blunden et al 2011). As the following evidence shows, it is certainly possible to influence infant sleep patterns and associated behaviours by manipulating sleep environments and interactions - however there is little to no research evidence evaluating the consequences of altering developmentally normal sleep patterns in infants and young children.
Sleep training methods
Behavioural interventions to 'improve' infant sleep have been implemented and researched over many years -- the first evaluation of the well-known "Cry It Out" method took place in 1959 (Mindell et al 2006). The normal development of sleep patterns in children (neurodevelopmental and circadian maturation) is influenced by both 'internal' (e.g. temperament, medical issues) and 'external' (environmental) factors (Mindell et al 2006). Behavioural 'sleep training' techniques are based broadly on modification of the latter, and tend to emphasise either reinforcement of desirable behaviour (e.g. positive routines), or avoidance of reinforcement of undesirable behaviour by parental ignoring (e.g. extinction).
Various reviews of 'sleep training' methods have been published (e.g. Kuhn & Weidinger 2000; Črnčec et al 2010). A recent review of the literature published since 1970 (Mindell et al 2006), plus a systematic review of studies published between 2000 and 2012 conducted by the Basis team, form the basis for the research evidence presented here. The published evidence has examined both well-known, and less-well-known, sleep training methods. These include:
Extinction - Unmodified (Cry it out)
Extinction - Graduated (Controlled crying)
Extinction - With parental presence (Cry it out with parent in the room / Camping out)
Positive Routines, Bedtime Routines, and Positive Reinforcement
In this summary we discuss above sleep training techniques when used with children who do not exhibit medical or psychiatric sleep-related conditions. We consider the evidence base, including the results of our own systematic review of the literature; limitations of the research conducted so far; and the potential risks associated with behavioural sleep management techniques.