This analysis was submitted to Sleep Health in 2023. It demonstrates the key elements of the Neuroprotective Developmental Care Contextual Model of Infant Sleep (NDC-MIS), published by Whittingham & Douglas 2014. Sleep Health published an abridged version of this table in:

Douglas PS. The need to acknowledge similarities between the 2022 D'Souza and Cassels and the 2014 Whittingham and Douglas contextual models of infant sleep. Sleep Health. 2023;9:797-800.

Analysis of existing approaches and theoretical frameworks for parent-infant sleep

Prior development of contextual theoretical foundations of Neuroprotective Developmental Care Model of Infant Sleep (NDC-MIS) in four publications including:

• Stakeholder engagement in development of theoretical frame

• Systematic review of existing infant sleep research, theoretical models, and clinical/educational translations.3-6

Identification of existing infant sleep models

Two prior existing infant sleep models identified, the dominant behavioural model, and the ecological model, referred to as an ‘alternative paradigm: normalizing night-waking’.

A. The ecological model of parent-infant sleep

‘Multiple researchers and health professionals … have suggested an alternative paradigm in which infant night-waking is normalized. We draw on their important work concerning normal parent-infant sleep ecology.’ This theoretical base is described as ‘evolutionary anthropology’.

Clinical/educational implications of this model are also detailed in second column Table 1 of 2014 article, including education about developmentally normal night-waking and irregular daytime sleep; ‘parents are advised to sleep baby in same room day and night …. to respond to their baby’s cues … to sleep baby near enough to exchange sensory cues day and night, and to sleep in an environment with normal light and noise during daytime naps.’

B. Behavioural model of parent-infant sleep

Behavioural model and its clinical/educational translations ‘aim to increase duration of the infant’s nocturnal self-regulated sleep’. ‘The dominant paradigm trains infants to settle to sleep in a manner that does not require parental presence’.

C. Transactional model

Transactional model not named but early transactional models of bidirectional interplay between culture and biology are cited (Jenni and Carskadon 2005;2007), with observation that ‘sleep behavior must be viewed within a biopsychosocial framework’

Critique of existing infant sleep models

• ‘The benefits of flexible, cued care are increasingly well-documented’

• ‘Exclusively breast-feeding mothers have improved quality and duration of sleep’

• ‘Behavioral sleep interventions risk unintended outcomes, including … worsened maternal anxiety’

• ‘Parents make sense of their baby’s cues through a continual process of flexible parent-infant experimentation, which facilitates stabilization of the complex, adaptive parent-baby system through multiple behavioral and neurohoronal feedback loops. Further, cued care promotes parental flexibility and enjoyment… (e.g. affection, acting in accordance with values).’

Identified gap in existing models

‘The Possums approach is clearly distinct from the dominant paradigm as well as from the existing alternative paradigm of education and normalization.’

NDC-MIS and the Possums Sleep Program is developed from the understanding that families’ values (cultural or personal) and parenting styles shape behaviour, which may cause or maintain differences in infant sleep quality. Explores how this can be addressed by inviting experimentation in ways that are sensitive to context.

Proposed new theoretical model of parent-infant sleep

‘We understand sleep contextually.’ NDC MIS is ‘interdisciplinary. It integrates contemporary contextual behavioral science (including operant theory), complexity science, evolutionary anthropology, neuroscience, clinical lactation science, developmental theory.’

Strategies from contextual behavioural science support parents’ capacity to experiment with new values-aligned behaviours. ‘We situation infant sleep within the wider context of the parent-infant relationship, and we understand sleeping patterns, sleep needs, and sleeping problems as emerging out of this complex and dynamic system. The parent-infant relationship is located in the broader systems of family, society and culture.’ ‘For this reason, we maintain that an infant’s sleep patterns cannot be understood without also understanding the full complexity of the parent-infant relationship, including feeding patterns, patterns of sensory stimulation and physical contact, and philosophies of care.’ ‘Parent-infant sleep is a complex adaptive system.’ ‘Parents make sense of their baby’s cues through a continual process of experimentation and pattern recognition, taking into account wider context.’

Takes parental cultural beliefs, norms, and values as a starting point and overarching context for examining perceived or presenting infant sleep problems. Aims to support parents if they wish to modify their contexts and behaviours in relation to the infant, in order to address the family’s sleep distress. Integrates contextual behavioural science strategies which are guided by the individual or family’s unique values, beliefs, and norms.7 Discusses how infant factors, parental emotional and mental well-being, parent-infant interactions and the environment interact and influence each other, and how these impact on parent and infant sleep-related behaviour.

How elements of the proposed new model translate into clinical or educational interventions

Overview from Possums Sleep Program (2015-2016), The Possums Baby and Toddler Sleep Program (2020), and Sleep Baby and You (2020) 1 8-10

Infant

• Provides biologically normal sleep education

• Addresses underlying infant health issues

Parent responsiveness to infant communications or cues

• Parental emotional availability and physical contact in the evenings and during the night

• Supports risk minimisation in proximal sleeping

• Supports responsive night-time interactions

Parent emotional well-being, occupational fatigue and mental health

• Education about sleep hygiene, derived from evidence-based Cognitive Behavioural Therapy for adult sleep problems

• Supports parent relationships (within the NDC domain of parent emotional well-being and mental health)

• Supports the adaptation to parenthood (within the NDC domain of parent emotional well-being and mental health)

• Identifies and treats underlying mental health problems

Support healthy function of the biological sleep regulators

• Examine infant morning wake time, day-time naps, bed-time, and pattern of night-time waking

• Daylight exposure to promote healthy circadian rhythm

• Rich daytime sensory nourishment

The infant

A. Exclude underlying medical conditions

The Possums sleep program is one domain of the NDC programs, which teach clinicians and educate parents to exclude underlying medical conditions which may impact on sleep or manage them as required. At the same time, infant behaviours are understood contextually and inappropriate medicalisation through application of the (dominant) reductionist lens is avoided.5 11-14

B. Educate family about biologically normal infant sleep

Provides evidence-based information about an infants’ environment of evolutionary adaptedness and evolutionarily normal behaviour such as frequent night-waking, breastfeeding to sleep, physical contact during sleep (educating about risk minimisation in bedsharing) and night-time responsiveness to infant communications. Invites experimentation and flexibility, respecting parents’ choices and unique values at all times. Uses the metaphor of the dial on the sympathetic nervous system to discuss infant behaviour. Does not label an infant’s temperament, which may have detrimental developmental impacts, but supports parental behaviours of experimentation in response to infant communications.

C. Address feeding issues

‘Infant sleep patterns are innately connected to other prominent neurobehaviors relevant to mother-infant synchrony, namely, feeding and sensory stimulation.’ ‘Postprandial somnolence is innate neurobehavior resulting from the effects of parasympathetic nervous system activation, elevated oxytocin, and elevated plasma cholecystokinin.’ Supports breastfeeding as an easy way to return the infant to sleep. Interacts with the NDC Breastfeeding Domain, in which underlying breastfeeding problems are identified and managed or referred to an appropriate provider. A range of breastfeeding problems which may become apparent during an infant sleep consultation are identified and managed or referred as appropriate, including difficulties with latching (fit and hold), and parent concerns about oral connective tissue restrictions, allergies and food intolerances. The positive effect of the Possums sleep program on breastfeeding outcomes has been demonstrated in a randomised controlled trial.15

Sleep-wake cycles may be affected by hunger-satiety problems in the first weeks and months of an infant’s life. Explains to parents that it is not possible to determine whether an older infant is cueing for a breastfeed or for physical closeness in the night, and that there is no benefit in withholding the breast, for as long as a mother wishes to breastfeed.

**Support parent responsiveness to infant communications **

Provides evidence-based knowledge of biological behaviours such as frequent night-waking, breastfeeding to sleep, close contact during sleep (risk minimisation in co-sleeping or bedsharing) and night-time responsiveness to infant cues. Parents are invited to experiment with behaviours which downregulate their own and the infant’s sympathetic nervous system.

Parent well-being

Contextual behavioural science strategies support ‘parental empowerment and flexibility (meta-cognition and behavior) to improve … vital living.’ ‘Cued care … is a process of flexible parent-infant experimentation, which facilitates stabilization of the complex, adaptive parent-baby system through multiple behavioral and neurohormonal feedback loops.’ ‘Direct targeting of elevated sympathetic nervous system arousal to improve maternal sleep efficiency.’ ‘Our aim is … to support the healthful biological regulation of sleep for both infant and parent as well as to optimize the parent’s sleep efficiency and resilience. We adapt practical, evidence-based strategies from the adult sleep intervention literature [sleep hygiene].’

Support healthy function of the biological sleep regulators

‘Two biological processes dominate the regulation of sleep: the homeostatic sleep factor and the endogenous circadian pacemaker.’

‘Parents are taught about two biological sleep regulators and their potential for misalignment.’ ‘The Possums Sleep Intervention includes education on the biological regulation of sleep via the circadian pacemaker and the homeostatic regulator …. as well as on lifestyle factors known to support healthful sleep regulation.’

‘Infant relaxation is best promoted through cued care and a rich sensory diet.’

‘Parents are taught to sleep baby near enough to exchange sensory cues day and night, and to sleep in an environment with normal light and noise during daytime naps; encouraged to lead an active and rewarding lifestyle accompanied by the baby, to optimize rich and healthy sensory diet.’

‘We do not problematise stimulation.’

‘Parents are taught techniques drawn from ACT’. That is, parents encouraged to allow their values (personal, cultural) to guide behaviours and choices; personal empowerment through experimentation and flexibility. Proposing changes to broader environmental and socio-structural factors is beyond the capacity of an educational or clinical intervention. Whilst acknowledged as context in the NDC MIS, an effective and sensitive clinical intervention cannot aim to change socioeconomic status, education level, minority status, poverty and crowded housing.

Implications for research

Because so many cultural and environmental factors interact and dynamically co-evolve with parent-infant sleep in this holistic model, a reductionist approach to research (attempting to isolate ‘single lines’) is unlikely to yield useful outcomes. Simplistic interventions applied to complex systems are known to risk in unintended outcomes. Methodologies appropriate for evaluation of a complex intervention such as the Possums Baby and Toddler Sleep Program is required, typically layering various methodologies in different studies. Offers a culturally inclusive lens.15-18, 10

References

1. Whittingham K, Douglas PS. Optimising parent-infant sleep from birth to 6 months: a new paradigm. Infant Mental Health Journal 2014;35:614-23.
2. D'Souza L, Cassels T. Contextual considerations in infant sleep: offering alternative interventions to families. Sleep Health 2022:S2352-7218(22)00077-8. doi: 10.1016/j.sleh.2022.05.006.
3. Douglas P, Mares R, Hill P. Interdisciplinary perspectives on the management of the unsettled baby: key strategies for improved outcomes. Australian Journal of Primary Health 2012;18:332-38.
4. Douglas PS, Hill PS, Brodribb W. The unsettled baby: how complexity science helps. Arch Dis Child 2011;96:793-97.
5. Douglas PS, Hill PS. A neurobiological model for cry-fuss problems in the first three to four months of life. Med Hypotheses 2013;81:816-22.
6. Douglas P, Hill PS. Behavioural sleep interventions in the first six months of life do not improve outcomes for mothers or infants: a systematic review. J Dev Behav Pediatr 2013;34:497–507.
7. Whittingham K, Douglas PS. "Possums": building contextual behavioural science into an innovative evidence-based approach to parenting support in early life. In: Kirkaldy B, ed. Psychotherapy in parenthood and beyond. Turin, Italy: Edizioni Minerva Medica 2016:43-56.
8. Douglas PS. The Possums Sleep Program: supporting easy, healthy parent-infant sleep. International Journal of Birth and Parent Education 2018;6(1):13-16.
9. Crawford E, Whittingham K, Pallett E, et al. An evaluation of Neuroprotective Developmental Care (NDC/Possums Programs) in the first 12 months of life. Maternal and Child Health Journal 2022;26(1):110-23.
10. Ball H, Douglas PS, Whittingham K, et al. The Possums Infant Sleep Program: parents' perspectives on a novel parent-infant sleep intervention in Australia. Sleep Health 2018;4(6):519-26.
11. Douglas PS. Re: Managing infants who cry excessively in the first few months of life. BMJ 2012:http://www.bmj.com/content/343/bmj.d7772/rapid-responses.
12. Douglas P. Diagnosing gastro-oesophageal reflux disease or lactose intolerance in babies who cry alot in the first few months overlooks feeding problems. J Paediatr Child Health 2013;49(4):e252-e56.
13. Douglas PS. Excessive crying and gastro-oesophageal reflux disease in infants: misalignment of biology and culture. Med Hypotheses 2005;64:887-98.
14. Douglas PS, Hill PS. The crying baby: what approach? Curr Opin Pediatr 2011;23:523-29.
15. Ozturk M, Boran P, Ersu R, et al. Possums-based parental education for infant sleep: cued care resulting in sustained breastfeeding. European Journal of Pediatrics 2021;180:1769-76.
16. Ball H, Taylor CE, Thomas V, et al. Development and evaluation of ‘Sleep, Baby & You’ - an approach to supporting parental well-being and responsive infant caregiving. Plos One 2020;15(8): e0237240.
17. Whittingham K, Palmer C, Douglas PS, et al. Evaluating the 'Possums' health professional training in parent-infant sleep. Infant Mental Health Journal 2020;41(5):603-13.
18. Closson L, Flykt M, Bringen Z. Evaluation of possums sleep intervention: a pilot feasibility study. Journal of Nursing Education and Practice. 2020;10(2):https://doi.org/10.5430/jnep.v5410n5432p5415.