The first 1000 days

04 October 2019

Jane Barlow says we need new sorts of evidence to enable CPs to play their role in equalising the life chances of all children and giving them the best start in life.

Poverty in the UK has increased over the past decade, with 4.1 million children estimated to be living in poverty in the UK in 2017-18 – that is 30% of children, or nine out of a classroom of 30 (Child Poverty Action Group, 2019). Poverty continues to be a significant predictor of poor nutritional, psychological and educational outcomes, with evidence of adverse effects as early as at two years of age (Black et al, 2000). This is possibly due, at least in part, to the impact of the chronic stress associated with poverty on the physiological functioning of the child –in particular the development of the brain (Shonkoff, 2016; Shonkoff et al, 2012). Community practitioners (CPs) who work with families during the first 1000 days, when significant neurological development is taking place, therefore have a key role to play in equalising the life chances of all children (Marmot et al, 2008).

What are the issues?

The evidence shows that when young children are exposed to the type of severe stress more common in families living in poverty – recurrent physical and/or emotional abuse, chronic neglect, parental substance misuse, domestic violence or severe mental health problems – it leads to changed brain architecture and reduced thresholds for stress (Shonkoff, 2016). Furthermore, these alterations continue throughout life, increasing the risk of stress-related disease and cognitive impairment, and thereby continuing the cycle of disadvantage. For example, a recent study showed that exposure to disadvantaged environments that include low income, low maternal education, unstable family structure and harsh parenting was associated with a reduced telomere length, which is a biological marker of chronic stress, by nine years of age (Mitchell et al, 2014).

We now know that both prenatal and postnatal stress can cause alterations in the function of the hypothalamic-pituitary-adrenal axis, which produces the hormone cortisol. We are also increasing our understanding about some of the pathways underlying the alterations in fetal and child brain neurodevelopment, following early exposure to stress. For example, prenatal maternal anxiety is associated with an altered functioning of the placenta, in a way that may allow more cortisol to pass from mother to fetus (Glover, 2010).

Many families who are exposed to poverty face a range of additional problems, including an increased risk of mental health problems, and intimate partner violence. These problems increase the likelihood of an infant being exposed to excessive stress as a result of the impact of such problems on the interaction, and the increased likelihood of the child being exposed to parenting that is ‘frightened and frightening’ (Lyons-Ruth et al, 1999).

Is the evidence good enough?

The rise of evidence-based healthcare over the past two decades has led to a proliferation of manualised programmes aimed at breaking the cycle of disadvantage by improving the socioemotional development and/or early language and learning of disadvantaged children. Recent summaries of this evidence include an update of the Healthy Child Programme (Asmussen and Brim, 2018), and the fifth edition of Health for all children (Emond, 2019). In addition, the Early Intervention Foundation undertook a review of 75 programmes and identified more than 30 that were aimed at improving parent-child interaction, which were either well evidenced or had some evidence of impact (Asmussen et al, 2016).

One of the consequences of this burgeoning body of evidence about ‘what works’ is that it presents a number of dilemmas: How is it possible to decide which of these many programmes should be commissioned and delivered? How is it possible for busy practitioners to be trained in and deliver manualised programmes? What about the families whose problems are not addressed by the programmes, or who do not benefit from such generic approaches (Embry and Biglan, 2008)?

What works for whom?

The reason for the absence of affect in some families is complex. For example, recent research suggests children may have a differential susceptibility to environmental input such as parenting. Studies of the effectiveness of video feedback programmes, such as Video Intervention to Promote Positive Parenting and Sensitive Discipline (VIPP-SD), have shown it was most effective for children classified as ‘temperamentally highly reactive’ (Van Zeijl et al, 2006).

CPs need researchers to begin focusing their attention on the type of factors that can influence whether a particular type of intervention will work with families facing diverse problems. This means a greater focus on what works for whom, under what circumstances, instead of the current focus on effectiveness per se. For example, one study that examined the context and mechanisms associated with better outcomes across a number of infant massage programmes found that infant massage was unlikely to show benefit when provided on a universal basis to mother-infant dyads without interactional difficulties. The study found it was also unlikely
to benefit – and might even be harmful – as a stand-alone intervention for mother-infant dyads in which there are serious problems with the interaction as a result of a low level of reflective functioning. This study suggested that infant massage can only benefit a highly focused sector of the population – disadvantaged women with depression and low levels of social support (Underdown et al, 2013). Much more evidence of this sort is now needed.

Evidence-based kernels

These issues strongly support the need for more evidence regarding the ‘kernels’ of programmes associated with effectiveness. For example, a recent review to identify the components in parenting programmes most strongly associated with improved outcomes for children with disruptive behaviour found that, of 26 parenting techniques, three in particular were associated with stronger programme effects: positive reinforcement, praise and the use of natural/logical consequences. Other techniques, such as relationship building and parental self-management, were associated with stronger effects, but only when delivered to children experiencing problems (treatment programmes) as opposed to population or high-risk groups (prevention programmes). This identification of ‘evidence-based kernels’ would provide CPs with the opportunity either to select programmes optimising delivery of such components, or to use them flexibly with families experiencing complex problems (Embry and Biglan, 2008).

To achieve the goals of the new Prevention Green Paper (Public Health England, 2019), we need a new sort of evidence that will give CPs the opportunity to acquire the skills associated with a wide range of evidence-based practices as part of their core and continuing development. Only this sort of evidence will enable them to meet the increasingly complex needs of parents with young children, and thereby to play a significant role in equalising the life chances of all children in the first 1000 days.  

Jane Barlow is professor of evidence-based intervention and policy evaluation at the University of Oxford, and president of the UK Association of Infant Mental Health. 


  • This seminal paper by Shonkoff (2012) published in Pediatrics, describes how early life adversity and toxic stress can have lifelong effects: bit.ly/Shonkoff_2012  
  • Read this two-year update of the State of child health in England, the 2017 version of which revealed alarming health inequalities between the UK’s most disadvantaged children and young people and their more affluent peers: bit.ly/RCPCH_study 

Time to reflect:

How would more information about the type of parents that different interventions work for help you to be more effective in practice? Share any insights and join the conversation on Twitter @CommPrac #first1000days


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Asmussen K, Feinstein L, Martin J, Chowdry H. (2016) Foundations for life: what works to support parent-child interaction in the early years? See: https://www.eif.org.uk/report/foundations-for-life-what-works-to-support... (accessed 9 September 2019).

Black M, Hess CR, Berenson-Howard J. (2000) Toddlers from low-income families have below normal mental, motor, and behavior scores on the revised Bayley scales. Journal of Applied Developmental Psychology 21(6): 655-6. 

Child Poverty Action Group. (2019) Child poverty facts and figures. See: cpag.org.uk/child-poverty/child-poverty-facts-and-figures#footnote1_zygpg31 (accessed 9 September 2019). 

Embry DD, Biglan A. (2008) Evidence-based kernels: fundamental units of behavioural influence. Clinical Child And Family Psychology Review 11(3): 75-113. 

Emond A (ed). (2019) Health for all children (fifth edition). OUP: Oxford.

Glover V, O'Connor TG, O'Donnell K. (2010) Prenatal stress and the programming of the HPA axis. Neuroscience and Biobehavioural Review 35(1):17 22. 

Lyons-Ruth K, Bronfman E, Parsons E. (1999) Maternal frightened, frightening, or atypical behavior and disorganized infant attachment patterns. Monographs of the Society for Research in Child Development 64(3): 67-96. 

Marmot M , Friel S , Bell R , Houweling TA, Taylor S. (2008) Closing the gap in a generation: health equity through action on the social determinants of health. The Lancet 372 (9650): 1661-9. 

Mitchell C, Hobcraft J, McLanahan SS, Siegel SR, Berg A, Brooks-Gunn J, Garfinkel I, Notterman D. (2014) Social disadvantage, genetic sensitivity, and children's telomere length. Proceedings of the National Academy of Science of the United States of America 111(16): 5944-9. 

Public Health England. (2019) The Prevention Green Paper: a chance to turn talk into action. See: https://publichealthmatters.blog.gov.uk/2019/07/23/the-prevention-green-... (accessed 9 September 2019).

Shonkoff JP. (2016) Capitalizing on advances in science to reduce the health consequences of early childhood adversity. JAMA Pediatrics 170(10):1003-7. 

Shonkoff JP, Garner AS. (2012) The lifelong effects of early childhood adversity and toxic stress. Pediatrics 129(1): e20162595. 

Underdown A, Norwood R, Barlow J. (2013) A realist evaluation of the processes and outcomes of infant massage programs. Infant Mental Health Journal 34(6): 483-95.  

Van Zeijl J, Mesman J, Van IJzendoorn MH, Bakermans-Kranenburg MJ, Juffer F, Stolk MN, Koot HM, Alink LR. (2006) Attachment-based intervention for enhancing sensitive discipline in mothers of 1- to 3-year-old children at risk for externalizing behavior problems: a randomized controlled trial. Journal of Consulting and Clinical Psychology 74(6): 994-1005.