Why The Period of PURPLE Crying program doesn't improve outcomes and may even worsen family distress: analysis of the evidence+ F2F Masterclass Melbourne 2018

Why The Period of PURPLE Crying program directly conflicts with the NDC or Possums 5-domain approach to Infant Cry-fuss Problems

The Period of PURPLE Crying has been developed over many years by the prominent Canadian paediatrician and crying baby researcher Professor Ronald Barr and his team, and has attracted substantial funding and government support. It's uptake has spread internationally. I propose that this is because The Period of PURPLE Crying program, with its predominant focus on a strategy hypothesised to prevent Shaken Baby Syndrome, fits the One Factor Fallacy, which is attractive to funders.

The Period of PURPLE Crying program is developed from an underlying theoretical model of infant crying, the developmental model, which proposes that infant crying for long durations in the first months of life is developmentally normal. (Please visit here to see my table of the various explanatory models for infant cry-fuss behaviour currently in use internationally.) It is developed in response to the finding that infants who cry excessively in the first months of life are more likely to present with Abusive Head Trauma.

The Period of PURPLE Crying builds on the hypothesis that education about the normality of problem infant crying in the first months of life, and the recommendation that the parent put the crying baby down in a safe place and walk away when the parent is feeling overwhelmed by strong emotions, will decrease rates of Shaken Baby Syndrome.

The developmental model of infant crying conflicts with the NDC neurobiological model of infant crying, which argues from the research that crying initiation occurs at a similar rate across culture in first few months of life, but crying durations are demonstrated to vary with different cultural infantcare practices. The NDC neurobiological model hypothesises that if clinical support is able to decrease crying durations, and support parent mental health and psychological resilience, then rates of Abusive Head Trauma will also reduce, and mental and emotional wellbeing will improve.

• The developmental model of infant crying is clinically translated into The Period of PURPLE Crying program. This educational and clinical translation is concerned to normalise excessive infant crying in the first few months of life, at the same time as it recommends parent coping strategies, in particular placing infant in safe place and leaving the room. This approach is hypothesised to avoid Shaken Baby Syndrome.

• The neurobiological model of infant crying is clinically translated into The NDC or Possums 5-domain approach to infant cry-fuss problems. This educational and clinical translation is concerned to address multiple interacting clinical problems which result in long crying durations and frequent bouts of inconsoleable crying in the first few months of life, including strategies which support parent emotional and mental wellbeing. This approach is hypothesised to decrease crying durations, decrease rates of Abusive Head Trauma, and improve parent mental health and wellbeing.

What other concerns are raised by an analysis of The Period of PURPLE Crying program through the NDC lens?

Other important concerns are that The Period of PURPLE Crying program

• Has not been shown to help babies cry less

• Has first wave behavioural strategies for infant sleep encorporated into it

• Does not integrate the science of clinical breastfeeding support and how clinical breastfeeding problems impact upon infant crying

• Has not been shown to improve parent mental health

• Commences its acronym of PURPLE with a 'P' for peak crying, but the evidence does not particularly support the existence of a crying peak (Vermillet et al 2022; Wolke et al 2017)

• May raise awareness about Shaken Baby Syndrome and the importance of putting the crying baby down in a safe place and walking away if a parent feels overwhelmed by strong negative emotions, but

• This piece of education, even if it were to be effective in preventing Shaken Baby Syndrome, does not require the rest of The Period of PURPLE Crying program, which conflicts with the NDC approach

• May, when promoted as a public health measure, undermine parental confidence in their capacity to manage difficult thoughts and feelings while baby is crying, that is, may worsen cognitive fusion with distressed thoughts and feelings

• May, when promoted as a public health measure, support cognitive fusion with thoughts of harming baby, which are very common in new mothers but very rarely associated with actual harm behaviours, exacerbating parent anxiety and distress and worsening mental health outcomes. You can find out more here.

What do evaluations of The Period of PURPLE Crying program show?

1. A 2022 systematic review and meta-analysis by Scott et al which investigates the efficacy of educational programs (predominantly The Period of PURPLE Crying) for prevention of Abusive Head Trauma (AHT) in infants finds that

   • Preventative educational intervention result in marginal improvements only in parental response to inconsolable crying

   • Weak evidence only that the intervention increased parental behaviour of walking away from crying infants.

   Scott et al conclude:

   Low certainty evidence suggests that educational programmes for Abusive Head Trauma prevention are not effective in preventing AHT. There is low to moderate certainty evidence that educational interventions have no effect or only marginally improve some parental responses to infant crying.

2. A 2024 systematic review and meta-analysis by Chang et al (in which eight of 18 selected studies were evaluations of The Period of PURPLE Crying; the other ten evaluations were of a total of eight other programs) found no change in the incidence of Abusive Head Trauma or improved parental emotional self-regulation.

4 June 2024

Selected references

Chang H-Y, Chang Y-C, Chang Y-T. The effectiveness of parenting programs in preventing abusive head trauma: a systematic review and meta-analysis. Trauma, Violence, & Abuse. 2024;25:354-368.

Scott LJ, Wilson R, Davies P. Educational interventions to prevent paediatric abusive head trauma in babies younger than one year old: a systematic review and meta-analyses. Child Abuse & Neglect. 2022;134:105935.

Vermillet A-Q, Tolboll K, Mizan SL, Skewes JC, Parsons CE. Crying in the first 12 months of life: a systematic review and meta-analysis of cross-country parent-reported data and modeling of the "cry curve". Child Development. 2022.

Wolke D, Bilgin A, Samara M. Systematic review and meta-analysis: fussing and crying durations and prevalence of colic in infants. Journal of Pedatrics. 2017;185:55-61.