Many mental health problems affecting adults have their roots in childhood and adolescence. As we gain greater understanding of foetal and early infant development, and develop better assessments, it becomes clearer that even this very early period of life holds importance for later health and wellbeing – right through adult life.

However, for early intervention to work, effective interventions have to be available and, at present, the evidence for the effectiveness of early interventions that actually make a difference to mental health is extremely limited. There is evidence from randomised controlled trials that interventions such as the Nurse Family Partnership (NFP) and Video Feedback to Promote Positive Parenting (ViPP) can improve some outcomes (Juffer et al, 2007; Groeneveld et al, 2011), however the evidence for mental health outcomes is sparse.

In the UK, Parent Infant Psychotherapy (PIP) is strongly promoted as a solution for many difficulties in infancy and is recommended in an increasing number of policy documents, including the important Critical 1001 Days Manifesto (Leadsom et al, 2014). However, there have been few systematic attempts to critique the evidence for PIP.

This new Cochrane systematic review, conducted by Professor Jane Barlow and colleagues, is therefore timely and important (Barlow et al, 2015). It was conducted with the aim of assessing the effectiveness of PIP in relation to a range of primary outcomes; parent mental health, infant mental health (including attachment) and the parent-infant relationship.

Methods

A comprehensive search (electronic databases, reference lists, and contacting of study authors and other experts) was conducted for randomised controlled trials (RCT) and quasi-RCTs that:

• Compared PIP with a control treatment (waiting list, treatment as usual, or another treatment)
• Included parents with infants aged 24 months or less
• Used at least one standardised measure of parental or infant functioning

Meta-analyses were conducted for each of the primary outcomes (where data were available) and separately for PIP versus waiting list or treatment as usual and PIP versus another treatment. Results were reported as Relative Risk (RR) for dichotomous outcomes and Standardised Mean Difference (SMD) for continuous outcomes

Results

Eight studies including 846 participants were included, though smaller numbers were included for each of the separate primary outcomes as each study only reported on a subset of the primary outcomes of interest. The studies providing data for the meta-analysis were assessed by the authors as being of low or very low quality. For most of the primary outcomes there was no evidence of benefit of PIP over any of the control treatments.

• Parental depression Relative Risk (RR) 0.74 (95% Confidence Interval (CI) 0.52 to 1.04)
• Parent-child interaction (parental sensitivity) Standard Mean Difference (SMD) -0.13 (95% CI -0.64 to 0.38)
• Infant outcomes: attachment – secure attachment RR 8.93 (95% CI 1.25 to 63.70)
• Infant outcomes: externalising behaviour SMD 0.22 (95% CI -0.34 to 0.77)

There was a difference found for infant attachment status, but not other infant outcomes. Infants were more likely to be assessed as securely attached following PIP compared to control group.

Conclusions

The authors conclude that:

PIP is a promising model in terms of improving infant attachment security in high-risk families, there were no significant differences compared with no-treatment or treatment-as-usual for other parent-based or relationship-based outcomes, and no evidence that PIP is more effective than other methods of working with parents or infants.

Strengths and weaknesses

This is a well-conducted systematic review with clearly stated a priori outcomes of interest, as would be expected of a Cochrane review. The most significant weakness is the striking lack of high quality research evidence to support PIP as an effective intervention.

Comment

The key finding from this review is that the evidence for most of the a priori primary outcomes (child outcome, parental sensitivity, parental depression) shows no benefit of PIP. There is some evidence for a benefit on child attachment status when PIP is compared to no treatment, but the authors note that this finding is based on two studies which they rate as low or very low quality evidence. In addition the very wide confidence intervals (1.25 to 63.70) suggest the estimate of effect is not precise. There is no evidence of benefit of PIP over other treatment interventions (which included psychoeducational interventions and cognitive behaviour therapy).

Two key points struck me as I studied this review.

1. First, there are relatively few studies, and these are reported as providing weak or very weak evidence (i.e. either having important methodological limitations or being reported in a way that does not rule these out). This is a significant problem, particularly given that parents in over 800 families have consented for themselves and their infants to take part in research which the authors of this review conclude is weak and doesn’t help much with the planning of healthcare. There are apparently other studies underway, and it is crucial that these are robustly conducted to a high standard and with sufficient power. There is no excuse for further small, poorly conducted and reported trials, particularly when the health of infants is at stake. It should go without saying that the highest standards of research are an ethical prerequisite.
2. The second point is the contrast between the available evidence and the promotion of PIP as an “evidence-based treatment” for infant mental health problems. This mismatch strikes me as potentially problematic, particularly when there is evidence that other briefer treatments, such as ViPP, can be effective in improving outcomes such as sensitive parenting and infant attachment status. Parent Infant Psychotherapy (PIP) may have a role in the treatment of infant mental health problems and parenting difficulties, and future trials may help to elucidate that (the Cochrane review identifies 5 trials that are currently underway), but on the basis of the evidence in this Cochrane review, it’s role is far from clear.

Conflict of Interest Statement

The Cochrane review (Barlow et al, 2015) was funded by PIP-UK (a “Charitable organisation with a remit to establish parent-infant psychotherapy services across England”).

Paul Ramchandani receives funding from the National Institute of Health Research (NIHR) to develop and evaluate early interventions to promote infant mental health in early life, including a randomised controlled trial of ViPP for children at risk of behavioural problems.

Links

Barlow J, Bennett C, Midgley N, Larkin SK, Wei Y. (2015) Parent-infant psychotherapy for improving parental and infant mental health. Cochrane Database of Systematic Reviews 2015, Issue 1. Art. No.: CD010534. DOI: 10.1002/14651858.CD010534.pub2.

Juffer F, Bakermans-Kranenburg MJ, and Van IJzendoorn MH. (Eds) (2007) Promoting positive parenting: An attachment-based intervention. New York: Routledge.

Groeneveld MG, Vermeer HJ, van Ijzendoorn MH, Linting M. (2011) Enhancing home-based child care quality through video feedback intervention: randomized controlled trial. J Fam Psychol. 2011 Feb;25(1):86-96. doi: 10.1037/a0022451. [PubMed abstract]

Leadsom A, Field F, Barstow P, Lucas C. (2014) The 1001 Critical Days: The Importance of the Conception to Age Two Period. A cross-party manifesto (PDF). Wave Trust, 2014.