Poor evidence around ‘toxic trio’ poses questions for child protection

Research led by the National Children's Bureau and the Universities of Cambridge and Kent finds little evidence to support the focus in child social work on the combined effect of the so-called 'toxic trio'.

The toxic trio - parental mental illness, drug or alcohol misuse, and domestic violence – are known to be significant, individual indicators of children being in danger of harm or abuse. However, a prevalent belief, in social work and beyond, is that when these factors occur in combination the risks to children multiply significantly.  

But a systematic review of existing research, published in the Children and Youth Services Review, suggests there is very little understanding of how, and indeed if, they combine to significantly increase the danger to children.


The research shows that the limited number of studies that consider the three factors in combination lacked the precision, detail and depth needed to inform good policymaking, or even to estimate how common these factors are or how many children are experiencing abuse and neglect as a result of them.

Researchers also found that existing studies lacked consistency in how the toxic trio were defined – for example by sometimes including learning disability within the scope of mental illness. Similarly, existing research often overlooked whether families were able to access services to help with their problems, or how the trio of factors affects children of different ages or identities, with different backgrounds or socioeconomic conditions, such as living in poverty.


Researchers consulted parents on their findings, who described feelings of being unfairly questioned and judged in some of their interactions with social care. They found the concept of the toxic trio ‘offensive and alienating’ and believed a preoccupation with it could have played a role in their negative experiences.

The article calls for the children’s sector to unlearn the assumptions lying behind the toxic trio, to rethink the purpose and direction of child protection and to build a well-constructed evidence base to inform policy, service provision and practice.

Anna Feuchtwang, Chief Executive of the National Children’s Bureau, said:

“Parental mental ill-health, domestic violence, and drug or alcohol misuse, are undoubtedly significant risk factors in children’s lives. But so are other factors, such as families' financial resources and the support available to them within their communities. Labels like “toxic trio” can lead to making assumptions that are not borne out by the evidence and this risks alienating families rather than supporting children. It’s essential that social workers are given the right tools to make an evidence informed approach to prevent harm.  We look forward to the Living Assessments programme looking carefully at unanswered questions which will lead to better support for children and their families.

The research is part of the Living Assessments programme which explores what is considered in social care assessments of children in need in England, including those who are disabled. It is made possible by a five-year investment by Wellcome in a collaboration between University of Cambridge, University of Kent and the National Children’s Bureau in conjunction with the All-Party Parliamentary Group for Children and the British Association of Social Workers.