One in five children have experienced severe maltreatment, yet the long-term impact on mental and physical wellbeing is only just starting to be revealed.

Research by Dr Andrea Danese and colleagues at the Institute of Psychiatry, Psychology & Neuroscience (IoPPN) has shown that child maltreatment is associated not only with high risk for mental illness but also physical health problems like obesity.

'Childhood maltreatment, a severe and often prolonged psychosocial stressor, has traditionally been linked to psychiatric disorders. However, we are learning more and more that early-life stressors like maltreatment may also be linked to biological abnormalities and medical conditions later in life' says Dr Danese. 'We need to understand if the suggested links are causative or they arise artificially because of alternative mechanisms. We also need to understand if we can use information on biological abnormalities to identify maltreated children at greater health risk and to implement preventative interventions. The clinical and public health implications are substantial.'

This research has been cited by several national and international institutions - including the UK House of Commons, the National Society for the Prevention of Cruelty to Children (NSPCC), the World Health Organisation (WHO) and UNICEF - to highlight the significant health burden associated with childhood maltreatment, and to call for greater efforts to prevent maltreatment and to support children who were maltreated.

Prevention and early-intervention strategies are now viewed as cost-effective alternatives to later treatment of trauma-associated conditions in adults. Research by Dr Danese and colleagues was cited in a UK House of Common debate on the need for therapeutic services for abused children, which highlighted that 'expenditure in this area today saves substantially greater expenditure in the medium to longer term, and that, far from it being a cost, it is an investment in our children and our future'.

The research was mentioned in the WHO’s European report on preventing child maltreatment, which proposed 'a set of actions by EU Member States, international agencies, nongovernmental organisations and other stakeholders to address inadequate responses to child maltreatment’.This work was also referenced in UNICEF's first meeting on neuroscience at their headquarters in New York, which focused on why early childhood development is so important for individual and societal development, and how this science could influence UNICEF’s approach to achieve results for children.

It is also important to understand how maltreatment gets under children’s skin by looking at the health impact from a biological perspective. Research by Dr Danese and colleagues has shown that children exposed to traumatic stress, such as maltreatment, grow up to show high levels of immune molecules in their blood.

Maltreated children also show impaired response of the hormone leptin, which regulates appetite and other metabolic and immune functions. These molecular abnormalities, in turn, may help explain why maltreated children grow up to have high risk of several psychiatric and medical conditions. This work was cited in an NSPCC blog highlighting how knowledge about determinants of resilience and vulnerability in maltreated children could inform new tailored interventions.

Major scientific and funding bodies have cited these findings to highlight important advances in this area, to set future research directions, and to invite proof-of-principle trials targeting selected biological mechanisms. Dr Danese said: 'If we can understand how childhood maltreatment brings about ill health, if we can uncover the mechanisms through which early-life stress is translated into a biological risk for disease, then we will have new targets to stop the onset and progression of trauma-related disorders.'

References

• Agnew-Blais J, Danese A (2016) Childhood maltreatment and unfavourable clinical outcomes in bipolar disorder: a systematic review and meta-analysis. Lancet Psychiatry. 3(4):342-9
• Brenhouse HC & Andersen SL (2011) Nonsteroidal Anti-Inflammatory Treatment Prevents Delayed Effects of Early Life Stress in Rats. Biol Psychiatry. 70(5):434–40.
  
  
• Danese A, Pariante C, Caspi A, Taylor A, Poulton R (2007) Childhood maltreatment predicts adult inflammation in a life-course study. PNAS. 104(4):1319–24.
  
  
• Danese A, Moffitt TE, Pariante C, Ambler A, Poulton R, Caspi A (2008) Elevated inflammation levels in depressed adults with a history of childhood maltreatment. JAMA Psychiatry. 65(4):409–415.
  
  
• Danese A, Moffitt TE, Harrington HL, Milne B, Polanczyk G, Pariante C, Poulton R, Caspi A (2009) Adverse Childhood Experiences and Adult Risk Factors for Age-Related Disease: Depression, Inflammation and Clustering of Metabolic Risk Markers, JAMA Pediatrics. 163(12):1135–43.
  
  
• Danese A, Caspi A, Williams B, Ambler A, Sugden K, Mika J, Werts H, Freeman J, Pariante CM, Moffitt TE, Arseneault L (2011) Biological embedding of stress through inflammation processes in childhood. Mol Psychiatry. 16(3):244–6.
  
  
• Danese A & McEwen BS (2012) Adverse childhood experience, allostasis, allostatic load and age-related disease. Physiol Behav. 106(1):29–39.
  
  

• Danese A, Dove R, Belsky D, Henchy J, Williams B, Ambler A, Arseneault L (2014) Leptin deficiency in maltreated children, Transl Psychiatry.

• Danese A & Tan M (2014) Childhood maltreatment and obesity: systematic review and meta-analysis. Mol Psychiatry. 19(5):544–54.

• Danese A, Baldwin JR (2017) Hidden Wounds? Inflammatory Links Between Childhood Trauma and Psychopathology. Annu Rev Psychol. 68:517-544

• Nanni V, Uher R & Danese A (2012) Childhood Maltreatment Predicts Unfavorable Course of Illness and Treatment Outcome in Depression: A Meta-Analysis. Am J Psychiatry. 169(2):141–51.
• Raison CL, Rutherford RE, Woolwine BJ, Shuo C, Schettler P, Drake DF, Haroon E, Miller AH (2013) A Randomized Controlled Trial of the Tumor Necrosis Factor Antagonist Infliximab for Treatment –Resistant Depression: The Role of Baseline Inflammatory Biomarkers. JAMA Psychiatry. 70(1):31–41.