Childhood trauma gets under the skin

Long-term changes in immune function caused by childhood trauma could explain increased vulnerability to a range of health problems in later life, according to new research by the Institute of Psychiatry, Psychology & Neuroscience (IoPPN) at King's College London and the NIHR Maudsley BRC.

The study, published today in Molecular Psychiatry, found heightened inflammation across three blood biomarkers in adults who had been victims of childhood trauma. High levels of inflammation can lead to serious and potentially life-threatening conditions such as type-2 diabetes, cardiovascular disease as well as the onset of psychiatric disorders.

Childhood trauma was defined by the researchers as experiencing sexual, physical or emotional abuse, neglect, or separation from caregivers before the age of 17. Previous research has shown that childhood trauma increases vulnerability to several psychiatric disorders, including depression, anxiety, psychosis and post-traumatic stress disorder (PTSD), as well as several chronic physical health problems, including arthritis, cardiovascular disease, lung disease and cancer. However, the biological pathway mediating vulnerability for these health problems has, until now, been unclear.

The researchers conducted a meta-analysis of 25 studies which previously investigated the association between childhood traumatic experiences and markers of inflammation in adulthood. The final sample comprised more than 16,000 people, including healthy participants and patients with psychiatric disorders or physical illnesses.

As well as the association between childhood trauma and increased blood inflammation, the researchers found that different types of trauma - emotional, physical or sexual abuse - affected these biomarkers in different ways. For instance, physical and sexual abuse was associated with significantly increased levels of two biomarkers - tumour necrosis factor-α (TNF-α) and interleukin-6 (IL-6), whereas heightened levels of c-reactive protein (CRP) appeared to be primarily related to parental absence during early child development.

Dr Valeria Mondelli from the Department of Psychological Medicine at the IoPPN, said: 'Our findings are important not only because they help us to understand more about why people with a history of childhood trauma may develop psychiatric disorders or physical problems in adulthood, but also because they open the possibility of prevention and treatment strategies for these individuals. For instance, using these inflammatory markers might make it possible to identify victims of childhood trauma who are at higher risk of developing physical or mental health problems, and to test potential treatments which could decrease inflammation in these individuals.'

Dr Mondelli added: 'We also found that different types of trauma are associated with different types of inflammation. While there is no clear reason for this, there are several factors which may offer some insight, including the age and length of exposure to childhood trauma and the victim's relationship with the perpetrator. However, further research into this and the molecular mechanisms behind these associations is warranted.'

She concluded: 'Understanding the biological consequences of childhood trauma may be crucial for identifying why some individuals go on to develop physical or psychiatric disorders following these traumatic experiences, whereas other remain resilient in face of similar traumatic exposure.'

###

This research was funded by the Medical Research Council with support from the National Institute for Health Research Biomedical Research Centre at South London and Maudsley NHS Foundation Trust and King's College London.

For further media information please contact Jack Stonebridge, Press Officer, Institute of Psychiatry, Psychology & Neuroscience, King's College London jack.stonebridge@kcl.ac.uk/ (+44) 020 7848 5377

King's College London is one of the top 20 universities in the world (2014/15 QS World University Rankings) and among the oldest in England. King's has more than 26,500 students (of whom nearly 10,400 are graduate students) from some 150 countries worldwide, and nearly 6,900 staff. The university is in the second phase of a £1 billion redevelopment programme which is transforming its estate.

King's has an outstanding reputation for world-class teaching and cutting-edge research. In the 2014 Research Excellence Framework (REF) King's was ranked 6th nationally in the 'power' ranking, which takes into account both the quality and quantity of research activity, and 7th for quality according to Times Higher Education rankings. Eighty-four per cent of research at King's was deemed 'world-leading' or 'internationally excellent' (3* and 4*). The university is in the top seven UK universities for research earnings and has an overall annual income of more than £600 million.

King's has a particularly distinguished reputation in the humanities, law, the sciences (including a wide range of health areas such as psychiatry, medicine, nursing and dentistry) and social sciences including international affairs. It has played a major role in many of the advances that have shaped modern life, such as the discovery of the structure of DNA and research that led to the development of radio, television, mobile phones and radar.

King's College London and Guy's and St Thomas', King's College Hospital and South London and Maudsley NHS Foundation Trusts are part of King's Health Partners. King's Health Partners Academic Health Sciences Centre (AHSC) is a pioneering global collaboration between one of the world's leading research-led universities and three of London's most successful NHS Foundation Trusts, including leading teaching hospitals and comprehensive mental health services. For more information, visit: http://www.kingshealthpartners.org.

King's fundraising campaign - World questions|King's answers - created to address some of the most pressing challenges facing humanity has reached its £500 million target 18 months ahead of schedule. The university is now aiming to build on this success and raise a further £100 million by the end of 2015, to fund vital research, deliver innovative new treatments and to support scholarships. The campaign's five priority areas are neuroscience and mental health, leadership and society, cancer, global power and children's health. More information about the campaign is available at http://www.kcl.ac.uk/kingsanswers.