The study, which has been published in JAMA Network Open, is the largest study of its kind looking at the relationship between self-harm and bodily sensation, found that the threshold for sensitivity, both painful and not, increases significantly the more a participant had self-harmed in the past.
64 participants aged between 12-17 were recruited from a mixture of community and residential care settings, as well as schools and youth groups in London and Glasgow. Each individual underwent a series of 13 tests, including thermal detection and pain thresholds, and pressure pain thresholds to establish at what point they detected a change in sensation or first began to feel pain.
At no point were the participants asked to endure pain and were under strict instruction to stop the test the moment that they felt any sign of discomfort.
Suicide is the second highest cause of death among teenagers, and self-harm is the strongest predictor of suicide. The investigators now say that this has the clinical potential to be an effective test for identifying youths that are at the highest risk.
Dr Dennis Ougrin, the study's Co-Lead author from King's IoPPN, said "Rates of self-harm and suicide in children and adolescents have been rising in the UK, and we most commonly see the first episodes of self-harm take place around the age of 12.
"From the studies that we conducted, we can see that teenagers who have self-harmed five or more times in their past have a dramatically higher pain threshold, particularly in individuals that are living in care."
Young people in care constitute less than 1% of the UK under 18 population, yet account for about half the suicides. There is not yet have a reliable biomarker for suicide, but it is something that Dr Ougrin hopes can change.
"Once a person has become comfortable enough with pain, when they have raised the threshold far above what it would normally be in someone that hasn't self-harmed, it is at that point we can say that they are at greater risk of suicide."
The investigators now hope that these findings can be converted into a simple test using a pressure sensor to effectively identify at risk individuals so that they can be provided with targeted support.
Professor Stephen McMahon, the study's Co-Lead author King's IoPPN, said "We have been using these quantitative measures of sensory function in many different patient groups, and I am amazed at the magnitude of the effects seen in these young people who self-harm".
Professor Helen Minnis, Professor of Child and Adolescent Psychiatry at Glasgow University said, "I was delighted to be part of this exciting study, which couldn't have been completed without the strong support of Glasgow City Council Social Work and Chief Social Worker Susanne Millar"
Tatum Cummins, the study's joint first author from King's IoPPN said, "Surprisingly, these findings extended to non-painful stimuli. We saw a significant hyposensitivity to innocuous stimuli in the most frequent self-harm group compared to our community control participants with no self-harm.
"What we don't yet know is whether pain hyposensitivity is a pre-existing risk factor for self-harm, rather than a result of it. Our findings that youths in care have sensory abnormalities, regardless of whether or not they have self-harmed, is striking and will need further investigation."
INFORMATION:
King's IoPPN, in partnership with the South London and Maudsley NHS Foundation Trust and the Maudsley Charity, are in the process of opening a world leading centre for children and young people mental health. The Pears Maudsley Centre for Children and Young People is expected to open in 2023 and will bring together researchers and clinicians to help find solutions that will transform the landscape for children's mental health.
This study was possible thanks to funding from the Medical Research Council (UK) and the National Institute for Health Research (NIHR) Biomedical Research Centre.
For more information, please contact Patrick O'Brien, Senior Media Officer (Patrick.1.obrien@kcl.ac.uk)
Assessment of Somatosensory Function and Self-harm in Adolescents (doi:10.1001/jamanetworkopen.2021.16853) (Tatum M. Cummins, MSc; Oliver English, MSc; Helen Minnis, PhD; Daniel Stahl, PhD; Rory C. O'Connor, PhD; Kirsty Bannister, PhD; Stephen B. McMahon, PhD; Dennis Ougrin, PhD, MBBS) was published in JAMA Network Open
About King's College London
King's College London is one of the top 35 UK universities in the world and one of the top 10 in Europe (QS World University Rankings, 2020/21) and among the oldest in England. King's has more than 31,000 students (including more than 12,800 postgraduates) from some 150 countries worldwide, and some 8,500 staff.
King's has an outstanding reputation for world-class teaching and cutting-edge research. In the 2014 Research Excellence Framework (REF), eighty-four per cent of research at King's was deemed 'world-leading' or 'internationally excellent' (3* and 4*).
Since our foundation, King's students and staff have dedicated themselves in the service of society. King's will continue to focus on world-leading education, research and service, and will have an increasingly proactive role to play in a more interconnected, complex world. Visit our website to find out more about Vision 2029, King's strategic vision to take the university to the 200th anniversary of its founding.
World-changing ideas. Life-changing impact: https://www.kcl.ac.uk/news/headlines.aspx
About the University of Glasgow
Ranked in the top 100 of the world's universities, we deliver world-class and world-changing research and education with impact. We are a member of the prestigious Russell Group of leading UK Universities and are joint 1st in this group for student satisfaction. We are connected to seven Nobel Laureates, and 81% of our research is judged to be internationally excellent. Further information can be found here: http://www.gla.ac.uk/explore/
About the Medical Research Council
The Medical Research Council is at the forefront of scientific discovery to improve human health. Founded in 1913 to tackle tuberculosis, the MRC now invests taxpayers' money in some of the best medical research in the world across every area of health. Thirty-three MRC-funded researchers have won Nobel prizes in a wide range of disciplines, and MRC scientists have been behind such diverse discoveries as vitamins, the structure of DNA and the link between smoking and cancer, as well as achievements such as pioneering the use of randomised controlled trials, the invention of MRI scanning, and the development of a group of antibodies used in the making of some of the most successful drugs ever developed. Today, MRC-funded scientists tackle some of the greatest health problems facing humanity in the 21st century, from the rising tide of chronic diseases associated with ageing to the threats posed by rapidly mutating micro-organisms. The Medical Research Council is part of UK Research and Innovation. https://mrc.ukri.org/
