Study assesses link between early adversity and self-harm

Most research on self-harm focuses on psychological risk factors, but we have little information on biological factors that might increase the chances that young people may self-harm.

This is an area myself and colleagues are researching. Research over the past 30 years has shown that facing bad or adverse experiences early in life - such as abuse or neglect, having parents with criminal convictions or witnessing domestic violence - leads to people being at a higher risk of self-harm or attempting to end their life. We don't yet understand why this happens.

Early experiences can impact on the way the body works - changing hormones, influencing chemicals around genes and activating the immune system, for example. The effect of these on the body might increase the risk of self-harm - for example, by changing the levels of neurotransmitters in the brain that impact on mood.

The main aim of our project was to explore whether inflammation, or how activated a young person's immune system is, explained the link between childhood adversity and later self-harm in the cohort of young people in the Bristol Children of the '90s study.

We looked at nine types of adversity and found that the more adverse experiences a young person had before the age of nine, the more likely they were to report they had self-harmed by the age of 16. Specifically, for every extra type of adversity, a young person was on average 11 per cent more likely to report self-harm and 22 per cent more likely to report self-harm with suicidal intent.

We also measured how active children's immune systems were by taking a blood sample when they were nine-and-a-half and measuring the levels of two markers of inflammation, but we did not find any evidence of a link going from adversities through inflammation to self-harm. This means activation of the immune system in children is not likely to be a useful indicator of whether they may self-harm later.

Greater risk

Young people who experience adversity are at a higher risk of self-harm. However, it is important to be aware that many people have adverse childhood experiences (ACE): in our study only one-third of young people had none of the adversities we measured.

This means it will be difficult for health and social care practitioners to accurately identify young people at risk based on their ACEs, but those with a high burden of early adversity are at the highest risk of self-harm and suicide attempt.

As one in four young people self-harm, ensuring that they can access mental health services locally is important in order to support them to develop alternative coping strategies.

The potential of using measures of ACEs to target treatment or as a screening tool has been criticised. Preventing ACEs from occurring at all is perhaps unfeasible and a major undertaking that will require joined up working by a wide range of service providers.

As with many factors, adversities occur in intergenerational cycles, and some of the negative outcomes associated with adversity increase the likelihood of the next generation experiencing it.

Bristol is one area that has begun to tackle this challenge. There, the council, NHS, police and voluntary sector partners are collaborating as part of the "One City" initiative by the City Office. There are ambitions to make Bristol an "ACE Aware City", training public service staff by 2020 and having all parents aware of the future impact of ACEs on health and wellbeing by 2025.

These efforts are laudable and have great potential benefits, but are unlikely to have immediate impact on self-harm rates. Training public services staff to be aware of the impacts is a vital first step.

FURTHER READING

• Pathways between early life adversity and adolescent self-harm, September 2019
• Bristol One City Plan, January 2019
• Avon Longitudinal Study of Children and Parents, University of Bristol