QIMR Berghofer researchers have identified 11 genes associated with people thinking about harming themselves or actually engaging in self-harm.
Self-harm is defined as any behaviour that involves the deliberate causing of pain or injury to oneself, usually as an extreme way of trying to cope with distressing or painful feelings. It can include a range of behaviours such as dangerous drinking, dangerous levels of drug use, self-cutting or burning, eating disorders or other self-inflicted physical harm.
Senior author and study leader, Dr Miguel E. Rentería from QIMR Berghofer’s Genetic Epidemiology group, said they examined genetic data from more than 150,000 people to identify the differences in the DNA of participants who engaged in self-harm compared to those who had not.
“Some of the 11 genes we identified had previously been linked to mental disorders and/or response to stress, but two of the genes had never been associated with any psychiatric or behavioural traits,” Dr Rentería said.
“Seven of the genes were linked to thinking about self-harm ideation and four to acting on those thought, with only one gene linked to both. These findings are important because very little has been known about why some people who struggle with mental illness also engage in self-harm.
“More Australians die by suicide than from skin cancer, but there’s far less known about the biological and medical basis of this behaviour. We hope that better understanding the factors that contribute to self-harm thoughts and behaviour could one day lead to better interventions or follow up therapies to help those at risk.”
The researchers used the results of their analysis to develop a polygenic risk score (PRS) to help estimate a person’s risk of having thoughts of self-harm or self-harm behaviours.
First author and QIMR Berghofer PhD candidate, Adrian Campos, said they then tested the risk score on a sample of more than 8,700 Australian adults.
“We found that the genetic scores for self-harm were associated with thoughts of suicide and suicide attempts, even after adjusting for their individual genetic score for depression,” he said.
“This indicates that we were able to capture some genetic effects that might be specific to self-harm and independent of depression, but we still need to expand the study using a much larger data set to get the test to a point where we can accurately predict behaviour and risk.”
Dr Rentería said it was important to remember that self-harm was preventable and treatable.
“Even when genes play a role in our susceptibility to engage in these kinds of thoughts and behaviours, there are always ways to reduce their effects,” he said.
“Some protective factors include having a supportive family and social relationships, a sense of purpose and control, and connections to good health services. Seeking help is very important, and there are many people and organisations that can help.”
The researchers used data gathered from the UK Biobank and the Queensland Twin Registry.
The study was mainly supported by grants from the National Health and Medical Research Council of Australia, and other funding bodies from the US National Institutes of Health and the UK National Institute of Health Research.