The risk of experiencing intimate partner violence may accumulate over time among people who experienced childhood maltreatment when they were younger, finds a new study led by UCL researchers.
For the study, published in Molecular Psychiatry, researchers analysed data from 12,794 participants born in England and Wales from the Twins Early Development Study (TEDS).
TEDS began in 1994 and has followed twins born in England and Wales throughout their childhood, adolescence and into early adulthood. The twins and their families complete questionnaires and take part in interviews about different environmental and individual factors that might have been influencing them throughout their lives.
By studying the differences between identical and non-identical pairs of twins, researchers use the data to understand how genes and environments affect abilities, behaviours and mental health.
In the new study, the researchers found that participants who reported childhood maltreatment (such as emotional, physical or sexual abuse, and emotional or physical neglect) were three times more likely to experience intimate partner violence at the age of 21 compared to their peers.
However, the risk of domestic abuse continued to grow over time. And by the time the participants reached the age of 26, they were four times more likely to have encountered intimate partner violence if they had experienced childhood maltreatment earlier in life compared to peers of the same age.
Lead author Dr Patrizia Pezzoli (UCL Psychology & Language Sciences) said: "Our findings are in line with past research, which generally reports a three to six times higher risk for intimate partner violence victimisation among those with a history of childhood maltreatment.
"However, our finding that this risk may accumulate over time is novel. We interpreted this escalation in light of previous evidence that individuals exposed to maltreatment often face gradual restrictions in social networks - for example as a result of having less opportunities to socialise when growing up - potentially heightening their vulnerability to unsafe relationships over time."
As part of their study, the researchers also looked at the reasons why people who experience childhood maltreatment often face a greater risk of abuse in their adult relationships.
They found that childhood maltreatment specifically increases the risk of intimate partner violence over and above both environmental and genetic risk factors.
Meanwhile, environmental influences shared by siblings, such as family dynamics and socioeconomic status, still accounted for a large proportion (42-43%) of the link between childhood maltreatment and intimate partner violence, as did genetic factors (30-33%) that influence behaviour, personality traits and susceptibility to certain conditions, including the likelihood of experiencing or perpetrating violence.
External factors unique to each individual, such as peer groups, life events or personal experiences also accounted for around a quarter (25-27%) of the association between childhood maltreatment and future intimate partner violence.
Dr Pezzoli said: "These distinctions can help us to understand the different pathways through which childhood experiences can impact later life outcomes and inform targeted interventions."
The researchers now hope that their findings can be used to help potentially vulnerable people.
Dr Pezzoli explained: "We hope that our research will allow us to tackle the complex factors that increase risk for certain individuals, creating opportunities for effective prevention and support.
"This research highlights the need for evidence-based support strategies for people affected by childhood maltreatment, ideally before they begin intimate relationships, to help them build a safe and healthy future."
The research was funded by a British Academy/Leverhulme grant awarded to Dr Pezzoli.
