The study highlighted the need to consider aggression towards others while treating self-harming individuals, and vice versa.
London: People who are prone to self-harm are five times more likely to commit violent crimes against others, a new study has found.
Researchers from Karolinska Institutet in Sweden studied about 1,850,525 individuals in total and followed them from age 15. During the study period about 55,185 received self-harm associated clinical care, 66,561 were convicted of a violent crime, and about 8,155 were both exposed to self-harm and convicted of a violent crime.
Researchers found that individuals who had at some time received clinical care for self-harm ran a five-fold risk of being convicted for a violent crime compared with those who had never received care for self-harm.
Almost as many men as women received clinical care for self-harm during the study period. The risk of violent crime conviction was particularly high for self-harming women with comorbid substance abuse, with a seven times increased risk for violent crime conviction, compared to women who had never received clinical care for self-harm, researchers said.
Even after controlling for relevant confounders, such as psychiatric co-morbidity and socioeconomic factors, self-harm was still associated with a doubled risk of violent crime conviction, a finding that remained when men and women were analysed separately.
“A susceptibility to self-harm seems to increase the risk of violent expression, but we found no support for the hypothesis that self-harm causes violence crime,” said Hanna Sahlin of Karolinska Institutet.
The research concluded that self-harm behaviour and violent criminality is a manifestation of a common underlying vulnerability.
“When we reversed the analysis and examined the risk of self-harm in individuals convicted of a violent crime, we found a similar association,” Sahlin said. “Taken together, this suggests that self-harm behaviour and violent criminality is a manifestation of a common underlying vulnerability,” she said.
“We need to ask about aggressive behaviour towards others when we assess and treat self-harming individuals, but we also need to ask about self-harm when we assess and treat aggressive individuals,” Sahlin said.
The study was published in the journal JAMA Psychiatry.