Researchers think that violent crime and self-harm are both carried out by people who are extra vulnerable toward impulsive and aggressive behaviour. (Photo: Shutterstock / NTB scanpix)
Researchers think that violent crime and self-harm are both carried out by people who are extra vulnerable toward impulsive and aggressive behaviour. (Photo: Shutterstock / NTB scanpix)

Self-harm links to violence against others

Researchers behind a Swedish study do not think that self-harm leads to violent crimes. But there is an underlying association between deliberate self-harm and violent criminality.


A study of a huge cohort of Swedes conducted by researchers at Karolinska Institute finds a link between self-harm and violent criminality.

Persons who have deliberately injured themselves run twice the risk of being convicted of violent crimes later in life, according to the study published in the journal JAMA Psychiatry.

Not a causal relationship

The researchers underscore that they do not think people become violent criminals automatically because of their self-harm tendencies.

“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,” says Hanna Sahlin, one of the researchers behind the study, in a press release.

The researchers think rather that violent criminality and self-harm both have roots in a common underlying vulnerability for impulsive and aggressive behaviour. This might be attributed to anything from chemical imbalances in the brain to difficulties controlling emotions.

Self-harm can be a symptom

The researchers stress that self-harm ought to be viewed as an early symptom of an underlying problem. This is nothing novel for others who work with self-harm patients.

“Self-harm is often one of many symptoms seen among youths who have mental problems and burdensome experiences in their lives,” said Anita Johanna Tørmoen of the University of Oslo regarding a story published by ScienceNordic’s Norwegian partner

Tørmoen wrote her doctoral thesis on treatment of young self-harming individuals. In her work published by the University of Oslo it was seen that self-harm behaviour is most prevalent among persons who already are burdened with depression, eating disorders, use of drugs and alcohol as well as other behaviour problems.

Looked at lives of 1.8 million Swedes

The Swedish study looked at the statistics covering all 1.8 million Swedes born between 1982 and 1998. Over fifty thousand of them received clinical treatment for self-harming. These individuals were five times more likely than the rest of the population to be convicted of violent crimes.

Nine out of ten of the intentionally self-harmers had poisoned themselves with medications or other substances – or they had cut themselves. 

Even when the researchers made adjustments for confounders – other factors which tend to have an impact, such as mental health, parental education levels and family incomes – they found that self-harmers ran twice the general Swedish population’s risk of being convicted of violent crimes.

“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,” says Sahlin.

The study found that self-harmers also are more likely to have run-ins with the law for engaging in violent crimes than engaging in non-violent ones. The researchers also saw that female self-harmers ran a higher risk of being convicted of crimes than their male counterparts.


Read the Norwegian version of this article at

Translated by: Glenn Ostling

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