Self-harm may be socially contagious among adolescents

Faculty of Medicine
Epidemiologist Dr. Ian Colman finds teens much more likely to harm themselves when they know someone who has.

By Jessica Sinclair
Research Writer

A study led by University of Ottawa epidemiologist Dr. Ian Colman suggests that non-suicidal self-injury—behaviours like cutting oneself without the intent to die—may be contagious among teenagers. In a study using data collected in 2014 from more than 1,400 Ontario youth between the ages of 14-17, Dr. Colman and his team looked at answers to the question, “Has a friend of yours ever hurt themselves without the intention to die?”

When the answer to that question was ‘Yes’, the respondent was between two and three times as likely to answer ‘Yes’ to the question of whether they have thought about, or done, the same. Previous studies of suicide contagion suggest that whether the exposure comes from a personal friend or a school mate the teen doesn’t even know, the effect is similar. The results are of particular concern because, apart from being a sign of acute distress, non-suicidal self-injury is a predictor of later suicidal behaviour. It’s also a lot more widespread.

“Non-suicidal self-injury is much more common than suicide attempts—twice as common in this study—and many, many times more common than death by suicide,” says Dr. Colman.

Dr. Colman’s study builds on previous research showing that teens who are exposed to suicide among their peers are more than twice as likely to demonstrate suicidal behaviour or harbour suicidal thoughts than those who are not exposed. This sort of communication of ideation and behaviour is a form of contagion, and its spread can be tracked by epidemiologists just as physically communicable diseases are studied.

Knowing that suicide is made more likely by knowledge about someone else’s suicide, societal measures have been put in place to protect vulnerable populations from exposure. Where media follow voluntary guidelines to refrain from placing the word ‘suicide’ in a headline, detailing a person’s method of suicide, or identifying a single cause of someone’s suicide (ex.: bullying), communities are able to dampen the spikes in suicide that otherwise accompany coverage of a person’s suicide.

 Less obvious are the measures that can slow or protect against socially contagious behaviours among teens, who can be expected to communicate freely among themselves, without referring to guidelines. Expert advice on this remains the same: talk with your teens.

“There’s a strong belief that a parent talking to their child about suicide may increase the risk of suicide or self-harm. There is very little evidence to support that,” says Dr. Colman.

Conversations with a trusted adult who lends a listening ear, with no threat of judgment, can be helpful throughout adolescence, including for someone who is having thoughts of self-harm.