Over the past two weeks, two students who survived the school shooting at Marjory Stoneman Douglas High School in Parkland, Florida have died by suicide, amplifying the tragedy that community has experienced.

Is this yet another instance of a phenomenon some have dubbed “suicide contagion?”

In recent years, research has shown that suicide has the potential to spread through social networks. If someone is exposed to the suicide attempt or death of a friend, it increases that person’s risk of suicidal thoughts and attempts.

The consequences can be devastating for families, classmates and townspeople, who are left struggling to understand why clusters of suicides are occurring in their communities. In recent years, we’ve seen this play out in Newton, Massachusetts and Palo Alto, California.

But the role of suicide contagion is perhaps one of the least understood aspects of suicide, which puts us at a significant disadvantage when it comes to designing effective strategies to prevent the spread of suicides.

In a 2015 study, we examined whether knowledge of a friend’s suicide attempt would influence someone’s own risk of attempting suicide.

Using longitudinal data, we discovered that adolescents who know about a friend’s suicide attempt are nearly twice as likely to attempt suicide one year later. Youth who lose a friend to suicide are at an even higher risk. Interestingly, adolescents whose friends didn’t tell them about their suicide attempts didn’t experience a significant increase in their risk of suicide one year later.

Our study has several interesting implications for suicide prevention.

First, experiencing the suicide attempt or death of a friend appears to change adolescents’ risk profile in a meaningful way. We’re all exposed to suicide at some point, whether it’s through reading Romeo and Juliet or simply watching the news. But exposure to a friend’s suicide attempt or death appears to transform the distant idea of suicide into something very real: a meaningful, tangible cultural script that youth may follow to cope with distress.

Second, following the old adage “birds of a feather flock together,” some have argued that depressed teens may simply befriend one another, which explains why groups of friends have similar suicide rates – and which contradicts the theory of suicide contagion.

However our findings add to the literature indicating that suicide contagion is not merely a product of adolescents choosing friends who are similarly vulnerable to suicide. If contagion didn’t matter, knowledge about suicide attempts shouldn’t matter either. Rather, it’s apparent that only if youth know about their friend’s suicide attempt does their suicide risk spike.

So what do we do with this knowledge?

All about ‘postvention’

It’s clear that suicide is not simply a product of psychological illness or psychological risk factors. Exposure to suicide, even if it’s just an attempt, is emotionally devastating, and youth need support when coping with the complex emotions that follow. Here, prevention – or, as it’s sometimes called, “postvention strategies” – becomes crucial.

One clear implication of our work is that during screenings for suicide risk, youth should always be asked whether or not they’ve known someone who has attempted or died by suicide. In fact, many reliable tools for screening youth for suicide include questions about exposure to suicide.

This seems reasonable. But then things get murky.

Given what our research has shown, it’s only natural to wonder whether or not someone who has attempted suicide should be discouraged from talking about it. There’s the fear that if we talk about suicide, we may be inadvertently promoting it.

At the same time, if we encourage people to not talk about suicide – particularly young people – we might miss opportunities to help those who are suffering and contemplating taking their own lives.

Furthermore, feeling like you belong to a group – supported by friends and family, having a healthy social life – is essential to preventing suicide. If we encourage young people to not talk about suicide, we may unintentionally increase suicidal adolescents’ feelings of isolation, which contributes to risk of suicide.

Because of the pervasive stigma of mental illness and suicide, it’s often very difficult for people to admit they need help. So instead of encouraging silence on the topic of suicide, it may be better to train adolescents how to respond appropriately when a friend discloses a suicide attempt or suicidal thoughts.

Luckily, evidence-based programs like Question, Persuade, Refer and SOS Signs of Suicide exist. These can teach young people strategies for getting friends help from appropriate sources. Incidentally, these programs are often offered in schools.

Additionally, it’s important for parents, teachers and coaches to feel comfortable talking about suicide; they need to be well-versed in the proper responses, and realise that a suicide attempt can have a ripple effect that reverberates beyond the individual.

After all, it’s when adolescents are left alone to cope with their friends’ distress that they become most vulnerable to succumbing to the same suicidal ideation and behaviors.

If you are having thoughts of suicide, call the National Suicide Prevention Lifeline at 1-800-273-8255 (TALK). The website is National Suicide Prevention Lifeline.

Anna Mueller , Assistant Professor of Comparative Human Development, University of Chicago and Seth Abrutyn, Assistant Professor of Sociology, University of Memphis.

This article first appeared on The Conversation.