Suicidal ideation and behaviour may increase when adolescents are exposed to schoolmate and personally known suicides

Suicidal ideation and behaviours are widespread and serious amongst adolescents (Husky et al., 2012). One theory suggests that suicide in this age group is caused by ‘suicide contagion’ (exposure to a suicide may influence an individual to attempt suicide). Ecological studies have indeed demonstrated this and show that suicide rates increase following a highly publicised suicide either from local knowledge or through the media (Gould, 2001). It appears that adolescents are more vulnerable to this effect.

The Canadian Medical Association Journal published a study by Swanson and Colman (2013) which showed that young people exposed to a suicide at school or to a personally known suicide predicted subsequent suicidal ideation and suicide attempts.

Methods

Experts have suggested that ‘suicide contagion’ may occur when individuals attempt suicide after being exposed to another suicide in their friends or peer group

Experts have suggested that ‘suicide contagion’ may occur when individuals attempt suicide after being exposed to another suicide in their group of friends or peers

The authors utilised baseline data from the Canadian National Longitudinal Survey of Children and Youth (which is a population-based nationally representative cohort study involving 16,903 Canadian children between 1994-1995 when participants were 0-11 years old) between 1998-1999 and 2006-2007 with follow up assessments at 2 years. Participants were aged 12-17 years and cycles 3-7 with reported measures of exposure to suicide were used as these included suicidality measurements allowed 2 years follow up. Response rates were over 80% for each wave. The authors stratified by 2-year age groups which maintained independent observations and allowed for possible effect modification by age group. Participants were asked if any schoolmates had died by suicide and whether they personally knew anyone who had died by suicide. Participants were also asked if they had seriously considered attempting suicide in the past year and about their suicidal ideation using items originally from the Ontario Child Health Study.

Results

Results showed:

The research highlighted a relationship between exposure to suicide and suicidal ideation and attempts

Exposure to a schoolmate’s suicide was associated with suicidal ideation at baseline among participants aged:
- 12–13 years (odds ratio [OR] 5.06, 95% confidence interval [CI] 3.04–8.40),
- 14–15 years (OR 2.93, 95% CI 2.02–4.24) and
- 16–17 years (OR 2.23, 95% CI 1.43– 3.48).
This exposure was associated with suicide attempts among participants aged:
- 12–13 years (OR 4.57, 95% CI 2.39–8.71),
- 14–15 years (OR 3.99, 95% CI 2.46–6.45) and
- 16–17 years (OR 3.22, 95% CI 1.62–6.41).
The findings were very similar for individuals who had been exposed to personally known suicides and those exposed to this were associated with suicidality outcomes in all age groups.
At 2 year follow-up, participants aged 12-13 years who had been exposed to a schoolmate’s suicide predicted suicide attempts (OR 3.07, 95% CI 1.05–8.96) and 14–15 years (OR 2.72, 95% CI 1.47–5.04). However, personally knowing the descendent did not influence the risk of suicidality.

Conclusion

The authors conclude:

We found that exposure to suicide predicts suicide ideation and attempts. Our results support school-wide interventions over current targeted interventions, particularly over strategies that target interventions toward children closest to the decedent.

Strengths and limitations

This study had several strengths. The sample size was large and nationally representative. The authors note that they included two important types of suicide exposure (schoolmate’s suicide and personally known suicide).

This research did not take account of the impact that media coverage of suicide can have on young people, which we know is an important factor

Yet, the study did have several limitations. A number of confounding variables could have influenced the results. However, the results showed strong associations between suicide exposure and suicide outcomes among participants aged 12-13 years, so confounding would be unlikely to alter the conclusions.

In addition, exposure variables were assessed using two self-report questionnaires and it is difficult to assess the relationship between the participant and the deceased. The results identified that with exposure to a schoolmate’s suicide, personally knowing the deceased didn’t predict suicidality outcomes. This question warrants future research.

The authors also consider that no information was provided on media exposure following a suicide death in school or in the community, these could have strongly mediated any of the effects. Future research should also consider investigating this issue.

Summary

This research highlights the importance of school-based interventions to target at risk individuals

This longitudinal study clearly shows a strong association between exposure to a schoolmate’s suicide and a personally known suicide and subsequent suicidal ideation and suicide attempts in adolescents aged 12-17 years
The study is a valuable addition to the pre-existing research literature
Interventions should target schools and communities in an attempt to reduce the risk of suicide as well as the distress caused by it