Clustering of suicides in children and adolescents.

Suicide is one of the major causes of death in young people, in whom suicide can occur in clusters. In this Review, we have investigated definitions and epidemiology of such clusters, the factors associated with them, mechanisms by which they occur, and means of intervening and preventing them. Clustering of suicidal behaviour is more common in young people (<25 years) than adults. Suicide clusters can occur as a greater number of episodes than expected at a specific location, including in institutions (eg, schools, universities, psychiatric units, and youth offender units). They might also involve linked episodes spread out geographically. Locations exposed to clusters can be at risk for future clusters. Mechanisms involved in clusters include social transmission (particularly via person-to-person transmission and the media), perception that suicidal behaviour is widespread, susceptible young people being likely to socialise with others at risk of suicidal behaviour, and social cohesion contributing to the diffusion of ideas and attitudes. The internet and social media might have particularly important roles in spreading suicidal behaviour. The effect of suicide clusters on communities and institutions is usually profound. Experience of intervening in clusters has resulted in best practice guidance. This guidance includes preparation for occurrence of clusters in both community and institutional settings. Identification of clusters in the community requires real-time monitoring of suicidal behaviour. Effective intervention is more likely if a cluster response group is established than if no such group exists. The response should include bereavement support, provision of help for susceptible individuals, proactive engagement with media interest, and population-based approaches to support and prevention. Social media can provide a powerful means for disseminating information and reaching young people at risk.