Suicide Cluster

Primary reference(s)

Joiner, T. E., Jr., 1999. The clustering and contagion of suicide. Current Directions in Psychological Science, 8(3), 89–92. DOI: 10.1111/1467-8721.00021. Accessed 30 May 2025.

PHE, 2019. Identifying and Responding to Suicide Clusters: A practice resource. Public Health England (PHE). Accessed 30 May 2025.

Annotations

Key relevant UN convention / multilateral treaty

Not relevant.

Drivers

The main drivers of mass suicides are associated with political and religious motivation and mental health (Mancinelli et al., 2002); as well as psychological mechanisms of contagion (Haw et al., 2013) and having access to the means of committing suicide. For example, Niederkrotenthaler et al. (2020) showed that reporting of deaths of celebrities by suicide appears to increase the number of suicides by 8-18% in the subsequent 1-2 months, and information on the method of suicide was associated with an increase of 18-44% in the risk of suicide by the same method. Studies on the effects of media items covering novel suicide methods have been useful in understanding the interplay between media and suicide methods, for example, charcoal burning in parts of Asia (Lee et al., 2014).

Mental disorders and the harmful use of alcohol contribute to many suicides around the world (WHO, 2025). Cultural variability in suicide risk is also apparent, with culture having roles both in increasing risk and in protection from suicidal behaviour (WHO, 2014). In the past half-century, many countries have decriminalised suicide, making it easier for those with suicidal behaviours to seek help (WHO, 2023). Public Health England recommends the development of a Suicide Cluster Response Plan (PHE, 2019). WHO recommends to Member States in the Mental Health Action Plan to lead and coordinate a multisectoral strategy that combines universal and targeted interventions for: promoting mental health and preventing mental disorders; reducing stigmatization, discrimination and human rights violations; and which is responsive to specific vulnerable groups across the lifespan and integrated within the national mental health and health promotion strategies (WHO, 2018).

Haw et al. (2013) reported in their review of the literature for suicide clusters that the following as being significant for suicide risk factors:

• male gender, adolescent or young adult,
• a family history of suicide, a family history of alcohol abuse,
• personal history of unstable family or home life, poor educational experience, employment problems, loss of traditional ways, victim or witness of abuse, experienced violence, violence toward others, history of arrest/antisocial behaviour, experienced death of close friend or relative
• psychiatric history with a history of self-harm or threats of self-harm/suicide, previous psychiatric hospitalization, drug and/or alcohol abuse depression; and life events and psychological factors such as recent relationship breakup or threat of breakup, social isolation, inability to express feelings, easily emotionally hurt or offended, poor self-esteem and direct involvement with another cluster victim (Haw et al., 2013).

Impacts

As an example, Jones et al. (2013) reported on a possible suicide cluster: in early 2008 unprecedented attention was given by national and international news media to a suspected suicide cluster among young people living in Bridgend, Wales. Analysis of all deaths by suicide, undetermined intent, accidental poisoning and accidental hanging (possible suicides) identified a temporo-spatial cluster (p = 0.029) involving 10 deaths amongst 15–34-year-olds centred on the County Borough of Bridgend for the period 27 December 2007 to 19 February 2008. This cluster was smaller, shorter in duration, and predominantly later than the phenomenon that was reported in national and international print media (Jones et al., 2013). 

Another cluster was reviewed by Hill et al. (2023). They identified coroner-confirmed cases of suicide (ICD-10 codes X60–X84) in young people (aged 10–25 years) and adults (aged 26 and above) who died in Australia between 1 January 2016 and 31 December 2020 using the National Coronial Information System (NCIS). They found that between 1 January 2016 and 31 December 2020, eight hotspots (clusters of high relative risk) were detected across six Australian states and territories. These hotspot communities comprised 228 young people, accounting for 12% of youth suicides during the study period. The identification of geographic hotspots of suicide has important implications for suicide prevention, including directing resources to areas where the need is greatest. Findings from this study highlight both the risk and protective role that the mental health workforce supply may play in the spatial distribution of youth suicide clusters. These findings have important implications for the provision of postvention support in the aftermath of a suicide and for the prevention of suicide clusters. Improving access to mental health services can be achieved by increasing the capacity of the mental health workforce, and through the introduction of novel telehealth and digital interventions (Hill et al., 2023).

Multi-hazard context

Mass suicide may be triggered by the occurrence of other hazards, in particular in the case of other societal hazards, such as those involving violence, conflict or financial shock.

Risk Management

Media, and social media, can play a role in suicide prevention in vulnerable groups during a cluster (PHE, 2019), protecting vulnerable or impressionable individuals, because appropriately responding to single suicides can reduce the risk of a spread of suicidal behaviour (PHE, 2019). To that end, social media may adopt content moderation practices to filter messages that may induce suicide.  

Trinh et al. (2024) have developed CDC guidance that is designed to support and assist communities in the assessment and investigation of suspected suicide clusters that can ultimately guide public health action (e.g., community response) to prevent suicide. Investigating a suspected cluster requires substantial time and resources for the lead agency and community. Ideally, the committee and liaison are prepared to receive concerns, engage key partners, and assess and investigate suspected clusters. This CDC guidance provides direction for a carefully planned and implemented process. Having an established approach can help an agency and community prepare the infrastructure and resources to readily act when suicide clusters are suspected or confirmed. Although suicide clusters comprise a small proportion of suicides, a suicide cluster or the perception of a suicide cluster can greatly affect communities (Trinh et al., 2024).

Monitoring

Despite evidence that many deaths are preventable, suicide is often a low priority for governments and policymakers (WHO, 2014). Notwithstanding, many suicides happen without forewarning and, in such circumstances, easy access to a means of suicide – such as pesticides, or hanging – can make the difference as to whether a person lives or dies (WHO, 2014).