Abstract

Background
A range of factors including mental disorders, adverse events and history of self-harm are associated with suicide risk. Further examination is needed of the characteristics of suicides which occur without established risk factors, using national surveillance systems.

Methods
Data on all suicides in Ireland from 2015 to 2017 were drawn from the Irish Probable Suicide Deaths Study (IPSDS). Variables examined included socio-demographics, psychiatric history and precipitant stressors. Suicide data were linked with data on prior self-harm from the National Self-Harm Registry Ireland (NSHRI). Latent Class Analysis (LCA) was used to identify sub-groups of suicide cases.

Results
Of the 1809 individuals who died by suicide, 401 (22.2 %) had a history of hospital-treated self-harm. Four distinct profiles of suicides were identified. One group was marked by high levels of prior self-harm and mental health conditions. Two of the groups included few individuals with a history of self-harm but had notably high levels of mental health conditions. These two groups had relatively high levels of reported chronic pain or illness but differed in terms of socio-demographics. The final group, predominantly male, had markedly low levels of mental health conditions or self-harm but high levels of personal stressors and substance use.

Limitations
The use of coronial data may be limited by bias in the collecting of information from the deceased’s family members.

Conclusions
A sub-group of suicide cases exists without any psychiatric or self-harm history but with salient occupational or health-related proximal stressors. Suicide prevention interventions should include occupational settings and should promote mental health literacy.

Introduction

Suicide is a major global health concern, with over 700,000 people around the world dying by suicide every year (WHO, 2021). The causes of suicide are complex, encompassing individual factors such as genetic influences and mental disorders, contextual factors such as family influences, history of abuse, socioeconomic conditions, exposure to suicidal behaviour by others, access to means for a suicidal act and lack of support in a crisis (Hawton and Pirkis, 2017). Self-harm is associated with a significant risk of subsequent death through suicide (Hawton et al., 2015; Vuagnat et al., 2019). Risk of suicide among individuals in the year after a suicide attempt has been estimated to be up to 100 times higher than matched community controls (Tidemalm et al., 2015), while a meta-analysis of psychological autopsy studies reported that self-harm history was associated with a ten-fold increase in suicide risk (Favril et al., 2022). A recent national Irish study reported one-year risk of suicide following an episode of hospital-treated self-harm to be 0.8 % (Griffin et al., 2023).

Conclusion

The majority of suicides occurred in individuals with no prior history of hospital-treated self-harm. Those who had previously presented to hospital had higher levels of known risk factors from socio-demographic and psychiatric domains. Among males in particular, a sub-group was identified without any psychiatric history and low levels of known risk factors, but with salient occupational or health-related proximal stressors. Suicide prevention interventions should include occupational settings as well as promoting support for those with chronic physical health conditions.

While mental illness remains a major risk factor, these findings suggest that emphasis needs to be placed on the broader psychosocial issues which may influence the pathway to suicide. In addition, it may be that the relative contribution of mental health conditions and other factors is fluid in relation to both life stage and life circumstances.