Addressing the lack of comparability of research results around the world, a systematic literature review of existing nomenclatures was conducted. After distinguishing the concepts of nomenclature and classification, 13 contributions to nomenclature of suicidal behavior are described and summarized using outcome and intent as guiding concepts for analysis. The issue of what is being defined in nomenclatures is fundamental and impacts the way intent and outcome are used. The existing confusion between classification and nomenclature stems from conflicting purposes of the nature of definition; that is, to communicate concepts versus to be descriptive of reality.

ObjectivesExplore international consensus on nomenclatures of suicidal behaviours and analyse differences in terminology between high-income countries (HICs) and low/middle-income countries (LMICs).DesignAn online survey of members of the International Organisation for Suicide Prevention (IASP) used multiple-choice questions and vignettes to assess the four dimensions of the definition of suicidal behaviour: outcome, intent, knowledge and agency.SettingInternational.ParticipantsRespondents included 126 individuals, 37 from 30 LMICs and 89 from 33 HICs. They included 40 IASP national representatives (65% response rate), IASP regular members (20% response rate) and six respondents from six additional countries identified by other organisations.Outcome measuresDefinitions of English-language terms for suicidal behaviours.ResultsThe recommended definition of ‘suicide’ describes a fatal act initiated and carried out by the actors themselves. The definition of ‘suicide attempt’ was restricted to non-fatal acts with intent to die, whereas definition of ‘self-harm’ more broadly referred to acts with varying motives, including the wish to die. Almost all respondents agreed about the definitions of ‘suicidal ideation’, ‘death wishes’ and ‘suicide plan’. ‘Aborted suicide attempt’ and ‘interrupted suicide attempt’ were not considered components of ‘preparatory suicidal behaviour’. There were several differences between representatives from HICs and LMICs.ConclusionThis international opinion survey provided the basis for developing a transcultural nomenclature of suicidal behaviour. Future developments of this nomenclature should be tested in larger samples of professionals, including LMICs may be a challenge.

To address the lack of comparability around the world, we conducted a systematic review of existing definitions of suicide and suicidal behaviors. In the literature, four key features appear to cover the vast majority of concepts underpinning definitions: agency, knowledge of a potential fatal outcome, intent, and outcome. Intent and outcome appear to be the most consensual features of definitions of suicide, albeit revealing interesting conceptual variations. The four key features could be used to devise a research tool able to explore the meanings of suicide across different countries and different cultures.