A prominent definition, which was initially developed for use in the WHO European regional multicenter study on non-fatal suicidal behavior during the 1990’s and has since been used in several surveillance systems and studies across different countries, is the following:

“An act with non-fatal outcome in which an individual deliberately initiates a non-habitual behavior that, without intervention from others, will cause self-harm, or deliberately ingests a substance in excess of the prescribed dosage, and which is aimed at realizing changes that the person desires via the actual or expected physical consequences” (19).

De Leo et al. (20) simplified this definition as follows:

“A non-habitual act with non-fatal outcome that the individual, expecting, or taking the risk, to die or to inflict bodily harm, initiated and carried out with the purpose of bringing about wanted changes”.