Introduction and aims: Suicide is the second cause of death among young people in Israel. Studies of suicidal behaviour have provided valuable information about the risk factors associated with these behaviours, yet there is not much information about predictors of transitions from suicidal thoughts to actual suicide behaviour. The current study aims to elucidate the mechanisms in which suicidal ideation emerges over time and how suicidal ideation can lead to suicidal actions. We will attempt to determine the effects of risk factors such as psychopathology, non-suicidal self-injury (NSSI) and risk behaviours on suicidal behaviour. This will be examined through the prism of a putative model of youth suicidal behaviour based on the theoretical framework of Joiner’s Interpersonal Theory of Suicide.
Methods: The prospective study design included baseline and two follow-up assessments within a year. Follow-up sample included a total of 708 adolescents from schools throughout Israel. The students completed self-report questionnairesregarding suicide ideation and attempts, psychopathology, life style, socio-demographic background, non-suicidal self-injury, life events and social support.
Results: Within the follow-up year, 9.0 % of the students reported suicidal behaviour. Results indicate that interpersonal distress and internalizing disorders at baseline predicted later levels of suicidal ideation. The effects of interpersonal factors on ideation were partly or fully mediated by internalizing symptoms. We also found that increases in suicidal ideation and in engagement in risk behaviours and NSSI over time were associated with the occurrence of a suicide attempt within the follow up period.
Conclusions: The model identifies the different phases along the path to suicidal behaviour, and risk factors associated with each phase. Hopefully this model will improve our understanding of the short term course of suicidal behaviour among adolescents, which may lead to potential improvements for intervention and prevention.

Keywords: suicide, self-harm, NSSI.