Background: Suicidality has become the most common cause of death for younger individuals. With increasing suicide rates across the globe suicidal ideation (SI) has received a lot of attention not...Show moreBackground: Suicidality has become the most common cause of death for younger individuals. With increasing suicide rates across the globe suicidal ideation (SI) has received a lot of attention not only because of its occurrence in a non-clinical population but also due to its predictive quality of suicidal behavior. Recent literature arising out of the COVID-19 era indicated that high loneliness is a predictor higher SI. Current theories of SI emphasized the identification of external risk factors for SI but have neglected the participating role of the self during SI. Objective: That is, the present paper aimed to introduce the ego function mentalization from the school of psychoanalysis and psychodynamics to illuminate the limitations of current SI theories. Consequently, this study investigated the moderating effects of mentalization on the link between loneliness and SI. Method and results: In this cross-sectional design, students aged 17-26 (N=112) filled out online, self-report questionnaires measuring SI, loneliness, and mentalization. The bivariate correlation test showed that loneliness is positively associated with loneliness (rs = .6, p < .001). Findings from the hierarchical analysis indicate that this positive relationship is moderated by mentalization (R2 = .425, b = .01, F (1,108) = 5.01, p = .027). In particular, the interaction effect of loneliness and SI suggests a strengthening of the link between loneliness and SI as mentalization scores increase. Conclusion: The study highlights the importance of mentalization as a moderator of the critical relationship between loneliness and SI in a non-clinical juvenile sample. In essence, the findings invite clinicians to introduce ego functions when investigating the emergence, maintenance, and progression of self-destructive ideation.Show less