Suicide is the second leading cause of death among university students. Insomnia symptoms have been established as a risk factor for suicidal ideation and feelings of thwarted belongingness have...Show moreSuicide is the second leading cause of death among university students. Insomnia symptoms have been established as a risk factor for suicidal ideation and feelings of thwarted belongingness have been proposed to explain the link between insomnia symptoms and suicidal ideation. The purpose of this study was to investigate the association between insomnia symptoms and suicidal ideation, with thwarted belongingness mediating the relationship, in a sample of Dutch university students. The study assessed participants crosssectionally (n = 218) and after six months (n = 83). Participants completed the Insomnia Severity Index, Beck Scale for Suicide Ideation, the Interpersonal Needs Questionnaire, Beck Depression Inventory, and the Beck Anxiety Inventory. Logistic regression and mediation analyses were conducted. Symptoms of depression and anxiety were controlled for. Crosssectionally, insomnia symptoms were significantly associated with suicidal ideation. When adjusting for symptoms of depression and anxiety, the association became nonsignificant and only symptoms of depression emerged as an independent predictor. Thwarted belongingness mediated the relationship between insomnia symptoms and suicidal ideation cross-sectionally. When depressive symptoms were controlled for, the mediation model became nonsignificant. Longitudinally, results suggested no predictive effect of insomnia symptoms on suicidal ideation and no mediation effect of thwarted belongingness on the relationship. The results did not support insomnia symptoms as an independent risk factor for suicidal ideation in university students, which underscores the need for more rigorous research to clarify this relationship for the future.Show less