Evidence-based theoretical models outlining the pathways to the development of suicidal ideation may inform treatment. The current research draws from the Interpersonal Theory of Suicide (IPT) and the Integrated Motivational-Volitional (IMV) Model of suicidal behaviour and aims to test the interaction between perceived burdensomeness and thwarted belongingness as proposed by the IPT model, and the defeat-entrapment pathway as proposed by the IMV model, in the prediction of suicidal ideation at 12-month follow-up.

The Scottish Wellbeing Study is a nationally representative prospective study of young people aged 18–34 years (n = 3508) from across Scotland, who completed a baseline interview and a 12-month follow-up (n = 2420). The core factors from both the IPT (perceived burdensomeness and thwarted belongingness) and the IMV model (defeat, internal and external entrapment) were measured alongside demographics, depressive symptoms and suicidal ideation at baseline. At 12-month follow-up, suicidal ideation was assessed again.

In multiple regression analysis perceived burdensomeness and internal entrapment, with baseline suicidal ideation, predicted 12-month suicidal ideation. No support for the interaction between perceived burdensomeness and thwarted belongingness in predicting 12-month suicidal ideation was found. However, there was evidence that internal, but not external, entrapment mediated the relationship between defeat and 12-month suicidal ideation, but no support was found for the moderation of burdensomeness and belongingness on the entrapment to suicidal ideation pathway.

The current findings highlight the importance of targeting perceived burdensomeness and internal entrapment to reduce the likelihood that suicidal ideation emerges in at risk individuals.