Ideation-to-action theories of suicide: a conceptual and empirical update

This review provides a conceptual and empirical update regarding ideation-to-action theories of suicide. These theories - including the interpersonal theory (IPTS), integrated motivational-volitional model (IMV), three-step theory (3ST), and fluid vulnerability theory (FVT) - agree that, firstly, the development of suicidal ideation and secondly, the progression from suicide desire to attempts are distinct processes with distinct explanations. At the same time, these theories have some substantive differences. A literature review indicates that the IPTS has received extensive examination, whereas evidence has only begun to accumulate for the other theories. Based on current evidence, we offer three inferences. First, the capability for suicide meaningfully distinguishes those who have attempted suicide (attempters) from those with suicidal desire who have not attempted (ideators). This encouraging finding is broadly consistent with the IPTS, IMV, and 3ST. The nature and measurement of capability warrant further attention. Second, consistent with the 3ST, accumulating evidence suggests that pain and hopelessness motivate suicidal desire more than other factors. Third, the FVT, which is largely compatible with other theories, may be best equipped to explain the non-linear time-course of suicidal ideation and attempts. Longitudinal studies over various time-frames (minutes, hours, days, weeks, months) are necessary to further evaluate and elaborate ideation-to-action theories of suicide.