The interpersonal theory of suicide attempts to explain why individuals engage in suicidal behavior and to identify individuals who are at risk. It was developed by Thomas Joiner and is outlined in Why People Die By Suicide.[1] The theory consists of three components that together lead to suicide attempts. According to the theory, the simultaneous presence of thwarted belongingness and perceived burdensomeness produce the desire for suicide. While the desire for suicide is necessary, it alone will not result in death by suicide. Rather, Joiner asserts that one must also have acquired capability (that is, the acquired ability) to overcome one's natural fear of death.
A number of risk factors have been linked to suicidal behavior, and there are many theories of suicide that integrate these established risk factors, but few are capable of explaining all of the phenomena associated with suicidal behavior as the interpersonal theory of suicide does. Another strength of this theory lies in its ability to be tested empirically. It is constructed in a way that allows for falsifiability. A number of studies have found at least partial support for the interpersonal theory of suicide.[2][3] Specifically, a systematic review of 66 studies using the interpersonal theory of suicide found that the effect of perceived burdensomeness on suicide ideation was the most tested and supported relationship. The theory’s other predictions, particularly in terms of critical interaction effects, are less strongly supported.[4]