The article presents the interpersonal theory of suicidal behavior, which posits that the most dangerous form of suicidal desire is caused by the simultaneous presence of two interpersonal constructs: thwarted belongingness and perceived burdensomeness. The theory also distinguishes between the desire to engage in suicidal behavior and the capability to do so, suggesting that the capability emerges through habituation and opponent processes in response to repeated exposure to painful or fear-inducing experiences. The authors review empirical evidence supporting various risk factors for suicide, including mental disorders, past suicide attempts, social isolation, family conflict, unemployment, and physical illness. They argue that current theories of suicide are insufficient to explain the diverse array of risk factors and the imprecision of these factors in predicting suicidal behavior. The interpersonal theory aims to address these limitations by providing a more precise and comprehensive framework that can account for both suicidal ideation and suicide attempts. The theory is structured around three central constructs: thwarted belongingness, perceived burdensomeness, and acquired capability, with four hypotheses outlining the causal pathway from these constructs to suicidal behavior. The article includes detailed descriptions of these constructs and their relationships to empirically supported risk factors, aiming to invite scientific inquiry and potential falsification of the theory's hypotheses.The article presents the interpersonal theory of suicidal behavior, which posits that the most dangerous form of suicidal desire is caused by the simultaneous presence of two interpersonal constructs: thwarted belongingness and perceived burdensomeness. The theory also distinguishes between the desire to engage in suicidal behavior and the capability to do so, suggesting that the capability emerges through habituation and opponent processes in response to repeated exposure to painful or fear-inducing experiences. The authors review empirical evidence supporting various risk factors for suicide, including mental disorders, past suicide attempts, social isolation, family conflict, unemployment, and physical illness. They argue that current theories of suicide are insufficient to explain the diverse array of risk factors and the imprecision of these factors in predicting suicidal behavior. The interpersonal theory aims to address these limitations by providing a more precise and comprehensive framework that can account for both suicidal ideation and suicide attempts. The theory is structured around three central constructs: thwarted belongingness, perceived burdensomeness, and acquired capability, with four hypotheses outlining the causal pathway from these constructs to suicidal behavior. The article includes detailed descriptions of these constructs and their relationships to empirically supported risk factors, aiming to invite scientific inquiry and potential falsification of the theory's hypotheses.