A Large-Sample Replication and Validation of the Three-Step Theory of Suicide in Iranian Students

Advancing evidence-based theories of suicide is critical for improving prevention efforts. The purpose of this study was to evaluate the Three-Step Theory of Suicide (3ST) in a sample of Iranian students.

Participants (N = 1017, mean age = 24.2, 58.2% female, 9.4% with a prior suicide attempt) completed measures of psychological pain, hopelessness, connectedness, suicide capability, suicide ideation, suicide attempt, and demographics. Results largely support the theory's central premises.

First, an interactive model of pain and hopelessness accounted for substantial variance (≈51%) in suicide ideation in the overall sample and in women. Among men, the full model (pain, hopelessness, and their interaction) explained similar amount of variance (≈ 52%) in suicide ideation, while the interaction term was not significant and did not explain additional variance over the main effects. Also, as hypothesized, connectedness was protective against escalating suicide ideation severity among those with suicide desire. Finally, suicide capability and its dispositional and practical component predicted suicide attempt history over and above current suicide ideation.

These findings support the validity of 3ST of suicide within the context of a middle-income country. Implications for suicide prevention, clinical intervention and future research directions are discussed.