Personality Assessment Inventory suicidality scales: Suicidal Ideation (SUI), Suicide Potential Index (SPI), and S_Chron in an Afghanistan/Iraq-era active and Veteran military sample.

INTRODUCTION: This study validated Personality Assessment Inventory (PAI) Suicidal Ideation (SUI), Suicide Potential Index (SPI), and S_Chron scales against chronic and acute suicide risk factors and symptom validity measures.

METHODS: Afghanistan/Iraq-era active-duty and Veteran participants completed a prospective study on neurocognition (N = 403) that included the PAI. The Beck Depression Inventory-II (specifically item 9) administered at two time points assessed acute and chronic suicide risk; the Beck Scale for Suicide Ideation item 20 identified history of suicide attempts. Major depressive disorder (MDD), posttraumatic stress disorder (PTSD), and traumatic brain injury (TBI) were evaluated using structured interviews and questionnaires.

RESULTS: All three PAI suicide scales were significantly related to independent indicators of suicidality, with the largest effect for SUI (AUC 0.837-0.849). All three suicide scales were significantly related to MDD (r = 0.36-0.51), PTSD (r = 0.27-0.60), and TBI (r = 0.11-0.30). The three scales were not related to suicide attempt history for those with invalid PAI protocols.

CONCLUSIONS: Although all three suicide scales do show significant relationships to other indicators of risk, SUI showed the highest association and greatest resistance to response bias.