Spanish Validation of the Interpersonal Needs Questionnaire and the Acquired Capability for Suicide Scale Among Mexican University Students.

Introduction: the rate of death by suicide has increased in Mexico, representing a significant public health problem. To prevent and treat this phenomenon, it is crucial to identify reliable suicide risk factors among Mexicans. The Interpersonal Theory of Suicide has demonstrated empirical support for the role of thwarted belongingness, perceived burdensomeness, and acquired capability in the development of suicidal desire and behaviors. The measure of the theory's constructs-the Interpersonal Needs Questionnaire (INQ) and the Acquired Capability for Suicide Scale (ACSS)-has also shown good psychometric qualities.

Objective: translate, culturally adapt and validate these instruments.

Method: 495 university students from Mexico City participated in two independent samples (n = 239; n = 256). For the INQ, the available version in Spanish was used. For the ACSS, the most current version in English was used. Based on the results from the first sample, items were modified, eliminated, or added for the second sample.

Results: the INQ demonstrated good fit (RMSEA = .054, TLI = .97, IFI = .97, NFI = .95) with an internal consistency of .77 and .87 for thwarted belongingness and perceived burdensomeness, respectively. The ACSS obtained similar results (RMSEA = .011, CFI = .99, TLI = .99, IFI = .99, NFI = .91); the internal consistency was .77.

Discussion and conclusions: the Spanish version of the instruments display good psychometric properties and can be used to measure the constructs of the interpersonal theory of suicide. However, further replication is needed to support generalizability in other Spanish-speaking populations.