Suicidal Ideation and Interpersonal Needs: Factor Structure of a Short Version of the Interpersonal Needs Questionnaire in an At-Risk Military Sample

Abstract

Objective: The interpersonal-psychological theory of suicide posits that perceived burdensomeness (PB; i.e., the belief that others would be better off if one were dead) and thwarted belongingness (TB; i.e., the belief that one lacks meaningful social connections) are both necessary risk factors for the development of suicidal ideation. To test these relations, measures are needed that are well validated, especially in samples of at-risk adults. Method: The current study was designed to examine the factor structure of an eight-item version of the Interpersonal Needs Questionnaire (INQ) in a sample of 405 U.S. past and current military personnel (M_age = 31.57 years, SD = 7.28; 90.4% male) who endorsed either current suicidal ideation and/or a past suicide attempt. Analyses were conducted using confirmatory factor analysis (CFA). Results: A bifactor model comprising a general factor, labeled interpersonal needs, and two specific factors, labeled PB and TB, fit the data best. The general factor captured a high proportion of overall variance (81.9%). In contrast, the TB factor captured only a modest amount of variance in items meant to capture this factor (59.1%) and the PB factor captured very little variance in items meant to capture this factor (13.5%). Further, only the interpersonal needs factor was associated with lifetime and past-week suicidal ideation as well as suicidal ideation frequency and duration. Conclusions: The current findings indicate that, for the INQ-8 in high-risk military personnel, a general interpersonal needs factor accounted for the relations PB and TB share with suicidal ideation.

Funding

This study is supported by a Department of Defense Grant (W81XWH-13-2-0032; PI: Stecker) and a Department of Veteran Affairs Clinical Sciences Research and Development Career Development Award (CX000845; PI: Gros). The views expressed in this article are those of the authors and do not necessarily reflect the position or policy of the Department of Veterans Affairs or the U.S. government. There are no conflicts of interest.

Notes

1. The INQ-8 was initially created for use in Department of Defense–funded investigations. Items were selected based on factor analyses of existing data sets that included longer versions of the INQ (e.g., INQ-25). The four items that consistently loaded most strongly onto the thwarted belongingness factor (“These days, other people care about me”; “These days, I feel like I belong”; “These days, I am close to other people”; and “These days, I think I am an asset to the people in my life”) and the four items that consistently loaded most strongly onto the perceived burdensomeness factor (“These days, the people in my life would be better off if I were gone”; “These days, the people in my life would be happier without me”; “These days, I feel like a burden on the people in my life”; and “These days I think I make things worse for the people in my life”) were retained for the INQ-8.

Additional information

Funding

This study is supported by a Department of Defense Grant (W81XWH-13-2-0032; PI: Stecker) and a Department of Veteran Affairs Clinical Sciences Research and Development Career Development Award (CX000845; PI: Gros). The views expressed in this article are those of the authors and do not necessarily reflect the position or policy of the Department of Veterans Affairs or the U.S. government. There are no conflicts of interest.

Notes on contributors

Nicholas P. Allan

Nicholas P. Allan, PhD, Daniel F. Gros, PhD, and Tracy Stecker, PhD, are affiliated with Mental Health Service, Ralph H. Johnson Veterans Affairs Medical Center, and the Department of Psychiatry and Behavioral Sciences, Medical University of South Carolina, both in Charleston, South Carolina. Melanie A. Hom, MS, and Thomas E. Joiner, PhD, are affiliated with Department of Psychology, Florida State University, Tallahassee.

Daniel F. Gros

Nicholas P. Allan, PhD, Daniel F. Gros, PhD, and Tracy Stecker, PhD, are affiliated with Mental Health Service, Ralph H. Johnson Veterans Affairs Medical Center, and the Department of Psychiatry and Behavioral Sciences, Medical University of South Carolina, both in Charleston, South Carolina. Melanie A. Hom, MS, and Thomas E. Joiner, PhD, are affiliated with Department of Psychology, Florida State University, Tallahassee.

Melanie A. Hom

Nicholas P. Allan, PhD, Daniel F. Gros, PhD, and Tracy Stecker, PhD, are affiliated with Mental Health Service, Ralph H. Johnson Veterans Affairs Medical Center, and the Department of Psychiatry and Behavioral Sciences, Medical University of South Carolina, both in Charleston, South Carolina. Melanie A. Hom, MS, and Thomas E. Joiner, PhD, are affiliated with Department of Psychology, Florida State University, Tallahassee.

Thomas E. Joiner

Nicholas P. Allan, PhD, Daniel F. Gros, PhD, and Tracy Stecker, PhD, are affiliated with Mental Health Service, Ralph H. Johnson Veterans Affairs Medical Center, and the Department of Psychiatry and Behavioral Sciences, Medical University of South Carolina, both in Charleston, South Carolina. Melanie A. Hom, MS, and Thomas E. Joiner, PhD, are affiliated with Department of Psychology, Florida State University, Tallahassee.

Tracy Stecker

Nicholas P. Allan, PhD, Daniel F. Gros, PhD, and Tracy Stecker, PhD, are affiliated with Mental Health Service, Ralph H. Johnson Veterans Affairs Medical Center, and the Department of Psychiatry and Behavioral Sciences, Medical University of South Carolina, both in Charleston, South Carolina. Melanie A. Hom, MS, and Thomas E. Joiner, PhD, are affiliated with Department of Psychology, Florida State University, Tallahassee.