Evaluating the interpersonal needs questionnaire: Comparison of the reliability, factor structure, and predictive validity across five versions.

Five versions of the Interpersonal Needs Questionnaire (INQ), a self-report measure of perceived burdensomeness and thwarted belongingness, have been used in recent studies (including 10-, 12-, 15-, 18-, and 25-items). Findings regarding the associations between perceived burdensomeness, thwarted belongingness, and suicidal ideation using different versions have been mixed, potentially due to differences in measurement scales. This study evaluated factor structure, internal consistency, and concurrent predictive validity of these five versions in three samples. Samples 1 and 2 were comprised of 449 and 218 undergraduates, respectively; Sample 3 included 114 adolescent psychiatric inpatients. All versions demonstrated acceptable internal consistency. The 10-item version and 15-item version demonstrated the best, most consistent model fit in confirmatory factor analyses. Both perceived burdensomeness and thwarted belongingness consistently predicted concurrent suicidal ideation on the 10-item INQ only. Future research should consider using the 15-item or 10-item versions.