Psychometric properties of the Italian version of the Interpersonal Needs Questionnaire-15 (INQ-15-I)

Objective: The Interpersonal Needs Questionnaire (INQ-15) is a self-report measure of thwarted belongingness and perceived burdensomeness, two constructs associated with suicidal ideation. The objective of the current study was to translate the INQ-15 from English to Italian (INQ-15-I) and to test its factor structure, reliability, and validity in Italian samples.

Method: We examined (a) whether the components of the hypothesized two-factor measurement model are invariant across a community sample (N = 510) and a clinical sample (N = 259); (b) the relations between the INQ-15-I factors and measures of depression (Beck Depression Inventory-II), hopelessness (Beck Hopelessness Scale), and suicidal ideation (Beck Scale for Suicide Ideation); (c) the reliability and psychometric properties of the INQ-15-I.

Results: Results from multigroup confirmatory factor analyses supported the adequacy of the two-factor model to represent thwarted belongingness and perceived burdensomeness. The model is invariant across community and clinical groups, showing excellent fit. The two INQ-15-I scales measure highly intercorrelated constructs. Both significantly correlate with depression, hopelessness, and suicidal ideation, and correlations are high in the clinical sample.

Conclusion: The INQ-15-I is a valid and reliable measure of thwarted belongingness and perceived burdensomeness. Implications for research, assessment, and intervention in suicidal ideation are discussed.