The Interpersonal Theory of Suicide posits that two unmet interpersonal needs, thwarted belongingness and perceived burdensomeness, interact to predict suicide desire. These two constructs are frequently assessed using the 15-item Interpersonal Needs Questionnaire (INQ-15); however, this measure has never been validated in military service members. The current study analyzed the psychometric properties of the INQ-15 in a sample of (N = 1096) military personnel stationed overseas. Results indicated that the two-factor model of the INQ-15 had a poor model fit in this population; however, a bifactor model with two specific factors representing TB and PB demonstrated good fit. As seen in previous research, perceived burdensomeness was more strongly related to suicidal ideation severity than thwarted belongingness. Implications and future directions for research are discussed.
Keywords: Suicide; interpersonal needs; perceived burdensomeness; psychometrics; suicidal ideation; thwarted belongingness.
© 2022 Society for Military Psychology, Division 19 of the American Psychological Association.