Interpersonal Needs Questionnaire (INQ-15)

1. Abstract

The Interpersonal Needs Questionnaire (INQ-15) is an empirically validated psychometric instrument designed to measure two core interpersonal constructs postulated by Thomas Joiner's Interpersonal Theory of Suicide (IPTS): perceived burdensomeness and thwarted belongingness. According to the IPTS, individuals develop a desire for death when they experience a simultaneous presence of intractable perceived burdensomeness (the subjective belief that one is a liability to others and that others would benefit from one's death) and thwarted belongingness (an unfulfilled, psychologically painful need to belong, marked by isolation, social alienation, and an absence of mutually caring reciprocal relationships). The INQ-15 is a 15-item self-report questionnaire refined from earlier iterative versions (such as the original 25-item and 12-item versions) through rigorous exploratory and confirmatory factor analyses. It comprises two correlated yet distinct subscales: Perceived Burdensomeness (items 1 through 6) and Thwarted Belongingness (items 7 through 15). Respondents rate each statement using a 7-point Likert scale ranging from 1 (Not at all true for me) to 7 (Extremely true for me), with six items reverse-scored to capture preserved social affiliation.

Psychometric evaluations across diverse clinical, non-clinical, undergraduate, military, and geriatric populations demonstrate robust internal consistency reliability, with Cronbach's alpha coefficients typically exceeding α = .85 for perceived burdensomeness and α = .80 for thwarted belongingness. Confirmatory factor analyses consistently substantiate a two-factor oblique structure that demonstrates superior goodness-of-fit indices (CFI > .95, TLI > .94, RMSEA < .06) compared to unidimensional models. Moreover, the INQ-15 displays exceptional convergent validity through statistically significant associations with depressogenic cognitive styles, loneliness, depressive symptom severity, and hopelessness, alongside discriminant validity distinguishing interpersonal distress from generalized somatic affective complaints. Most crucially, extensive longitudinal and cross-sectional investigations corroborate its predictive validity: the statistical interaction between perceived burdensomeness and thwarted belongingness uniquely predicts active suicidal ideation and suicidal intent above and beyond traditional risk markers. Consequently, the INQ-15 serves as a cornerstone instrument in clinical risk assessment protocols, research on suicidology, and cognitive-behavioral intervention outcome tracking.

2. Keywords

Interpersonal Needs Questionnaire, INQ-15, perceived burdensomeness, thwarted belongingness, Interpersonal Theory of Suicide, suicidal ideation, psychometrics, suicidology, risk assessment, confirmatory factor analysis

3. Authors

The conceptualization, item development, and formal psychometric validation of the Interpersonal Needs Questionnaire were conducted by leading clinical psychology researchers specializing in suicidal behavior, cognitive psychology, and interpersonal risk factors:

• Kimberly A. Van Orden, Ph.D. — Associate Professor, Department of Psychiatry, University of Rochester Medical Center, Rochester, NY, USA. Dr. Van Orden is a clinical psychologist whose research investigates late-life suicide prevention, interpersonal risk factors, and social connectedness interventions.
• Tracy K. Witte, Ph.D. — Professor, Department of Psychological Sciences, Auburn University, Auburn, AL, USA. Dr. Witte specializes in empirical evaluations of the interpersonal-psychological theory of suicide and quantitative methodology.
• Kathryn H. Gordon, Ph.D. — Clinical Psychologist and Adjunct Associate Professor, formerly at North Dakota State University, Fargo, ND, USA. Her research focuses on cognitive vulnerabilities, eating disorders, and suicide risk.
• Thomas W. Bender, Ph.D. — Clinical Psychologist, formerly at Florida State University, Tallahassee, FL, USA.
• Thomas E. Joiner, Jr., Ph.D. — The Robert O. Lawton Distinguished Professor of Psychology, Department of Psychology, Florida State University, Tallahassee, FL, USA. Dr. Joiner formulated the Interpersonal Theory of Suicide and has authored over 600 peer-reviewed articles and multiple seminal books on the etiology and prevention of suicidal behavior.

4. Purpose

The fundamental purpose of the Interpersonal Needs Questionnaire (INQ-15) is to provide an empirically grounded, psychometrically sound, and clinically operationalized method for assessing the psychological mechanisms that directly precipitate the desire for suicide. Historically, psychiatric and psychological assessments of suicide risk have relied heavily on broad indices of generalized distress, psychiatric diagnosis (e.g., major depressive disorder, bipolar disorder), subjective ratings of hopelessness, or omnibus inventories of past suicidal thoughts and behaviors. While these conventional markers identify vulnerability, they frequently demonstrate low specificity, yielding high rates of false positives and failing to elucidate the proximal, mechanistic cognitions driving an individual from diffuse psychological pain (psychache) to active, lethal suicidal ideation.

The INQ-15 bridges this critical gap by translating the theoretical tenets of the Interpersonal Theory of Suicide into an actionable, brief assessment tool. Specifically, the instrument seeks to determine:

• The presence and degree of perceived burdensomeness, distinguishing between rational perceptions of requiring assistance and distorted, fatalistic cognitive schemas wherein the respondent believes their existence drains family, friends, or society to such a severe extent that their death holds greater value than their life.
• The severity of thwarted belongingness, capturing the unmet human drive for social connectedness, interpersonal reciprocity, meaningful relational bonds, and the pervasive subjective sense of being an alienated outsider.
• The empirical interaction between these two constructs, which theoretically synergizes to convert passive death wishes (“I wish I would not wake up”) into active suicidal intent (“I want to kill myself”).

In clinical practice, the INQ-15 functions as an indispensable adjunct to standard risk assessment interviews. It allows clinicians in inpatient psychiatric facilities, outpatient psychotherapy practices, emergency departments, and crisis centers to pinpoint specific cognitive distortions amenable to evidence-based interventions, such as Cognitive Behavioral Therapy for Suicide Prevention (CBT-SP) or Dialectical Behavior Therapy (DBT). For instance, an elevated burdensomeness score signals the urgent need to challenge cognitive misattributions regarding family dynamics and self-worth, whereas an elevated thwarted belongingness score directs therapeutic focus toward behavioral activation, social skills training, and establishing supportive community connections.

In academic and clinical research contexts, the INQ-15 serves as the gold standard for testing mechanistic hypotheses in suicidology. It enables researchers to model mediation and moderation pathways between distal vulnerabilities (e.g., childhood trauma, physical illness, minority stress, unemployment) and proximal suicidal behaviors. Its brief completion time (typically 2 to 4 minutes) minimizes participant burden, making it ideal for ecological momentary assessment (EMA) protocols, repeated-measures clinical trials, and epidemiological surveys examining diverse subpopulations including veterans, sexual and gender minority individuals, and older adults.

5. Psychological Construct

The INQ-15 operationalizes two distinct yet intercorrelated psychological constructs that together form the cognitive foundation of suicidal desire within the interpersonal-psychological framework. Each subscale represents a cognitive-affective state derived from evolutionary, relational, and social-cognitive mechanisms.

Perceived Burdensomeness

Perceived burdensomeness is conceptualized as a multi-faceted cognitive misperception that one's existence constitutes an unbearable encumbrance to significant others, loved ones, community networks, or society as a whole. Crucially, suicidological theory emphasizes that perceived burdensomeness is almost invariably a cognitive distortion rather than an objective reality. Even in circumstances involving severe physical disability, chronic illness, or financial distress, the conviction that one's death would possess positive utility for others represents an erroneous, depressogenic calculation.

Within the INQ-15, perceived burdensomeness comprises two foundational dimensions:

• Belief of Incompetence and Liability: The perception that one's behaviors, emotional instability, or dependency continuously inflict harm or strain upon loved ones (e.g., Item 4: “These days I think I make things worse for the people in my life”, Item 3: “These days I think I have become a burden on society”).
• Affect of Liability / Post-Mortem Benefit: The lethal conviction that others would be objectively happier, unburdened, and better off if the individual ceased to exist (e.g., Item 1: “These days the people in my life would be better off if I were gone”, Item 2: “These days the people in my life would be happier without me”).

This construct is fundamentally distinct from generalized self-blame or low self-esteem. While low self-esteem is characterized by self-directed negative evaluations (“I am inadequate”), perceived burdensomeness entails a social-relational calculation of harm directed toward others (“My inadequacy actively damages those I love, making my continued life a moral or emotional liability”). This cognitive leap is theoretically necessary to overcome the instinctual drive for self-preservation, fostering a perverse altruistic rationalization for suicide.

Thwarted Belongingness

Thwarted belongingness is the psychologically painful, unfulfilled state resulting from an unmet need for relatedness. Drawing heavily from Baumeister and Leary's fundamental need to belong, the construct posits that human beings possess an innate evolutionary drive for frequent, non-aversive interactions with a stable framework of individuals who share mutual affective concern and reciprocal care.

Within the INQ-15, thwarted belongingness assesses the perceived absence of two vital interpersonal components:

• Loneliness and Social Alienation: The subjective experience of being emotionally detached, forgotten, or treated as an outsider during social engagements (e.g., Item 9: “These days I feel disconnected from other people”, Item 11: “These days I often feel like an outsider in social gatherings”).
• Absence of Reciprocal, Caring Bonds: The lack of reliable social support systems and intimate, trusting connections where the individual feels genuinely understood and valued (e.g., Item 12: “These days I feel like I have no one to turn to”, reversed Item 8: “These days I am fortunate to have many caring and supportive friends”, reversed Item 15: “These days I feel that there are people who really understand me”).

Importantly, thwarted belongingness is dynamic and subjectively experienced. An individual can be physically surrounded by family, colleagues, or peers and yet experience profound thwarted belongingness if they perceive an absence of genuine psychological attunement and reciprocal emotional investment. The 9 items assessing this construct include six positively phrased, reverse-scored items that evaluate intact social capital, ensuring that the scale sensitively captures varying gradations of relational integration.

6. Theoretical Framework

The INQ-15 is directly derived from the Interpersonal Theory of Suicide (IPTS), initially proposed by Thomas E. Joiner in 2005 and formally elaborated by Van Orden and colleagues in 2010. The IPTS was formulated to address a long-standing paradox in clinical suicidology: while millions of individuals experience severe emotional distress, severe major depression, and transient thoughts of death, only a small percentage attempt suicide, and an even smaller proportion die by suicide. The IPTS offers a concise, falsifiable model explaining this discrepancy through two central theoretical premises:

Premise 1: The Development of Suicidal Desire

The theory asserts that the simultaneous presence of two dynamic, malleable psychological states — perceived burdensomeness and thwarted belongingness — is both necessary and sufficient for the emergence of active suicidal desire. According to the model:

• If an individual experiences thwarted belongingness alone, they suffer profound loneliness and depressive despair, yet the evolutionary drive to protect the self typically remains intact.
• If an individual experiences perceived burdensomeness alone, they experience intense shame and guilt, but existing social connections and mutual attachments act as protective anchors preventing active lethal planning.
• However, when an individual perceives themselves as an intolerable burden to those they love and simultaneously feels entirely cut off from reciprocal human support, a sense of hopelessness regarding these interpersonal states emerges. This specific cognitive convergence engenders the belief that death is not only desirable but justifiable, giving rise to active suicidal desire.

Premise 2: The Acquired Capability for Suicide

A second foundational premise of the IPTS is that the desire for death is clinically distinct from the capability to enact lethal self-harm. Because survival instincts are biologically entrenched, individuals cannot die by suicide through desire alone; they must also possess the acquired capability for suicide. Acquired capability entails heightened physical pain tolerance and diminished fear of death, developed through habituation and opponent-process learning via repeated exposure to painful and provocative events (e.g., non-suicidal self-injury, physical abuse, combat exposure, traumatic experiences, extreme sports, or previous suicide attempts).

The INQ-15 is specifically dedicated to assessing the cognitive-affective engine of the first premise: the interpersonal desire for suicide. By precisely mapping the magnitude of perceived burdensomeness and thwarted belongingness, the INQ-15 operationalizes the proximal cognitive determinants that drive an individual toward the lethal threshold, especially when interacting with acquired capability.

7. Validity

The validity of the INQ-15 has been extensively documented across numerous independent investigations spanning general psychiatric cohorts, undergraduate students, primary care patients, veterans, and international cultural samples.

Construct and Factorial Validity

Construct validity is evidenced by the scale's clean differentiation between its two core subscales. Across multiple validation studies (e.g., Van Orden et al., 2008, 2012; Freedenthal et al., 2011), confirmatory factor analyses establish that a two-factor oblique model consistently demonstrates superior fit relative to single-factor models or orthogonal solutions. Inter-factor correlations between perceived burdensomeness and thwarted belongingness typically range between r = .35 and r = .55, confirming that while both reflect social-interpersonal distress, they capture empirically distinct psychological constructs.

Convergent Validity

The INQ-15 subscales correlate robustly and in theoretically expected directions with established measures of psychiatric distress and cognitive vulnerability:

• Perceived Burdensomeness: Exhibits strong positive correlations with the Beck Depression Inventory (BDI-II; r = .50 to .68), the Beck Hopelessness Scale (BHS; r = .45 to .62), and the shame and guilt subscales of the Test of Self-Conscious Affect (TOSCA).
• Thwarted Belongingness: Correlates strongly with the UCLA Loneliness Scale (r = .65 to .78), the Interpersonal Support Evaluation List (ISEL; negative correlations ranging from r = -.55 to -.70), and inversely with validated indices of social network size and subjective social support.

Discriminant Validity

The INQ-15 demonstrates distinct divergence from constructs that reflect non-interpersonal distress. Research indicates that the subscales correlate only weakly to moderately with generalized somatic anxiety (e.g., Beck Anxiety Inventory; r = .20 to .35) and show no meaningful association with extraneous demographic factors or socially desirable responding. Furthermore, regression models indicate that perceived burdensomeness predicts suicidal ideation even after statistically controlling for broad neuroticism, general negative affectivity, and major depressive episode severity.

Predictive and Incremental Validity

Crucially, longitudinal investigations confirm the predictive validity of the INQ-15. In prospective clinical studies, elevated baseline scores on the Perceived Burdensomeness subscale independently predict future suicide attempts and increases in suicidal ideation over 1-month, 6-month, and 1-year follow-up intervals. Furthermore, numerous hierarchical regression analyses confirm the central interaction hypothesis of the IPTS: the statistical interaction term (Perceived Burdensomeness × Thwarted Belongingness) accounts for significant incremental variance in suicidal desire and intent beyond the main effects of depression, hopelessness, history of prior attempts, and alcohol abuse.

8. Reliability

The INQ-15 possesses exemplary psychometric reliability across diverse populations, settings, and linguistic adaptations.

Internal Consistency

Internal consistency estimates, indexed by Cronbach's alpha (α) and McDonald's omega (ω), consistently surpass traditional psychometric benchmarks for both research and clinical utility (α ≥ .80):

• Perceived Burdensomeness Subscale (Items 1–6): Across original validation samples (Van Orden et al., 2012) and extensive independent replications (e.g., Hill et al., 2015; Bryan et al., 2010), Cronbach's alpha values range from α = .89 to .94, reflecting high item homogeneity and exceptional precision in measuring cognitive burden schemas. Corrected item-total correlations for these six items routinely exceed r = .70.
• Thwarted Belongingness Subscale (Items 7–15): Internal consistency estimates for the 9-item thwarted belongingness dimension consistently range from α = .84 to .89. Given that this subscale incorporates both positively worded and reverse-scored items, the robust alpha confirms strong latent coherence despite methodological variance introduced by item polarity. Corrected item-total correlations typically range from r = .50 to .75.

Test-Retest Reliability and Temporal Stability

The IPTS explicitly conceptualizes perceived burdensomeness and thwarted belongingness as dynamic, fluctuating cognitive states that are sensitive to interpersonal environmental events rather than fixed, immutable personality traits. Consequently, test-retest reliability varies logically as a function of the measurement interval:

• Over short intervals (e.g., 1 to 2 weeks) in stable outpatient cohorts, test-retest reliability coefficients demonstrate substantial stability (intraclass correlation coefficients [ICC] ranging between .78 and .86).
• Over longer durations (e.g., 3 to 6 months) or following targeted therapeutic interventions, stability coefficients decrease appropriately (.45 to .60), demonstrating the scale's sensitivity to clinical change, remission, and psychosocial remediation.

9. Factor Analysis

The structural dimensionality of the Interpersonal Needs Questionnaire was established through successive stages of exploratory factor analysis (EFA) and confirmatory factor analysis (CFA), leading from the initial 25-item experimental pool to the optimized 15-item model.

Confirmatory Factor Analysis (CFA) Fit Indices

In the definitive validation study by Van Orden et al. (2012), structural equation modeling was utilized to evaluate competitive factor structures across multiple large samples (undergraduates, military personnel, and psychiatric outpatients). The hypothesized two-factor oblique model exhibited exceptional fit indices meeting strict psychometric criteria:

• Comparative Fit Index (CFI): .95 to .98 (exceeding the standard .95 cutoff for good model fit)
• Tucker-Lewis Index (TLI): .94 to .97
• Root Mean Square Error of Approximation (RMSEA): .045 to .062 (with 90% confidence intervals below .08)
• Standardized Root Mean Square Residual (SRMR): .035 to .050

Alternative structural models, including a unidimensional (single-factor) model and orthogonal models, yielded unacceptably poor fit (e.g., CFI < .80, RMSEA > .14), providing decisive statistical justification for retaining two distinct, correlated latent factors.

Factor Loadings

Standardized factor loadings (λ) from maximum likelihood CFA robustly confirm the designated subscale allocations:

• Perceived Burdensomeness Factor: All six items (Items 1 to 6) load strongly and exclusively on this factor, with standardized loadings ranging from λ = .78 to .92 (all p < .001). Cross-loadings on the belongingness dimension are negligible (< .15).
• Thwarted Belongingness Factor: The nine items (Items 7 to 15) demonstrate standardized loadings ranging from λ = .54 to .84. Items directly assessing loneliness and social isolation (e.g., Item 9: “These days I feel disconnected from other people” and Item 11: “These days I often feel like an outsider in social gatherings”) consistently display the highest latent factor saturation (λ > .75).

10. Instrument / Measurement Tool

• Full Instrument Name: Interpersonal Needs Questionnaire – 15-Item Version (INQ-15)
• Instrument Type: Standardized self-report rating scale / psychometric questionnaire
• Administration Format: Paper-and-pencil questionnaire, computerized survey (Qualtrics, REDCap), or clinical interview rating form
• Total Number of Items: 15 items
• Subscales:
  • Perceived Burdensomeness: 6 items (Items 1, 2, 3, 4, 5, and 6)
  • Thwarted Belongingness: 9 items (Items 7, 8, 9, 10, 11, 12, 13, 14, and 15)
• Authentic Response Scale: 7-point Likert scale:
  • 1 = Not at all true for me
  • 2 = Very rarely true for me
  • 3 = Somewhat rarely true for me
  • 4 = Neutral
  • 5 = Somewhat true for me
  • 6 = Very true for me
  • 7 = Extremely true for me
• Reverse-Scoring Procedures:
  • The following six items are reverse-scored before computing subscale scores: Items 7, 8, 10, 13, 14, and 15.
  • Reverse Scoring Formula: Transformed Score = 8 − Original Response (e.g., a raw score of 7 becomes 1; a raw score of 1 becomes 7).
• Scoring and Indexing:
  • Subscale Sum Method: Perceived Burdensomeness score ranges from 6 to 42. Thwarted Belongingness score ranges from 9 to 63. Higher aggregate scores indicate greater interpersonal distress.
  • Subscale Mean Method: Item scores within each subscale are averaged (sum of items divided by number of items), yielding a composite metric ranging from 1.00 to 7.00 for each dimension.
  • Total Score: Although individual subscale scores should always be examined separately to preserve theoretical specificity, an omnibus total score can be calculated (range: 15 to 105).
• Target Population: Adolescents, university students, working adults, military service members, and geriatric clinical and community populations.
• Average Completion Time: Approximately 2 to 4 minutes.

11. Permissions & Fee and Test Year

• Year of Formal Publication: 2008 (Initial validation in Journal of Consulting and Clinical Psychology; comprehensive multi-sample refinement published in 2012 in Psychological Assessment).
• Copyright & Intellectual Ownership: Kimberly A. Van Orden, Tracy K. Witte, Kathryn H. Gordon, Thomas W. Bender, and Thomas E. Joiner, Jr.
• Usage Permissions & Fees: The INQ-15 is an open-access psychometric instrument made freely available for academic research, non-commercial psychological investigations, and individual clinical assessment purposes without licensing fees. Formal written permission is generally not required for non-profit academic research, provided that appropriate scholarly attribution and citation are given. Commercial redistribution, inclusion in fee-for-service proprietary software platforms, or third-party digital health applications requires formal authorization from the copyright holders.

12. References

Bryan, C. J., Morrow, C. E., Anestis, M. D., & Joiner, T. E. (2010). A test of the interpersonal-psychological theory of suicidal behavior in a military sample. Journal of Clinical Psychology, 66(1), 19–30. https://doi.org/10.1002/jclp.20627

Freedenthal, S., Lamis, D. A., Crosby, A. E., & Milan, S. (2011). Evaluation of the Interpersonal Needs Questionnaire with college students. Journal of Clinical Psychology, 67(6), 617–623. https://doi.org/10.1002/jclp.20786

Hill, R. M., Rey, Y., Marin, C. E., Sharp, C., Green, K. L., & Pettit, J. W. (2015). Evaluating the Interpersonal Needs Questionnaire: Comparison of the 15-item and 12-item versions. Suicide and Life-Threatening Behavior, 45(6), 682–694. https://doi.org/10.1111/sltb.12160

Joiner, T. E. (2005). Why people die by suicide. Harvard University Press. https://www.hup.harvard.edu/books/9780674025493

Van Orden, K. A., Cukrowicz, K. C., Witte, T. K., & Joiner, T. E. (2012). Thwarted belongingness and perceived burdensomeness: Construct validity and psychometric properties of the Interpersonal Needs Questionnaire. Psychological Assessment, 24(1), 197–215. https://doi.org/10.1037/a0025358

Van Orden, K. A., Witte, T. K., Cukrowicz, K. C., Braithwaite, S. R., Selby, E. A., & Joiner, T. E. (2010). The interpersonal theory of suicide. Psychological Review, 117(2), 575–600. https://doi.org/10.1037/a0018697

Van Orden, K. A., Witte, T. K., Gordon, K. H., Bender, T. W., & Joiner, T. E. (2008). Suicidal desire and the capability for suicide: Tests of the interpersonal-psychological theory of suicidal behavior. Journal of Consulting and Clinical Psychology, 76(1), 72–83. https://doi.org/10.1037/0022-006X.76.1.72

13. Items of the Scale