Development and Preliminary Validation of the Mentalizing Vignettes Task: A Measure of Mentalizing Across Relational Contexts.

Mentalizing is a potentially transdiagnostic construct with important implications for the emotional and interpersonal functioning of individuals with mental health vulnerabilities. The multidimensional and dynamic qualities of mentalizing warrant clinically and contextually relevant assessment grounded in diverse interpersonal situations. We developed the Mentalizing Vignettes Task (MVT), a vignette-based, multiple-choice measure of mentalizing across various relationship domains (e.g., friendship, family, romantic). Study 1 focused on the development, content validation, and item analysis of the MVT-30 with a community sample (n = 120), resulting in a refined 24-item version (MVT-24). Study 2 assessed the internal consistency, convergent validity, known-groups validity, and concurrent validity of the MVT-24 against other measures of mentalizing and related constructs across three groups: borderline personality disorder (n = 37), somatoform disorder (n = 40), and community controls (n = 37). The measure demonstrated adequate internal consistency (Cronbach's alpha = 0.80) and content validity (Scale-CVI = 0.98) with preliminary evidence of convergent and concurrent validity through expected associations with uncertainty in reflective functioning, self-mentalizing, processing emotions, attachment anxiety, and interpersonal functioning. MVT-24 also differentiated the clinical groups from the control, supporting its known-groups validity (Cohen's d = 1.12). The current study introduces a brief, context-sensitive tool for assessing mentalizing, with promising implications for clinical formulation and intervention.