The Young Schema Questionnaire (YSQ) is the primary instrument used in Schema Therapy to measure the presence of Early Maladaptive Schemas (EMSs). A new experimental version was developed based on a reformulated theory, the YSQ-4. Three new EMSs were added (Incomprehensible World, Incoherent Identity, and Unfairness), and two EMSs were split into four (Emotional Constriction, Fear of Losing Control, Internal Punitiveness and External Punitiveness), resulting in a 23-schema structure. 

The present study is the first to investigate the psychometric properties of the YSQ-4 in a large, multicultural sample of clinical and non-clinical participants (N = 3,801, 41% clinical). Internal consistency, unidimensionality, factor structure, and discriminant validity were examined using Cronbach's alpha, confirmatory factor analysis (CFA), and independent samples t-tests. The data showed good internal consistency with all 23 scales demonstrating acceptable to excellent internal consistency (Cronbach’s alpha values ranging from .71 to .94). 

Unidimensionality findings were mixed; most scales showed adequate fit, while some scales showed item redundancy, and Unfairness showed signs of multidimensionality and was thus split into two EMSs for the subsequent analyses. The hypothesized 24-factor structure received overall good support from CFA, although conceptual proximity between some schemas was observed. Finally, the clinical group scored significantly higher than the non-clinical group on all schemas, supporting the discriminant validity of the YSQ-4. These findings provide preliminary psychometric support for the YSQ-4 and suggest that incorporating the newly proposed EMSs may enhance the assessment and treatment of psychopathology within a Schema Therapy framework.