Schema Therapy (ST) proposes that psychological problems arise from unmet core emotional needs, expressed through early maladaptive schemas (EMS) grouped into broader schema domains. The five original domains are Disconnection and Rejection, Impaired Autonomy and Performance, Impaired Limits, Other-Directedness, and Overvigilance and Inhibition. However, empirical research on the structure of schema domains has been inconsistent, with studies identifying between two and five domains and varying schema groupings. To refine the model, Arntz et al. (2021) proposed adding a sixth core need, self-coherence, and two associated schemas: Incoherent Identity and Incomprehensible World.

The Young Schema Questionnaire (YSQ) is the most widely used instrument for assessing EMS in research and clinical practice. To incorporate the revisions proposed by Arntz et al., the YSQ-4 was developed as an experimental extension of the YSQ-3. It aims to measure 22 schemas, including the newly proposed constructs, using a refined item set. This study psychometrically assessed the YSQ-4 in a diverse clinical and non-clinical sample (N = 501) by evaluating its internal consistency and exploring its domain structure and schema groupings, with special attention to the organization of the two new schemas.

At least adequate internal consistency was found for all schema subscales, indicating that they reliably measured the intended constructs. Exploratory factor analyses revealed a five-factor model with outliers included and a four-factor model without outliers. The four-factor model was more interpretable and better aligned with previous research. The new schemas clustered within a Disconnection related domain but did not form a separate Incoherent Self domain. Additionally, Incoherent Identity cross-loaded on an Impaired Autonomy related domain, suggesting that self-coherence may overlap with both attachment and autonomy related needs rather than representing a distinct need.

Beyond providing preliminary psychometric support for the YSQ-4, this study highlighted persistent methodological issues in schema domain research. Problems included inconsistent application of best practices in factor analysis, such as inappropriate extraction and rotation methods and weak criteria for interpreting factor loadings. Suggestions for improving methodological rigor are discussed. Overall, this study contributes to the schema domain literature by empirically testing theoretical reformulations and proposing directions for future exploratory and confirmatory research.