Abstract
The capacity of the Young Schema Questionnaire (YSQ) to predict psychopathology in specific clinical groups has consistently produced mixed findings. This study assessed three versions of the Young Schema Questionnaire (YSQ), including the long form (YSQ-L3), short form (YSQ-S3), and the recent Rasch-derived version, the YSQ-R, and their subscales, in predicting psychological distress in three different psychiatric groups and a non-clinical group. Test equating techniques were first applied to derive a common metric to ensure that each YSQ version was directly comparable. In the second stage, multiple regression analyses were employed to assess the predictive validity of each YSQ version and their subscales. The YSQ-R and YQ-L3 and their respective subscales were similar in their predictive power across all groups and conditions. The YSQ-S3 could not predict pre-treatment Early Maladaptive Schemas (EMS) and global symptom severity in the PTSD group, nor could it predict pre-treatment EMS and changes in global symptom severity in the Alcohol and Substance Use group. This was the first study to assess the predictive validity of three different versions of the YSQ. Our findings suggest that YSQ-R has the breadth of the YSQ-L3 and the shortness of the YSQ-S3, making it an ideal tool for assessing EMS across research and clinical settings.