ABSTRACT
Abstract Introduction: Repetitive thinking as a transdiagnostic factor plays an essential role in the development and maintenance of emotional disorders. Two versions of the Repetitive Thinking Questionnaire (RTQ-31 and RTQ-10) are the best-known measures used for assessing repetitive thinking in clinical and non-clinical samples. The present study was conducted to evaluate the psychometric properties and factor structure of Persian versions of them. Methods: Participants were 592 students assessed with the RTQ-31, the RTQ-10, the Ruminative Response Scale, the Perseverative Thinking Questionnaire, the Beck Depression Inventory-second edition, the Beck Anxiety Inventory, and the Depression, Anxiety, Stress Scale-21. Exploratory and confirmatory factor analysis were used to determine construct validity. Results: The findings showed that the RTQ-31 and the RTQ-10 demonstrated excellent internal consistency and good test-retest reliability (α = 0.946: r = 0.844) and (α = 0.903: r = 0.776) respectively. Also, five items from the original version were omitted due to inadequate factor loadings. This study showed that the resulting 26-item version has a two-factor structure, while the short version has a one-dimensional structure. Finally, it was found that repetitive thinking has a positive and powerful relationship with other measures of rumination and with symptoms of depression, anxiety, and stress. Conclusion: Persian versions of the RTQ have good factor structures and psychometric properties and can be used in clinical populations and related studies.