Psychometric Properties of the Dichotomous Thinking in Eating Disorders Scale (DTEDS)

Introduction: The Dichotomous Thinking in Eating Disorders Scale (DTEDS) is a short, self- assessment of the presence of a rigid, “black-and-white” cognitive thinking style. This study aimed to examine the psychometric properties of Dichotomous Thinking in eating disorders in Iran.Methods: For this purpose, a sample of 362 women with nutritional problems referring to health centers, nutrition clinics, and beauty institutes of Shiraz (2019-2020) were selected by convenience sampling method and Eating Attitudes Scale. In this descriptive and cross-sectional study, participants responded to the Persian version of Dichotomous Thinking Eating Disorders and Positive and Negative Perfectionism Scales. Finally, based on the data collected, exploratory and confirmatory factor analysis, convergent and divergent validity were employed to determine the construct validity. Moreover, the reliability of the questionnaire was assessed via internal consistency (Cronbach alpha).Results: factor analysis supported the original two-factor model of the questionnaire, and fit indices indicated a good model fit. The questionnaire's convergent and divergent validity and internal consistency were also adequate. For two factors, Cronbach’s alpha ranges from 0.74 to 0.88, suggesting satisfactory reliability of the Persian version of the DTEDS.Conclusion: The Persian version of the DTEDS has adequate validity and reliability in Iranian society and is a good self-report for research and clinical settings