Amin Khaje Mansoori - Department of School Psychology, Faculty of Psychology and Education, University of Tehran, Tehran, Iran.
Parvaneh Mohammadkhani - Department of Clinical Psychology, University of Social Welfare and Rehabilitation Sciences, Tehran, Iran.
Mahdi Mazidi - Department of Clinical Psychology, University of Social Welfare and Rehabilitation Sciences, Tehran, Iran.
Maryam Kami - Department of Clinical Psychology, University of Social Welfare and Rehabilitation Sciences, Tehran, Iran.
Mojgan Bakhshi Nodooshan - Department of Clinical Psychology, Faculty of Humanities, Yazd Branch, Islamic Azad University, Yazd, Iran.
Shokooh Shahidi - Department of Clinical Psychology, Faculty of Medicine, Kashan University of Medical Science, Kashan, Iran.

Objective:This study aimed to differentiate illness anxiety and generalized anxiety by the role of metacognition and intolerance of uncertainty. Methods: This research was a descriptive-correlational study with an ex post facto design. The study population included all students of Yazd University, and the study sample comprised ۴۰۰ healthy adult university students (Mean age=۲۳.۳ years, SD=۴.۹) who were selected using the convenience sampling method. Participants were asked to fill out ۴ self-report measures: short health anxiety inventory, intolerance of uncertainty scale, metacognitions questionnaire, and Penn State Worry questionnaire. Finally, ۳۳۸ questionnaires were statistically analyzed by SPSS ۲۰, using ANOVA and discriminant function analysis. Results: The results showed that there were significant differences between different groups with respect to most studied variables and that intolerance of uncertainty cannot discriminate between ۲ disorders. We can argue that this factor is a significant risk factor in both illness anxiety and generalized anxiety disorders. Conclusion: In general, transdiagnostic factors such as intolerance of uncertainty and cognitive beliefs have significant roles in emotional disorders, and can be considered as therapeutic targets.

Metacognition, Comorbidity, Anxiety disorders, Diagnosis