Mehdi Rabiei - Assistant Professor, Department of Clinical Psychology, School of Medicine, Baqiyatallah University of Medical Sciences, Tehran, Iran
Masoud Nikfarjam - Assistant Professor, Department of Psychology, School of Medicine, Shahrekord University of Medical Sciences, Shahrekord, Iran
Nezamodin Ghasemi - PhD Student, Department of Psychology, School of Education and Psychology, University of Isfahan, Isfahan, Iran
Kazem Khorramdel - PhD Student, Department of Psychology, School of Psychology, University of Mohaghegh Ardabili, Ardabil, Iran

Background & Aims: Trichotillomania (TTM) is an unknown disorder and resistant to treatment. The purpose of this study was to develop and validate the new metacognitive-cognitive-behavioral model for trichotillomania. Methods: The present study was a description and correlation study. In this study, ۶۳۵ participants (۳۰۴ male and ۳۳۱ female) were selected. The participants completed the Massachusetts general hospital hair pulling scale (MGH-HPS), dysfunctional attitude scale (DAS), cognitive distortion scale (CDS), automatic thought questionnaire (ATQ), metacognition questionnaire (MCQ), and the obsessive-compulsive behavior scale (OCBS). For reliability assessment of the factor structure of the metacognitive-cognitive-behavioral model, the structural equation modeling analysis was used by AMOS software. Results: The results of the structural equation modeling supported a metacognitive-cognitive-behavioral model for trichotillomania. Moreover, the results showed that the model had the best fit to the data and was closely related to the theoretical assumptions. Conclusion: The model presented in this study illustrates a multidimensional approach that focuses on the metacognitive, cognitive, and behavioral dimensions; hence, the model presented in this study is a new explanatory model. This model may prompt future research into trichotillomania and facilitate clinical treatment and case formulation

Modeling, Trichotillomania, Behavior, cognition, metacognition