Tehran University of Medical Sciences Iranian Journal of Psychiatry 1735-4587 1 4 2006 12 15 169 171 Yaghoob Vakili Iran University of Medical Sciences Ladan Fata Iran University of Medical Sciences, Tehran Psychiatry institute 2015 10 17 Objective: The aim of this study is to evaluate the effectiveness of the metacognitive model in treating post-traumatic stress disorder. Method: In a single-subject experimental trial of multiple baseline type, the treatment process was carried out on an 18-year-old male subject. The patient satisfied the DSM-IV criteria for PTSD and was assessed for pre-duration and post treatment. The scales used in this study included: Impact Event Scale-Revised (IES-R), Beck Depression Inventory (BDI-II), Beck anxiety Inventory (BAI), and Subjective Units Distress Scale (SUDs). In addition, all scales were again completed by the subject at 1-month, 3- month, and 6- month follow-ups. Results: The treatment led to reductions in symptoms of PTSD, anxiety, depression and distress. Gains were maintained at follow-ups. Conclusion: The treatment approach which is based on the metacognitive model, appears to be effective in the treatment of post-traumatic stress disorder. https://ijps.tums.ac.ir/index.php/ijps/article/view/427 https://ijps.tums.ac.ir/index.php/ijps/article/download/427/423