Background and aims: With attention to considered various cognitive factors in psychopathology of obsessive- compulsive disorder, generalized anxiety disorder, the aim of this study was comparison of Thought Action Fusion (TAF), responsibility and the overestimation of threat (RT), and over importance and Control Thoughts (ICT), Perfectionism and The Intolerance of Uncertainty (PC) cognitive beliefs in Obsessive- Compulsive Disorder (OCD), Generalized Anxiety Disorder (GAD), Major Depression Disorder (MDD) and normal group to more clarification psychopathology of these disorders.

Methods: This study is causal-comparative research. The clinical samples include patients referred from January to June 2016 to Sari Shahid Zareh hospital in this regard. From each of these groups, 30 individuals were selected from hospitals and clinics of Sari and 30 individuals were selected accomplish obsessive beliefs questionnaire and thought action fusion scale. Data were analyzed by MANOVA.

Results: The results of MANOVA and Tukey posthoc test showed that OCD group was significantly higher than other groups in TAF, RT and ICT (P<0.001), but in PC didn’t show significantly difference between OCD and GAD groups (P>0.086). Also, the results showed that all of these cognitive beliefs OCD and GAD groups were significantly higher than depression and normal groups (P<0.001).

Conclusion: According to these results, it seems that TAF, RT and ICT are more specific for OCD, but about PC there isn’t this specialty and it is common cognitive vulnerability in OCD and GAD.