BACKGROUND: The immense comorbidity among disorders could be ascribed to common trans-diagnostic processes. The term trans-diagnostic has been of interest in both pathology and psychology. Trans-diagnostic treatments were created as opposed to treatments based on single-diagnosis treatments. It addresses the common underlying mechanisms in a range of comorbid disorders. Trans-diagnostic treatment is one of the new psychological treatments, and its efficacy has been proven on many psychological variables. The main focus of the current study is on designing unified trans-diagnostic interventions and their efficacy on the shared mechanisms of comorbid obsessive personality disorder with anxiety, depression, and obsessive-compulsive disorder. MATERIALS AND METHODS: the sequential transformative strategy has two stages; qualitative and quantitative. In The first and qualitative section of the research, explanatory research will be carried out to investigate the trans-diagnostic intervention using a systematic review. To validate the trans-diagnostic intervention, and simultaneously with the trans-diagnostic intervention, a questionnaire has been prepared and given to 10 psychology experts and professionals in the treatment field concerning content validity by evaluators. CONCLUSION: Designing unified trans-diagnosis interventions and their efficacy on the common mechanisms of comorbid obsessive personality disorder with anxiety, depression, and obsessive-compulsive disorder is an effective treatment method for helping those suffering from a personality disorder. Clinical psychologists, psychology experts, psychiatrists, and mental health experts are all the immediate beneficiaries of this study. Moreover, clients could benefit from this intervention with less money and time.

Introduction:This study aimed at determining the causal relationship of metacognitive beliefs as a mediator between one of early maladaptive schemas including (emotional deprivation, abandonment, mistrust/abuse, social isolation/alienation and defectiveness/shame) and borderline and antisocial personality patterns.Materials and Methods:The study type has been relational and seeking causal modeling of path analysis has been used. The population used in this study included outpatients in counseling, psychological and psychiatric centers in 2012–2013. We randomly distributed 350 questionnaires in five centers out of three parts in Isfahan, and finally 230 valid questionnaires were evaluated and analyzed. Data collection tool has been Millon Clinical Multiaxial Inventory-III's (MCMI-III's) personality questionnaire, Yang's schema questionnaire (75 items), Metacognition Questionnaire-30 (30 items). Reliability of the Yang's Schema Questionnaire in this study was calculated by Cronbach's alpha (α =96%), and that of metacognition was calculated the same way (α =87%). Data analysis has been done using MCMI-III's software for Millon's personality questionnaire, and SPSS-16 and AMOS-18 software. We used path analysis method for testing each model in statistical data analysis.Result:The results of this study suggest a possible causal relationship between the number of one of the early maladaptive schemas and the patterns of anti-social and borderline personalities through some metacognitive beliefs.Conclusion:This study showed that cognitive beliefs can be activators of the early schema and continuation's coping behaviors in personality patterns.