Comparison of the effectiveness of schema therapy and acceptance and commitment therapy on perfectionism in patients with obsessive-compulsive personality disorder

In the last two decades, attention to perfectionism has been increased. Perfectionism is one of the main symptoms of patients with obsessive-compulsive personality disorder. The aim of this study was comparison of the effectiveness of schema therapy and acceptance and commitment therapy on perfectionism in patients with obsessive-compulsive personality disorder.   

The research method in this study was quasi–experimental design and pretest-posttest-followup with experimental groups and a control group. The statistical population included all patients with obsessive-compulsive personality disorder referred to psychological and counseling services centers in Tehran in the year 2021. Among them, 51 patients with obsessive-compulsive personality disorder were selected based on entry and exit criteria and by available sampling method and randomly were placed into three groups (17 people) of schema therapy, acceptance and commitment therapy and control group. The first experimental group received the schema therapy with Young's approach (1990) in 8 sessions of 90 minutes, the second experimental group received the acceptance and commitment therapy with Hayes, Strosahl, and Wilson of approach (1999) in 8 sessions of 90 minutes and the control group was in the waiting list. The research instruments included the Perfectionism Inventory (PI) and Millon Clinical Multiaxial Inventory (MCMI-III). The obtained data were analyzed using repeated measure of covariance analysis (mixed design) and Bonferroni post hoc test and SPSS25 software.     

The findings showed that there was a significant difference between the experimental groups and control group; Both schema therapy and acceptance and commitment therapy interventions had a positive effect on perfectionism in patients with obsessive-compulsive personality disorder and the effect of these therapeutic interventions in the follow-up phase has been stable (P <0.05). Also, the results of Bonferroni post hoc test showed that the the effectiveness of schema therapy intervention on perfectionism was higher than acceptance and commitment therapy (P <0.05).  

According to the research findings, it can be concluded that schema therapy and acceptance and commitment therapy interventions can be effective in improving perfectionism of patients with obsessive-compulsive personality disorder; It is recommended that therapists and counselors use these therapies for improving the perfectionism of patients with obsessive-compulsive personality disorder.