Tehran University of Medical Sciences Iranian Journal of Psychiatry 1735-4587 19 1 2023 12 16 30 44 Mohammadreza Davoudi Department of Clinical Psychology, University of Social Welfare and Rehabilitation Sciences, Tehran, Iran Abbbas Pourshahbaz Department of Clinical Psychology, University of Social Welfare and Rehabilitation Sciences, Tehran, Iran. Behrooz Dolatshahi Department of Clinical Psychology, University of Social Welfare and Rehabilitation Sciences, Tehran, Iran Ali Nazeri Astaneh Psychosis Research Center, University of Social Welfare and Rehabilitation Sciences, Tehran, Iran 2022 12 13 2023 05 06 Objective: Obsessive-Compulsive Disorder (OCD) has been considered a heterogeneous psychiatric disorder. Identifying this heterogeneity can lead to better diagnosis and treatment. The two most common OCD subtypes include contamination/cleaning and danger/checking. This study aimed to identify the network structure of OCD symptoms, personality, and obsessive beliefs in these OCD subtypes. Method: 333 patients with OCD were included in the study (156 patients with the danger/check subtype and 177 patients with the contamination/cleaning subtype). In addition, 276 healthy individuals participated in this study. We used a network analysis approach to determine the OCD central symptoms [nodes]. The Personality Beliefs Questionnaire-Short Form [PBQ-SF], Obsessive-Compulsive Inventory-Revised [OCI-R], and Obsessional Beliefs Questionnaire-44 [OBQ-44] were used for network estimation. Results: The results indicated that the network structure in healthy individuals was different from the network structure in patients with obsessive-compulsive disorder [PwOCD]. In healthy individuals, "obsessive” personality belief and “danger” obsessive belief were the most strength nodes and formed the core of the central communication between symptoms in these subjects. Regarding the contamination/cleaning subtype, the most central symptoms include "washing" obsessive symptom, “danger” obsessive belief, and "wash" obsessive symptom. However, "perfect" obsessive beliefs, "check" obsessive symptoms, and “avoidant” personality beliefs were the most central symptoms in the danger/check subtype. These results demonstrated that each of the studied groups had a unique network structure, which is consistent with the heterogeneous nature of OCD. Conclusion: Different OCD subtypes have different cognitive-behavioral network structures. According to the results of this study, these symptoms should be given priority in OCD theoretical models and treatment strategies. https://ijps.tums.ac.ir/index.php/ijps/article/view/3459