Background: Obsessive Beliefs Questionnaire (OBQ) is a valid measure for assessing obsessional beliefs, which are the main symptoms of obsessive-compulsive disorder (OCD). It is translated and assessed psychometric properties in many languages, however, no valid questionnaire for assessing the beliefs related to OCD is established in Thailand.

Objective: To assess the psychometric properties of the Thai version of the Obsessive Belief Questionnaire (OBQ-T).

Materials and Methods: Participants include ninety-two OCD patients who were duly informed of the details of the present study. Written consent was obtained. The Obsessive Beliefs Questionnaire-44 (OBQ-44) was translated into Thai (OBQ-T) after receiving permission. Data regarding the characteristics of the participants, the OBQ-T, the Thai self-report version of the Yale-Brown Obsessive-Compulsive Scale-Second Edition (Y-BOCS-II-SR-T) severity scale, the Thai Florida Obsessive Compulsive Inventory (FOCI-T), the Patient Health Questionnaire (PHQ-9), and the Pictorial Thai Quality of Life (PTQL), were collected and analyzed. Psychometric properties of the OBQ-T were tested.

Results: The OBQ-T has excellent reliability with a Cronbach’s coefficient of 0.945. It has a positive correlation with the Y-BOCS II-SR-T severity scale and the FOCI, which indicates the concurrent validity of the OBQ-T. The content validity index shows acceptable content validity. The confirmatory factor analysis (CFA) and the exploratory factor analysis (EFA) were examined, and the three-factor model is most similar to the original OBQ-44, which is composed of three factors reflecting responsibility and threat estimation, perfectionism and intolerance for uncertainty, and importance and control of thought.

Conclusion: The OBQ-T has an acceptable reliability and validity for the measurement of beliefs and appraisals, which are related to the pathogenesis of obsessions.

Received 25 October 2023 | Revised 29 January 2024 | Accepted 5 February 2024

DOI: 10.35755/jmedassocthai.2024.3.13951