Investigating the Psychometric Properties of the Persian Version of the International Adjustment Disorder Questionnaire Among University Students in Tehran City, Iran

Objectives This study aimed to assess the psychometric properties of the Persian version of the international adjustment disorder questionnaire (IADQ), including reliability, validity, and confirmatory factor analysis (CFA) in a university student population. Methods Using convenience sampling, this cross-sectional study was conducted on 495 university students aged 18 to 50 in Tehran City, Iran. Data were collected via a paper-and-pencil method in Tehran universities between January 10, 2024 and March 12, 2024, with participants completing the IADQ, international depression questionnaire (IDQ), international trauma questionnaire (ITQ), prolonged grief-13-revised (PG-13-R), and international anxiety questionnaire (IAQ) questionnaires after providing informed consent. Data were analyzed using SPSS software, version 26 and Mplus software, version 8.3.2. The factor structure of the IADQ was examined through CFA using the maximum likelihood ratio (MLR) and the weighted least squares mean and variance adjusted (WLSMV) method; model fit was evaluated using standard indices including the comparative fit index (CFI), Tucker-Lewis index (TLI), root mean square error of approximation (RMSEA), and standardized root mean square residual (SRMR). Convergent and discriminant validity were assessed through correlations with other questionnaires, and reliability was evaluated using the Cronbach α, McDonald’s omega, the mean inter-item correlation (MIIC), and test, re-test reliability via the intraclass correlation coefficient (ICC). Results The omega coefficient for the overall scale was 0.94. This scale demonstrated significant positive correlations with the IDQ (0.49), PG13R (0.59), and IAQ (0.64). Additionally, weak correlations were reported between the IADQ scale and post-traumatic stress disorder (PTSD) (0.14) and complex post-traumatic stress disorder (CPTSD) (0.09). Conclusion Overall, the findings suggest that the Persian version of IADQ has adequate validity and reliability in a student population.