Preliminary Psychometric Properties of Panic Disorder Severity Scale—Self‐Report Version: Validity, Reliability, and the Cut‐Off Point in Persian Clinical Samples

INTRODUCTION: Accurate assessment of panic disorder (PD) severity requires brief and psychometrically sound instruments. The Panic Disorder Severity Scale-Self-Report (PDSS-SR) is widely used for this purpose. The present study aimed to evaluate the validity, reliability, and optimal cut-off point of the PDSS-SR in an Iranian sample. METHOD: Following a descriptive design, the clinical group of the sample consisted of 45 clinical patients diagnosed with PD (75.6% female), with a mean age of 34.04 years (standard deviation [SD] = 12.17) in Tehran in 2023 and 2024 referred to psychotherapy clinics, along with 18 non-PD individuals for the comparison group (83.3% female), with an average age of 31.17 (SD = 7.94). Data were analyzed using confirmatory factor analysis, correlation matrices, reliability coefficients, receiver operating characteristic (ROC) curves, sensitivity, specificity, and the estimation of cut-off points. RESULTS: The construct validity of the PDSS-SR was confirmed through CFA, with adequate goodness-of-fit for the PDSS-SR single-factor structure. By calculating the correlation of PDSS-SR scores with scores on anxiety-related scales, convergent validity was obtained on average. The sensitivity and specificity obtained from the PDSS-SR identified the optimal cut-off point of 6.500 (area under curve [AUC] = 0.78), with sensitivity (90.70%) and specificity (61.11%) based on the Youden index. Reliability was obtained by calculating Cronbach's alpha, McDonald's omega, test-retest correlation coefficient, and intraclass correlation coefficient (ICC) as 0.864, 0.861, 0.716, and 0.864, respectively. CONCLUSION: This research found that the PDSS-SR had sufficient reliability, moderate convergent validity, and good construct validity in Iranian samples, with an optimal cut-off point of 6.50. Therefore, it can be applied in clinical settings.