Abstract
The present study aimed to investigate the psychometric properties, factor structure, and optimal cutoff score of the Psychological Distress Questionnaire (DQ5) among Iranian adolescents. A descriptive-correlational research design was adopted, and the sample consisted of 462 students from middle and high schools in Hamedan, selected using a convenience sampling method. Participants responded to the DQ5, the Kutcher Adolescent Depression Scale, the Social Anxiety Scale for Adolescents, and Ryff’s Psychological Well-Being Questionnaire. To evaluate the reliability of the DQ5, both test-retest and internal consistency methods were used. A subgroup of 25 students completed the questionnaire again after seven days, yielding a test-retest correlation of 0.86 for the distress component, confirming strong temporal reliability. Cronbach’s alpha was calculated at 0.81, indicating acceptable internal consistency. Construct validity was supported by significant item-total correlations. Content validity was confirmed both qualitatively and quantitatively; all items achieved CVR values above 0.80 and CVI values exceeding 0.90. Convergent validity was assessed through correlations between psychological distress and related constructs: depression (r = 0.27), anxiety (r = 0.25), and psychological well-being (r = –0.33), supporting the scale’s convergent validity. Confirmatory factor analysis revealed that the DQ5 is best represented by a unidimensional model. Furthermore, ROC curve analysis identified a cutoff score of 13.5 as optimal, with a sensitivity of 92% and specificity of 96%. These findings suggest that the DQ5 is a valid and reliable tool for identifying psychological distress in Iranian adolescents and may serve as a practical instrument for early detection and intervention in educational and mental health settings.