Psychometric Evaluation and Evidence of Validity and Reliability of the Turkish Versions of the International Depression Questionnaire and the International Anxiety Questionnaire

Objective: Depression and anxiety are among the most prevalent mental health disorders worldwide, yet existing diagnostic tools do not always align with contemporary classification systems such as the International Classification of Diseases‐11(ICD‐11). The study aimed to evaluate the validity and reliability of the International Depression Questionnaire (IDQ) and the International Anxiety Questionnaire (IAQ) in the Turkish population. Methods: The primary objectives were to assess the psychometric properties of these new health assessment tools, the only based on the ICD‐11, in a culturally diverse setting. Participants were recruited through online survey platforms and university announcements, ensuring a diverse representation of the Turkish adult population. The sample consisted of 2894 individuals(1097 male, 1797 female) aged 18–65, including university students, and community members from various socio economic backgrounds. Results: Factor analysis revealed that the IDQ and IAQ maintained their original factor structures, supporting their construct validity. The internal consistency of both the IDQ and IAQ was high, with Cronbach's α coefficients exceeding the threshold of0.70, indicating acceptable reliability. These tools can be confidently used in both clinical and research settings, facilitating better mental health assessment and intervention strategies in Turkey. Conclusion: The findings suggest that the Turkish versions of the IDQ and the are valid and reliable tools for assessing the severity of depression and anxiety symptoms in Turkish adults. These instruments can support both clinical and research efforts by facilitating early identification of individuals who may benefit from further psychological evaluation