Reliability and Validity of the International Depression Questionnaire and International Anxiety Questionnaire in English- and Spanish-Speaking Samples in Chile, Mexico, and the United States

Given the high prevalence of depressive disorder and generalized anxiety disorder (GAD) globally and their comorbidity, it is imperative to have reliable and valid measures of these constructs. The International Depression Questionnaire (IDQ) and International Anxiety Questionnaire (IAQ) are recently developed measures to assess for depressive disorder and GAD, respectively, based on ICD-11 criteria. The current study examined the reliability and validity of the IDQ and IAQ in English- and Spanish-language translations in four samples from Chile, Mexico, and the United States. The Spanish IDQ and IAQ demonstrated good to excellent internal consistency (IDQ omega = .87-.91 and IAQ omega = .86-.93) and strong convergent validity. Overall prevalence for ICD-11 depressive disorder was 15.3%, and the GAD prevalence was 22.4% across samples. Confirmatory factor analyses (CFA) found good to excellent fit across the four samples, supporting the unidimensionality of the IDQ and IAQ. Results indicate the Spanish translations of the IDQ and IAQ are psychometrically sound and appear appropriate for use in North and South American samples of Spanish speakers. Results also supported the psychometric properties of the English IDQ and IAQ in the United States.