The International Anxiety Questionnaire (IAQ)
A Self-Report Measure of ICD-11 Generalized Anxiety Disorder
The International Anxiety Questionnaire (IAQ) is a self-report measure of ICD-11 Generalised Anxiety Disorder (ICD-11 diagnostic code 6B00). It can be used to generate severity scores and to identify cases meeting diagnostic criteria. The severity scoring method simply involves summing the scores of the 8 IAQ items producing a possible range of scores from 0 to 32. No cut-off scores are proposed, as ‘caseness’ is defined by applying the ICD-11 diagnostic algorithm. The IAQ is freely available in the public domain to all interested parties. The development and initial validation study can be found by clicking here.
A copy of the IAQ can be freely downloaded by clicking on the version below. The document includes a description of the scale, the key publications, and the scoring instructions. Translations are in process. If you wish to contribute a translation, please get in touch with Prof. Mark Shevlin by email at email@example.com
Key publications are:
Shevlin, M., Hyland, P., Butter, S., McBride, O., Hartman, T. K., Karatzias, T., & Bentall, R. P. (2023). The development and initial validation of self-report measures of ICD-11 depressive episode and generalized anxiety disorder: The International Depression Questionnaire (IDQ) and the International Anxiety Questionnaire (IAQ). Journal of Clinical Psychology, 79(3), 854–870. https://doi.org/10.1002/jclp.23446
Hyland, P., Redican, E., Karatzias, T., & Shevlin, M. (2023, in press). Assessing the validity and reliability of the International Anxiety Questionnaire and the International Depression Questionnaire in two bereaved national samples. Clinical Psychology & Psychotherapy.