The International Trauma Questionnaire (ITQ) is a brief measure used to identify possible PTSD and CPTSD [499] as defined by ICD-11. An indicative diagnosis of PTSD requires that a person must endorse having experienced at least one symptom from each of the three core symptom clusters (re-experiencing in the here and now, avoidance, or sense of current threat) as ‘moderately’, ‘quite a bit’, or ‘extremely’ in the past month, as well as functional impairment associated with these symptoms. An indicative diagnosis of CPTSD requires that in addition to meeting criteria for a diagnosis of PTSD, a person must endorse having experienced at least one symptom from each of the three disturbances in self-organisation clusters (affective dysregulation, negative self-concept, disturbances in relationships). A person can receive an indicative diagnosis of either PTSD or CPTSD – not both (i.e., if criteria for CPTSD is met, the person does not also receive an indicative diagnosis of PTSD [499]). At the time of writing, no studies have been conducted to validate the ITQ as a measure of PTSD or CPTSD among people with AOD use disorders. The ITQ is included in Appendix P.