Psychometric properties of the Portuguese version of the Acceptance and Action Questionnaire-Trauma Specific (AAQ-TS): A study with Portuguese Colonial War Veterans

•This is the first study of the psychometric properties of the AAQ-TS.•Assessment of trauma-related psychological (in)flexibility and associated problems.•The Portuguese version is valid and reliable.•Convergent and discriminant data lend confidence to its use in several settings.•Particularly useful in the context of ACT and mindfulness-based therapies.

BackgroundThe Acceptance and Action Questionnaire-Trauma Specific (AAQ-TS) is a self-report measure designed to assess-trauma-related psychological (in)flexibility, as conceptualized in Acceptance and Commitment Therapy. However, there are no studies to date regarding its psychometric properties. This study explores such properties in the Portuguese version of the AAQ-TS, in Portuguese Colonial War Veterans.MethodA Principal Components Analysis (PCA) was conducted in a sample from the general population of war Veterans (N=371). Confirmatory Factor Analysis (CFA) as well as reliability and convergent validity studies were performed in a different sample from the same population (N=312). For the discriminant validity a clinical sample with a war-related PTSD (N=42) and a non-clinical sample without PTSD (N=44) were used.ResultsThe CFA suggested a re-specified 15-item model with good global adjustment and factorial validity. The AAQ-TS showed internal consistency, a good temporal reliability, convergent validity with psychopathological symptoms (related to PTSD, anxiety, depression and stress) and peritraumatic dissociation (altered awareness and depersonalization/derealization). The questionnaire also discriminates between war Veterans with and without a PTSD diagnosis.LimitationsThe major limitation relates to the samples' characteristics and sampling methods, which can limit the generalization of results.ConclusionThe Portuguese version of the AAQ-TS is a reliable and valid measure to assess experiential avoidance related to trauma in Portuguese Colonial War Veterans.