Reliability and Validity of the Diagnostic Interview Trauma and Stressors- Intellectual Disability in Adults with Mild Intellectual Disabilities or Borderline Intellectual Functioning

Abstract

ABSTRACT Objective To assess the reliability and construct validity of the Diagnostic Interview Trauma and Stressors- Intellectual Disability – Adult version (DITS-ID-adults) in adults with mild intellectual disabilities or borderline intellectual functioning (MID-BIF). Method The DITS-ID-adults, Brief Symptom Inventory–18 (BSI–18), and Impact of Event Scale-Intellectual Disability (IES – ID) were administered to 97 participants with MID-BIF who lived in supported housing. The Anxiety, Depression, and Mood Scale (ADESS) and Behavior Problems Inventory (BPI) were administered to their relatives. Results The interrater reliability of the DITS-ID-adults was good to excellent. The construct validity of the DITS-ID-adults was good, based on positive correlations between the BSI–18, IES-ID, ADESS and DITS-ID-adults, and mainly positive correlations between the BPI and DITS-ID-adults (r = .21 to r = .75). Reporting potentially traumatic events listed under the A criterium for PTSD was associated with fulfilling PTSD symptom criteria. In this sample, 58% were classified with post-traumatic stress disorder (PTSD) according to the DITS-ID-adults, while PTSD diagnosis on file was low (7%). Conclusion The present findings support the DITS-ID-adults as a reliable and valid basis for classifying PTSD in individuals with MID-BIF.