Preliminary validation of the IMQ-5: A brief intrusive memory questionnaire for PTSD

Intrusive memories and the associated clinical features (e.g., sense of nowness, sense of danger, fears of losing control) serve as hallmarks in the development and maintenance of PTSD and are a central focus in the treatment of the disorder. Despite their importance, no existing measure assesses for the relevant clinical features alongside intrusions. To address this gap, we aimed to develop and evaluate a brief intrusive memory questionnaire for clinical and research applications. A sample of treatment-seeking veterans (N = 185) were administered an item pool of intrusion questions together with measures of PTSD (PCL-5) and depression (PHQ-9). Intrusion items were subjected to tests of relative importance, which identified five items we termed the IMQ-5 (Intrusive Memory Questionnaire-5) that comprised a single factor, CFI (0.99), TLI (0.97), RMSEA (0.07, 90% CI [0.00, 0.14]), SRMR (0.03). The IMQ-5 evidenced greater convergent validity with the PCL-5 (r = .69) than the PHQ-9 (r = .51), and demonstrated an ability to distinguish probable PTSD from subthreshold symptoms (AUC = 0.83, 95% CI [0.74-0.93]). Implications of the findings and suggestions for future research are discussed.