3040 — Assessment of Response Style in Operation Enduring Freedom (OEF) and Operation Iraqi Freedom (OIF) Veterans
Kimbrell TA, Graham PI, and Kramer TL, Central Arkansas Veterans Healthcare System, South Central VA MIRECC, University of Arkansas for Medical Sciences; Constans JI, Southeast Louisiana Veterans Healthcare System, South Central VA MIRECC, Tulane University; Jegley SM, South Central Arkansas Veterans Healthcare System; Pyne JM, Central Arkansas Veterans Healthcare System, South Central VA MIRECC, University of Arkansas for Medical Sciences;
Unprecedented resources are being directed toward better understanding the pathophysiology and treatment of posttraumatic stress disorder (PTSD). However, there has been concern that the exceptionally high symptom report of Veterans with PTSD may impede research findings. We examined the relationship between PTSD symptom severity, a measure of symptom response style, and objective measures of PTSD.
We administered the Clinician Administered PTSD Scale (CAPS) and the Miller Forensic Assessment of Symptoms Test (M-FAST) a 25-item structured interview developed to screen for over-reporting of mental illness symptoms to a sample of 128 returning Veterans participating in a study of psychophysiologic reactivity and attentional bias.
CAPS scores ranged from 0-125 (mean = 67.1, SD = 28.3) and M-FAST scores between 0-18 (mean = 4.0, SD = 4.0). A significant and robust linear correlation was found between CAPS and M-FAST scores (r = 0.56, p = <0.001). The quadratic relationship (concave downwards) was also significant (r2 = 0.32, p = 0.01). Participants meeting current criteria for PTSD (N = 84) had significantly higher CAPS (mean = 83.25, SD = 17.13) and M-FAST (mean = 5.33, SD = 4.10) compared to participants without PTSD (N = 44) (CAPS mean = 36.23, SD = 17.72, M-FAST mean = 1.4, SD = 1.66) (p = <.001 for both comparisons. Of the 84 participants with PTSD, 21 had an M-FAST >=8 (typical cutoff for over-reporting), and this group had a mean CAPS score of 94.3. PTSD+ participants with an M-FAST <8 (N = 63) had a mean CAPS score of 79. Preliminary analysis examining the relationships between CAPS and attentional bias and acoustic startle measures were strengthened with co-variation for M-FAST.
Twenty-five percent of Veterans with a diagnosis of PTSD met a conservative criterion for symptom over-reporting. The relationship between PTSD symptom severity and M-FAST tends to taper off at higher PTSD scores, but it is not uniformly present among our Veteran PTSD sample. Co-varying for M-FAST scores strengthened and revealed relationships with objective measures.
Measures of symptom response style such as the M-FAST may have the potential to strengthen the relationship between interventions and symptom outcomes and studies attempting to identify biomarkers in PTSD.