Clinical Profile of US Combat Veterans with PTSD on M-FAST Items

Background: The Miller Forensic Assessment of Symptoms Test (M-FAST; Miller, 2001) is a widely used but controversial instrument promulgated to measure malingering. Its use is encouraged by publications which are methodologically flawed such as the recent meta-analysis by Detullio et al. (2019). In this study, we examine which of M-FAST’s 25 items are most frequently endorsed by veterans with posttraumatic stress disorder (PTSD). Method: Using tabular data published by Wolf’s team in 2020, we identified from a clinical perspective, the 7 M-FAST items endorsed by the highest proportions of 121 US combat veterans with a probable current diagnosis of PTSD. Since the M-FAST diagnostic cutoff is 6 or more points and each endorsed item counts as one point, the 7 most frequently endorsed M-FAST items provide a clinical profile, via their content, as to which items are most frequently involved in misdiagnosing veterans as malingerers. Results and Discussion: Item 2 (“feeling depressed most of the time”) was endorsed by 67.8%, Item 23 (“feeling that I don’t really matter”) by 56.2%, Item 20 (formication) by 28.9%, and Item 17 (phantosmia, i.e., “false sensation of an odor”) by 24.0%. Formication and phantosmia are legitimate neuropsychological symptoms that may occur with whiplash injuries and head trauma or exposure to toxic chemicals in combat. Item 21 (“at times hearing music coming from nowhere”) endorsed by 22.3% may describe spontaneous intrapsychic activity of musically inclined persons. Item 14 (“Sometimes it seems as if someone controls my symptoms, turning them on and off”) endorsed by 20.7% may reflect the unpredictable fluctuation of frequency and severity of PTSD symptoms. Item 1 (“restlessness while seated”) endorsed by 19.8% is scored in the M-FAST as a discrepancy between the patient reporting that he “often” feels restless, and the examiner’s observation that no such nonverbal behavior during the brief M-FAST interview was noted. Restlessness is a post-concussive symptom that is not necessarily always present, such as during the M-FAST interview. Conclusions: All 7 most frequently endorsed items by combat veterans are neither exclusive to malingerers nor pathognomonic of malingering. They form a pattern of legitimate medical symptoms fallaciously scored and interpreted in the M-FAST’s system as indicators of malingering.