Should the retention trial of the Test of Memory Malingering be optional? A reply.

Greve and Bianchini (2006) have posed the question, “Should the Retention trial of the Test of Memory Malingering be optional?” The answer to this question is important given the finding by Slick, Tan, Strauss, and Hultsch (2004) that the Test of Memory Malingering (TOMM; Tombaugh, 1996) is one of the most commonly used malingering tests among surveyed psychologists. Greve and Bianchini (2006) suggest the Retention Trial should always be administered, based on their finding that 3% of their sample of 300 patients with traumatic brain injury or chronic pain obtained a score below 45 on the Retention Trial of the TOMM, after obtaining passing scores (45 or greater) on Trial 2. The authors suggest that administering the Retention trial “detected” this minority of malingerers that would have otherwise not been identified (Greve & Bianchini, 2006). It is reported in the TOMM manual that 3.1% of the cognitively impaired group, not involved in litigation or considered “at risk” for malingering, scored below 45 on the Retention Trial (Tombaugh, 1996). This raises the possibility that the probable malingerers in Greve and Bianchini’s study scored below 45 on the Retention Trial for reasons other than frank malingering. Greve and Bianchini (2006) suggest always administering the Retention trial even though their data do not significantly differ from the statistics published in the manual. It appears that Greve and Bianchini (2006) may simply prefer a more conservative criterion rule. In their article, Greve and Bianchini (2006) report that they administer the Retention trial of the TOMM (Tombaugh, 1996) in “standard fashion” to all patients. The authors also repeatedly refer to an “early termination criteria,” implying that all three trials of the TOMM are supposed to be administered to all individuals and that one is remiss if they do not do so. However, according to the TOMM manual, the Retention Trial is an optional test that need be administered only if the score of Trial 2 is less than 45 (Tombaugh, 1996, p. 18). In addition, Greve and Bianchini (2006) report that they use standard scoring and stated that their scoring is “consistent with the manual”. Further, they state that scores of 45 or higher on Trial 2 and the Retention trial were considered passing while scores below 45 on either Trial 2 or on the Retention trial are suggestive of malingering. Although the manual states that any score lower than 45 on Trial 2 or on the Retention Trial should raise concerns that