A pilot study on the adequacy of the TOMM in detecting invalid performance in patients with substance use disorders

Abstract

ABSTRACT Objective: The validity of neuropsychological test performance has scarcely been studied in patients with substance use disorders (SUD), despite the possibility that some SUD individuals may distort their performance for compensation seeking (e.g., work leave, permanent or total disability, or the designation of services such as sheltered housing). Thus, the aim of the present study is to determine: (i) the possible utility of the Test of Memory Malingering (TOMM) in detecting invalid test results among SUD patients, and (ii) the percentage of individuals that underperform the TOMM among SUD patients seeking compensation. Method: Seventy-seven patients (59 men and 18 women) with SUD in outpatient treatment with an age range between 20 and 59 years were divided into two groups: SUD patients without compensation seeking (n = 41), and SUD patients with compensation seeking (n = 36). Participants performed a neuropsychological assessment with measures of processing speed, working memory, inhibition, verbal memory, cognitive flexibility, and decision-making, that also included the TOMM. Results: Our results demonstrate that there were no significant differences on TOMM performance between the two groups. Only one participant underperformed the TOMM (1.3% of the sample). Results showed cognitive impairment in the sample, but no differences between the groups on the different neuropsychological measures. Conclusions: This constitutes the first study to explore the capacity of a forced-choice test to detect invalid test results in an SUD population. There was a high performance on the TOMM among the SUD participants of our study despite their cognitive impairment, indicating adequate effort in their neuropsychological test performance. Further, these findings suggest that the probability of showing invalid neuropsychological performance among SUD compensation seeking patients is much lower than what has been found in other populations, such as in mild brain injury patients.