Trail making test cut-offs for malingering among cocaine, heroin, and alcohol abusers.

The Trail Making Test (TMT) is frequently used to screen for cognitive impairments in substance abusers; however, an existing problem is that substance abusers may give poor effort and the TMT results may not be valid. In this study, cutting scores for malingering were developed from three samples drawn from electronic files of data from the Drug Abuse Treatment Outcome Study (DATOS), a naturalistic, prospective cohort study that collected data from 1991-1993 in 96 drug abuse treatment programs in 11 cities in the United States. The DATOS enrolled 7689 substance abusers. The three drawn samples were for subjects with primary drugs of abuse. Number of subjects were as follows: alcohol-1000, cocaine/crack-4306, heroin-1548. Data were analyzed to determine number of substance abusers that fell beyond the upper end of the distribution of TMT scores at the ten, five, and one percentiles. These percentiles were set for alcoholics, cocaine abusers, and heroin abusers. The proper use of the cut-off scores is to alert clinicians to the increasingly higher probability of poor effort when a substance abuser in one of the three groups scores beyond the one percent cut-off or his or her sample of primary drug of abuse. Clearly, the use of these cut-offs needs further empirical validation.