Depression and trail making test scores in a sample of cocaine abusers.

Depression effects on the Trail Making test (TMT), a test often used for screening cognitive impairments, were examined in a sample of cocaine abusers in drug abuse treatment programs. A mixed race sample of 4299 subjects was drawn from electronic files of data from the Drug Abuse Treatment Outcome Study (DATOS). DATOS was a naturalistic, prospective cohort study that collected data from 1991-1993 in 96 programs in 11 cities in the United States. Data were analyzed to determine the effects of depression on the TMT scores A and B, and also derived indices created by adding, subtracting, multiplying, and dividing parts A and B of the TMT in this large treatment sample of cocaine abusers. The variables of sex, age, ethnicity, and education were included in analyses to control for demographic effects. The TMT part A and the difference score were the least sensitive TMT scores to the effects of depression but all TMT R-squares were quite small.