Modafinil, Sleep, and Cognition in Cocaine Dependence

A relatively new treatment for the excessive daytime sleepiness (EDS) associated with inadequate sleep is the drug modafinil. Modafinil decreases subjective reports and objective measures of daytime sleepiness under conditions of sleep restriction, while enhancing cognitive performance. At the same time, sleep quality does not appear to be affected significantly. Interestingly, recent clinical trials in cocaine-dependent populations suggest that modafinil reduces the relapse to cocaine use, by unknown mechanisms. We propose to employ both subjective and objective measures of nocturnal sleep and daytime sleepiness, as well as measures of general cognitive performance and sleep-dependent memory consolidation, to explore potential mechanistic relationships between cocaine abstinence, EDS, and modafinil's efficacy in preventing cocaine relapse. The following specific aims are proposed: Specific Aim 1: To establish whether objective measures of poor nocturnal sleep (e.g., reduced total sleep time and sleep efficiency) that progressively characterize periods of sustained cocaine abstinence are also associated with objective evidence of excessive daytime sleepiness (EDS). Specific Aim 2: To establish the ability of modafinil to reverse the excessive daytime sleepiness (EDS) and deficits in cognitive performance that characterize cocaine abstinence. Specific Aim 3: To conduct a pilot study to determine whether the observed abnormalities in objective sleep, EDS, and/or cognitive function predict relapse to cocaine use and/or whether successful abstinence from cocaine is associated with normalization of the same.