This is a randomized, double-blind, placebo controlled study of 30 patients. Patients who qualify, as per the inclusion criteria (RASS greater than -3, less then +1, CAM positive, present gastric access) will either be given 200mg of modafinil or an identical, indistinguishable placebo. The placebo and study drug will be distributed by the hospital pharmacy. Once enrolled, each patient will be reassessed every morning to determine appropriateness for drug administration. If the RASS is less than -3 (i.e. comatose) or greater then 0 modafinil will not be given. He/she will then be assessed each morning thereafter. Due to the stimulant-like actions of modafinil, the drug will be administered only in the morning. Patients will be assessed for delirium at least twice a day; trained personnel using the Confusion Assessment Method (CAM) will do the assessment. Qualification for a delirium free day will be no positive CAM screens for 24 hours following drug administration. Additional data such as days on mechanical ventilation and progression to tracheotomy will also be collected hypothesizing that patients who take modafinil will have a shorter time to extubation therefore avoiding the need for a tracheotomy. Post-discharge from the unit, but within 48 hours, patients will be asked to participate in a survey (The Richards-Campbell Sleep Questionnaire (RCSQ) assessing their perception of daytime and nighttime sleepiness in the intensive care unit as well as their overall perception of rest. Their functional capacity will also be evaluated at this time and compared to their pre-morbid baseline. The hypothesis tested is that Modafinil restores sleep cycle synchrony in the ICU therefore increasing delirium free days and improving ICU outcomes.