Cognitive Performance Following Modafinil versus Placebo in Sleep-deprived Emergency Physicians: A Double-blind Randomized Crossover Study


*Loma Linda University Medical Center, 11234 Anderson Street, PO Box 2000, Room A-108, Loma Linda, CA 92354. Fax: 909-558-0121; e-mail:


Objectives: Modafinil has recently been approved for the treatment of shift work sleep disorder, making it potentially available for shift-working emergency physicians. The authors' objectives were to determine whether modafinil improved cognitive performance of emergency physicians following overnight shifts and to record symptoms and subjective evaluations of the effect of modafinil on the participants.

Methods: This was a randomized, double-blind, placebo-controlled crossover study that followed CONSORT guidelines. Participants were assigned to one of two study groups, with study sessions occurring at least seven weeks apart, and received either modafinil or placebo depending on their random allocation. Testing after night shifts included a coding task and an AX version of the Continuous Performance Task, both of which test cognitive function. Participants also completed visual analog scales for three subjective outcomes, and symptoms were elicited.

Results: Modafinil facilitated performance on long interstimulus-interval AX trials (F [1, 23] = 6.65, p = 0.1) and marginally reduced errors on AY trials in the Continuous Performance Task (F [1, 23] = 3.59, p = 0.07), suggesting facilitation of sustained attention, cognitive control, and working memory. Additionally, modafinil, compared with placebo, facilitated performance on the coding task at the first session. Subjective data from visual analog scales confirmed that modafinil increased perceived alertness during the simulated patient care sessions but worsened sleep onset when opportunities for sleep arose.

Conclusions: Modafinil increased certain aspects of cognitive function and subjectively improved participants' ability to attend post–night-shift didactic sessions but made it more difficult for participants to fall asleep when opportunities for sleep arose.