As the brain systems regulating sleepiness and wakefulness are better understood, scientists will be in a better position to design treatments that target key portions of this system. For example, based on the role of histamine in keeping people awake (and hence the common side effect of anti-histamines such as diphenhydramine causing sleepiness), medications that act on histamine are under development for the treatment of excessive sleepiness. In the case of the primary hypersomnias related to excess activity of the GABA system, medications that could counteract this activity have potential to improve sleepiness. Dr. David Rye and colleagues have recently reported that use of flumazenil, one such medication, results in improvements in sleepiness when given intravenously. Two double-blind, randomized controlled clinical trials of medications that appear to influence GABA activity have recently been completed at Emory University and results should be available soon.