In 1998, the Food and Drug Administration (FDA) approved the drug modafinil as a treatment for narcolepsy, a condition in which the brain has trouble regulating its sleep-wake cycle that results in sudden "sleep attacks" where a person falls asleep at unwanted or inappropriate times. In the years since, modafinil has become popular for another, off-label use: to boost a person's cognitive abilities—an effect that hadn't been thoroughly studied by scientists. Now a team of researchers has reviewed the literature to find that modafinil does, in fact, increase a number of important activities in the brain, according to a study published yesterday in the journal European Neuropsychopharmacology. This finding, however, doesn't ensure that your doctor will prescribe it to you to help you cram for an exam.