Q: Is it okay to borrow a friend's prescription for modafinil to help me stay alert?
A: Modafinil is meant to treat severe sleepiness resulting from serious disorders like narcolepsy, and it can be habit-forming. If you're having trouble staying alert during the day, you're probably not getting enough sleep. Try starting a sleep journal: Before bed each night, note your evening activities—drinking a glass of wine, surfing the Web—and then the next morning log how long it took you to fall asleep. Soon you'll notice patterns of activities that are keeping you awake.