Caffeine and other alerting agents

Introduction We live in a sleepy society. Contemporary pressures from home and work seem to demand more from us each day. For a variety of reasons, people find themselves getting up earlier, working longer hours, and staying up later. There never seems to be enough time – something's got to give. Unfortunately, it seems that sleep is often one of the first casualties when people try to make cuts in their daily schedule. One less hour of sleep is just one more hour available for work and play, we tell ourselves – and sometimes, we don't have any other choice. Besides, we console ourselves, if we start feeling a little sleepy, we can always just grab a cup of java at the corner café for a quick pick-me-up. But can caffeine really help? Does a cup or two of coffee really reduce sleepiness, sustain alertness, and improve performance – and if so, for how long and under what circumstances? While people use a variety of strategies to combat sleepiness, including modified work/rest scheduling, sleep optimization, sleep-inducing medications, strategic use of bright light, and napping, undoubtedly the most commonly used temporary countermeasure against sleepiness is caffeine. Routinely consumed in the form of coffee, tea, soft drinks, cocoa, and chocolate, caffeine is reported to be the most commonly used psychoactive substance in the world. Nearly 90% of Americans regularly use caffeine, and as many as 78% of automobile drivers report drinking caffeinated beverages to stave off sleepiness while driving.