Caffeine is an alkaloid and enters in the consideration of drug because of its action on the central nervous system. Sadly now it's believed that caffeine could create malformations in chromosomes or teratogenic effects. Even so it's the most widely used stimulant with surprising rates in adults. Recently the young market includes some “energy drinks” pushing the caffeine level to the limits and creating fortunes with it, all legal in the current epoch.
The first mention of coffee appears in ancient China —at least that's the legend— five thousand years ago. It's pretty awkward that none did though in divine energy coming from that little beans, vitality from some mystical entity. The history record jumps four thousand years and then, arrives in Ethiopia after observing goats with a rare and unseen, frenetic activity.
After Ethiopia, the social habituation started in Great Britain and with it, the current massification was taking shape. So the social relation included this bitter and sour taste with some trick for making it swallowable.
But it was illegal during some time, with the first restrictions in the eighteenth century with some failed attempts near a century before.
Several countries do have regulations to restrict the quantity of this alkaloid in the market. Nevertheless that's not very logical as everybody could buy coffee without age or quantity limitations and have kilograms of caffeine without a single worry. Anyway, leaving half truths and then almost false representations of paternalism coming from organization structures, it's difficult to discuss and sustain an argument based in stimulants as interesting requests by an organism like a human being.
There are thousand examples of individuals with great focus and intellectual or physical activity without the use of a single stimulant. Furthermore, the organism is always trying to balance any habituation to include it in daily processes, so... quit it and you'll have an undesirable feeling below normal.
The best stimulant from our opinion is to make sport, but it also creates psychological addiction when you discover that is the key to good health!