Yup, but mostly only for studying.
If you wanna see studies, there are plenty of studies done with caffeine. You build a tolerance and a dependence so that you can't function normally without it with regular consumption.
It's not really worse than drinking coffee.
Get the juice energy drinks, those are FUUGGEN DELICIOUS! Like rockstar orange or guava.. mmmm.
they are easily the best tasting carbonated drinks I've ever had.
I wish there are caffeine free versions of them, I'd drink it by the case.
I also take theanine supplements when consuming caffeine.
http://en.wikipedia.org/wiki/Theanine
It increases serotonin and dopamine to bring relaxation and increase congnition.