I dunno if this has been said yet, but..
for those who aren't getting anything out of caffeine or energy drinks etc... if you have ADHD/ADD, some stimulants will have a reverse effect and make you crash like a mofo, i have ADD and coffee tends to get me tired, i thought it was just a sugar crash but it would happen like 10-15 minutes after drinking it. Some energy drinks will work for me, some others just get me even more tired.. lol