Overdrive is when you get hyper-active due to being over-tired, over-worked, or over-stressed. Common symptoms include slurred or incoherrent speach, laughing histerically over stupid things, and improper brain function, while in a sober state.
J: hey man how's it going?
K: whats the dealy-yo my mizzle muahhahaha, like, ur face is stupid hahahha!!!!
J: dude, you're in overdrive.