Cocaine is an addictive drug made from the leaves of the coca plant, which is native to South America. As a stimulant drug, cocaine speeds up activity in the central nervous system. Because of this, when individuals use the drug, they may temporarily feel excited, alert, focused, and energetic. But once the effects dissipate, they might feel lethargic, depressed, irritable, weak, and have trouble concentrating, which may make you want to use cocaine again. This can often create a vicious cycle in which an individual uses the drug and then turns to the drug once again to lessen withdrawal symptoms following their most recent use.