Cocaine addiction is a serious health problem with no available medical treatment for preventing relapse. Cocaine abusers often report that upon attempting to demonstrate control over the drug by only "sampling" it following a period of abstinence, they are more likely to relapse. These small "sampling" amounts of cocaine are thought to function as priming doses. Priming doses act as a stimulus in the brain to signal that there is more cocaine available, which in turn may lead to further cocaine use. Medications that reduce the stimulating effect of the cocaine priming dose may be useful in preventing cocaine relapse. Aripiprazole, a medication that is currently used to treat schizophrenia, may be effective at reducing relapse in individuals addicted to cocaine. By enhancing activity of the brain chemicals dopamine and serotonin, aripiprazole may counter the effects of cocaine and also reduce cocaine cravings.