Some people become dependent within a few weeks of trying cocaine.
Others do not seem to become severely addicted to it. However, even these users experience a lessening of the pleasant effects of cocaine and an increase in side effects as they continue to use the drug. Over half of these 99 dropped out of the study, but nine years later 25 of them reported that they were able to use cocaine only as a social drug. Of the 46 remaining study subjects, ten became heavily dependent on cocaine. Cocaine is extremely addictive, and some forms of cocaine may be more likely to lead to addiction than others.