Some of the risk factors for abuse/addiction are: 
These various risk factors suggest that only some persons who use drugs will be at high risk for making the transition to drug abuse or addiction.
In fact, data from general population surveys indicates that only a minority of illicit drug users meet the criteria for dependence. The National Co-morbidity Survey conducted in the period 1990-1992 indicated that 51% of the population 15-54 years of age in the US reported illicit drug use at some time in their lives, but only 7.5% of the population had a history of drug dependence based on meeting diagnostic criteria at some time in their lives.
In the same survey, it was found that the likelihood of drug dependence was associated with the type of drug used. For example, 31.9% of those persons who used tobacco at some time during their lives met the criteria for tobacco dependence at some time during their lives. Of those who used heroin, 23.1% were dependent at some point. Of those who used cocaine, 16.7% were dependent at some point. Of those who used stimulants such as methamphetamine, 11.2% were dependent. More detail on use and dependence is shown in Table 1, including estimated proportions of persons ages 15-54 in the coterminous US who have had a history of extramedical drug use, the proportion of those persons with a history of dependence, and the proportion of users who are dependent. The estimates in Table 1 need to be qualified by the fact that it is hard to obtain population samples that adequately represent users of illicit drugs. Still it seems to adequately illustrate the point that many people who use illicit drugs do not become dependent.
In a follow-up study, Wagner and Anthony (2002) found that in comparison to marijuana and alcohol, the use of cocaine was associated with dependence more quickly, with an estimated 5-6% of cocaine users becoming cocaine dependent during the first year of use. In contrast, dependence on marijuana or alcohol within the first year of use was about 1-1.5%. Among those with 20 years of reported cocaine or alcohol use, about 19% were dependent, regardless of drug. Among those who used marijuana for 20 years, about 9-10% were dependent (Similar types of estimates for methamphetamine and other drugs have not yet been published).