Does Doing One Drug (Like Cigarettes or Marijuana) Lead to Abuse of Other Drugs?

Whether doing one drug will lead to doing another depends on each individual person. For example, some people who use marijuana do not go on to abuse other illicit drugs, but most people who abuse other drugs have previously used marijuana. Basically, being exposed to peers who use drugs, having greater access to drugs, and having problems in the first place that led to the initial drug use could all make other drug use more likely.