People who use amphetamines 'recreationally' seem to mix it with alcohol, with very bad long-term effects on health. It also seems to drive people towards reckless and poorly-considered behavior, which is similar to the effect cocaine has on many people.
It's a wise life decision to not associate with cocaine and amphetamine addicts, certainly. However it is also curious that people in treatment for ADHD also develop a dependency on the drug, although perhaps in a more controlled manner due to it being prescribed, yet few people in the medical-pharmacological world seem to be that concerned about it.