Doctors prescribe drugs just as addictive as street drugs all the time, in fact in the case of Adderall we give kids the same drug we make scary TV shows about.
Many people will be surprised to discover that Bayer, better known for Asprin, at one time manufactured and sold Heroin. After Heroin, which is an opioid, was banned scientists went to work creating a new painkiller that worked on the same receptors in the brain. This research by Pharmaceutical companies led to the creation of OxyContin which acts on the same receptors.