Fast acting stimulants are prone to abuse, and people with ADHD are more likely to have addictions (because, you know, deficit of dopamine). A competent psychiatrist follows their patient throughout the treatment to evaluate if the cure is worse than the disease. If that's the case, adapt the treatment: switch to extended release medication, change medication, up/lower the dose, impose weekly sessions to keep the medication to control abuse,... The tool box is clearly not empty.

Did you ask your friends how they are doing or did you find them annoying once and decided the problem was their medication?