Adderall, Ritalin and Focalin are usually at the top of the list of the most addictive stimulants. These medicines are often prescribed to help with ADHD or narcolepsy, but their ability to give you a quick boost in focus and energy can easily lead to stimulant addiction. The more you take, the more your body craves them, so it is critical you follow your doctor’s orders and never take stimulants without a prescription.