Most individuals with a history of chronic drug addiction are polydrug users (users of more than one drug) and will require drug rehab for all of the substances that they abuse.
Dexedrine is a stimulant prescribed medically to treat ADHD and narcolepsy, and abrupt cessation of use can cause withdrawal symptoms with chronic, legitimate use of the drug and in the case of chronic illicit abuse.
Parental alcoholism and other drug dependencies impact an adolescent's early learning about drugs and alcohol.
Methamphetamine causes a release of high levels of dopamine into the areas of the brain that have to do with the feeling of pleasure and reward, which is why the drug is so addictive.