When my RAS was in treatment, there was a conselor there that explained that drugs alter the chemical make-up of the brain the first time someone chooses to use. Each time a drug is used after that it is like another nail in the coffin of the addict because the chemicals in the brain are damaged even more. Until the addict is clean and sober for a period of time, this imbalance causes the brain to play tricks on the addict, making them think it is a neccessity for life and without it the person will die. Until the addict hits his bottom and realizes that his brain has been lying to them nothing will change. We, as the family that love them, find it hard to understand because we don't have that same kind of chemical imbalance.
While it didn't make me feel happy hearing that my son was destoying his brain cells on a daily basis, it did help me understand a little why I was confused as to why he couldn't contol his usage.
Hope this helps.
Barb