Drug addiction is considered a brain illness, because prolonged use leads to a chemical restructure of the brain, altering its function, hierarchy of needs and desires. These changes in the brain make it nearly impossible for people to stop abusing drug through willpower alone.
Fortunately, drug addiction is a very treatable disease through medically-supervised detox, professional rehabilitation, relapse prevention, and dedication. It can be overcome, and help is available. Although making the decision to seek treatment for drug addiction can be tough, it will ultimately be the best and most rewarding decision of your life.