Ask any recovering drug addict one question and they will tell you that beating drug addiction is one of the hardest things that they have ever been through. The battle to kick drugs is one that takes time, takes friends and family, and most importantly takes the determination and the will of the person going through the problem to dig deep down. Once the battle is under control and the addict can have back their life, they will tell you that they feel a whole lot better sober than they did high.
That is the thing about conquering drugs. A person who resorts to drugs to get through life depends on them just to function. While at first everything may be fine and dandy, eventually the drugs take control of their life and they shut down everything and anything that cares for them. No family, no friends, just drugs. The biggest part of winning the battle is gaining that trust and respect back.
Then there is the medical and chemical aspect. If a person stays high all the time, the body is tricked into thinking that the only way that they can function is with drugs in their system. While there is medication that can help ween a person away from drugs, the bottom line is in order to stop doing them you simply have to put it down and move forward. On the other hand, say you are addicted to marijuana, and are struggling to stay clean. This is more of a psychological dependency than a physical one, but it can still have consequences regardless. In that sense, beating any addiction can be a mental battle just as much as it is a physical one.
The biggest key is having some kind of support system. Whether it is through a group or friends and family. It is them they will reinforce the fact that living high is simply no way to go. You have to let go and that is the bottom line. It is a battle that will last a lifetime but if a person sticks to it they can win any fight.