What exactly is it that causes addiction on a biological level? Basically, when a drug is abused, the body becomes imbalanced. The body is imbalanced in such a way that it builds a dependency for the drug. This dependency causes a sense of depression or physical pain when withdrawal occurs, further solidifying the addiction.

Since the drug causes an imbalance in the body that can only be quelled by the drug itself, the only way to beat an addiction is to unbalance the body once again by removing the drug. Unbalancing the body does cause the symptoms of withdrawal, which can range from mild to severe, but the only way to beat a drug is to beat this imbalance of the body until it can live without the drug again.