Detox Methadone Withdrawal | A Basic Science of Addiction
In many cases when a person begins using drugs it is their own decision. They might say something like, “Oh, maybe I should try it just this once.” One of these drugs could be an opiate analgesics like heroin, Vicodin, or OxyContin. In some cases, some people can become addicted right from the start, and in a number of drug treatment centers methadone can be used to help alleviate withdrawal symptoms. This drug, however, can be abused and some end up with detox methadone withdrawal symptoms. 
Methadone and other opiate analgesics influence the reward pathway, which is responsible for driving our motivational feelings of reward and behavior. The cells responsible to pass the correct signals to the brain are called neurons, and the information flows from one neuron to the other by crossing a small gap called the synapse. These pathways can become skewed when there is an extended period of opiate abuse.
So, in the end a person’s reward signals are crossed and they find themselves behaving in ways, drug seeking and obsession, completely out of character.