What is the main drawback in methadone treatment for a heroin addict?

The main drawbacks for an addict, are that methadone withdraws are more severe and prolonged than coming off of 'street heroin'. Most addicts taking methadone are on it for a long time. Methadone is an addictive substance - the longer you are on it the more you need! Which is why the amount of addicts who actually achieve abstinence whilst using methadone is very low. Methadone dose not stop the obsessive behaviour or thoughts associated with addiction. Addicts usually end up with two addictions - to the methadone and to the heroin! In general, and at best, it can be described as a harm reduction measure. It is cheap to produce and controllable by the Authorities. Which is why it has been, and continues to be used.