There seems to be some confusion about how methadone works. Here's the Cliff's notes version:
Methadone is a very effective pain medication. Withdrawal hurts. Methadone use during addiction treatment allows the addict to get through withdrawal without as much of the pain and discomfort suffered if one goes "cold turkey" (a major reason why addicts fail when trying to get off the stuff, whatever the "stuff" may be). The average addict will try to rehabilitate AND FAIL several times before either being successful or giving up -- or dying.
Methadone is a synthetic opoid, which means it works well in the treatment of other opioids, such as heroin. It allows an addict to be FUNCTIONAL, because they get the relief of taking the drug without the euphoria.
There are two ways it can be used: either as a type of analgesic (pain reliever) to get the addict through initial withdrawal or as a LONG TERM TREATMENT PLAN as an opioid inhibitor -- typically to ensure that the addict can pursue a productive life. Methadone treatment can go on for years, because it's goal is to maintain a less risky lifestyle, not to stop the addiction. One can go for their maintenance dose in the morning, and go off to work like a "normal" person. People who are able to function as "normally" as possible tend to have good stuff in their lives (jobs, families, friends) who allow them to hope for the future -- hope is a big factor in an addict's recovery.
Methadone treatment MUST be monitored by a medical professional, or preferably, a TEAM of medical professionals to have the effect of returning the addict to some semblance of a "normal" life, whether after short-term intense treatment where the patient is switched to methadone and then weaned off of it (typically "inpatient" treatment) or as a long-term maintenance treatment. The amounts distributed in outpatient treatment centres (where most people go in the morning, get their dose, then go on to work, etc.) are not enough to achieve a "high", but are enough to keep the effects of withdrawal at bay.
The problems, as with many drugs, occur when someone takes more than they should. In this case, it is a drug, like any other. You see this in people who HAVEN'T YET reached the point where they are truly ready for recovery. Outpatient clinics are not for these people -- they are for those who want to return to a functional life, but need help to get there. That's why out-patient methadone treatment programs require regular urine tests.
There are side effects and risks, as there are with any drug. The side effects can be bad, but so can continuing life as a heroin user -- needle sharing and it's risk of HIV and AIDS tops that list, but the risks of overdosing, or causing harm or death to another while using are there, as well. Anyone here ever seen a newborn baby of a heroin-addicted mommy? It isn't pretty.
Methadone is *NOT* for everyone, I agree, but it can play a very, very important role in treatment, and should not be dismissed when it can give hope of a relatively normal life to those who otherwise would continue on their downward spiral that ONLY ends in one place.