Perhaps it doesn't get you "high" but it is highly addictive. It was once used to wean junkies off heroin. Nearly every user becomes an addict. And once addicted, they become tethered to a methadone clinic where they must go and jump through hoops to receive their dose.
Now comes reports that methadone kills. It'll be interesting to see whether the FDA does anything. They dragged their feet until 50,000 heart attacks and untold fatalities occurred with Vioxx. But they pulled PPA based Sudafed, which had been sold for nearly 4 decades, off the market due to the potential for strokes.