When do you take the addict off the methadone? That's essentially the dilemma facing the U.S. Federal Reserve's 19 policy makers when they meet in Washington this week. Since the height of the financial crisis in 2008, the U.S. economy and everyone with a stake in it have become hooked on the massive amounts of stimulus injected by the U.S. central bank. Now, though, consensus is building among policy makers that the time is nearing to adjust their $85 billion-a-month asset purchase program, dubbed quantitative easing, but divisions remain over just when to start reducing the dosage. In recent weeks, even the program's most ardent supporters, including Chairman Ben Bernanke, have begun signaling a willingness to dial back the pace of bond buying before too much longer. Meanwhile, those who have never liked it insist the moment has arrived and worry the Fed's grip on markets is weakening the longer the program remains in full force. "We haven't taken st