From 1998 to 2006, the number of methadone prescriptions increased by 700 percent, according to DEA figures. Between 1999 and 2005, deaths that had methadone listed as a contributor increased nearly fivefold, to 4,462, a number that federal statisticians say is understated because states do not always specify the drugs in overdoses. By Erik Eckholmand Olga Pierce The New York Times