addiction programs are trying a variety of rewards to keep patients clean and sober during the early stages of treatment, from gift cards to CD players, the Philadelphia Inquirer reported March 3.

There are now more than 60 studies from the U.S. and Europe showing that such rewards --which come under the heading of "contingency management" -- can be effective, sometimes doubling abstinence rates.

"Many of us recognize this as one of the most important and effective tools we have, but we've done a lousy job of selling it," said Charles R. Schuster, former director of the National Institute on Drug Abuse and currently at Wayne State University School of Medicine.

"In a field that frequently struggles to find effective treatments, I think [vouchers] are an attractive and effective option," added Kenneth Silverman of the Johns Hopkins University School of Medicine.

Early research by psychologist Stephen T. Higgins determined that programs needed to find rewards other than cash. "For many cocaine users, that's a cue for drug use," he said. Instead, Higgins gave cocaine users in treatment vouchers for every drug-free urine test, starting with amounts as low as $2.50 and building up to as much as $1,000 over the course of a 12-week program.

Challenges faced by such programs include a lack of funding and opposition from people who believe that the reward of treatment should be abstinence itself. "They say, 'You're paying people to stay clean,' which isn't necessarily accurate, but that's the perception," said addiction counselor Tyrone Thomas.

But many experts think that rewards should become part of standard treatment practice.