Rewarding people with money or prizes for abstaining from their drug of choice helps them stay in treatment—and it appears the prizes’ worth also matters—according to studies presented at APA’s 2006 Annual Convention by Nancy Petry, PhD, professor of psychiatry at the University of Connecticut Health Center.

In a 2000 study published in The Journal of Consulting and Clinical Psychology (Vol. 68, No. 2, pages 250–257), Petry tested a reward-based—or contingency management (CM)—intervention called “the fishbowl” with 42 alcohol-dependent outpatients, half of whom were randomly assigned to a CM group. Both CM participants and controls received weekly group therapy sessions and breath tests—daily for four weeks, then weekly for the next four.

When CM patients tested negative for breath alcohol content, or when they completed a goal-related activity like writing a résumé, they drew a slip of paper from a fishbowl to possibly win a prize. The prizes included small items, such as bus tokens or socks, valued at about $1, large items worth about $20, such as watches and pots and pans, and a jumbo prize worth around $100, such as a window air conditioning unit or DVD player. Eighty-four percent of patients in the CM group stayed in treatment for the entire eight-week study versus 22 percent of patients who received standard care.

In addition, the value of the fishbowl prizes appears linked to the intervention’s success, said Petry. In a 2004 paper published in Addiction (Vol. 99, No. 3, pages 349–360), Petry assigned 120 people with cocaine-dependencies to a standard treatment group, a CM group that received prizes averaging $80 or a CM group that received prizes worth $240 on average. The greater the worth of the prizes, the more effective the treatment program, she said.

“It was necessary to provide larger magnitude prizes to have a significant improvement relative to standard care,” said Petry.

—E. Packard