A deposit contract method to deliver abstinence reinforcement for cigarette smoking.

Eight smokers were randomly assigned to a deposit contract ($50.00) or to a no-deposit group. Using a reversal design, participants could recoup their deposit (deposit group) or earn vouchers (no-deposit group) for smoking reductions and abstinence (breath carbon monoxide [CO] < or =4 parts per million) during treatment phases. Treatment was delivered via a novel Internet-based method to monitor smoking status. Although equivalent decreases in breath CO and abstinence were observed during treatment in both groups, $178.50 in vouchers were distributed to participants in the no-deposit group, whereas a small surplus remained in the deposit group. A deposit contract method may represent a cost-effective model to deliver abstinence reinforcement for cigarette smoking.