DESCUENTO TEMPORAL ASOCIADO AL USO DE COCAÍNA DELAY DISCOUNTING ASSOCIATED WITH COCAINE USE

In delay discounting tasks, the rate of discounting monetary rewards is greater for individuals who use drugs than for control participants. This result has been observed in individuals who use a particular drug (mono-consumers). In this study we examined delay discounting of hypothetical money rewards and losses by 102 men: 38 cocaine-dependent individuals (mono-consumers), 34 cocaine-dependent individuals who also abused a second drug (poly-consumers) and 30 non-drug-using matched controls. All participants were offered choices between hypothetical monetary rewards ($50$200) available immediately and larger rewards ($200-$3,000) available after delays ranging from one week to three years. Participants were also offered choices between an immediate hypothetical money loss ($750$1,500) and a money loss (up to $1,500) after the varying delays. Results showed that the rate of monetary reward discounting was generally greater for mono-consumers and poly-consumers than for control participants. Poly-consumers discounted monetary rewards more steeply than mono-consumers when the amounts of the hypothetical rewards were low. This result suggests a magnitude effect on delay discounting between mono-consumers and poly-consumers. No differences were found in delay discounting of losses among the three groups of participants. This finding is consistent with previous studies and shows that gains are discounted at a higher rate than comparable losses.