The Sexual Discounting Task: HIV risk behavior and the discounting of delayed sexual rewards in cocaine dependence

Abstract

Background: Cocaine dependence is associated with high rates of sexual risk behavior and HIV infection. However, little is known about the responsible mechanism(s).

Methods: Cocaine-dependent individuals (N=62) completed a novel Sexual Discounting Task assessing decisions between immediate unprotected sex and delayed sex with a condom across four hypothetical partners: most (and least) likely to have a sexually transmitted infection (STI), and most (and least) sexually desirable; a real rewards money delay-discounting task, and self-reported sexual risk behavior using the HIV Risk-Taking Behavior Scale (HRBS).

Results: Sexual Discounting Task results were largely systematic and showed a strong effect of delay in decreasing condom use. Sexual discounting (preference for immediate unprotected sex) was significantly greater when making responses for partners judged least (compared to most) likely to have an STI, and for partners judged most (compared to least) desirable. Differences in sexual discounting were significant after controlling for differences in condom use (with no delay) between conditions. Greater discounting in 3 of the 4 Sexual Discounting Task conditions, but not in the money discounting task, was associated with greater self-reported sexual risk behavior as measured by the HRBS.

Conclusions: Results suggest that delay is a critical variable strongly affecting HIV sexual risk behavior, and that the Sexual Discounting Task provides a clinically sensitive measure of this phenomenon that may address a variety of questions about HIV risk in future research. The wealth of behavioral and neurobiological data on delay discounting should be brought to bear on HIV education and prevention.

Figure 1

Sexual discounting group median data with best-fit hyperboloid functions for the four conditions. The top panel shows data from the “most likely to have an STI” and “least likely to have an STI” conditions. The bottom panel shows data from the “most want to have sex with” and “least want to have sex with” conditions.

Figure 2

Sexual discounting group median data with best-fit hyperboloid functions for the four conditions. Data have been normalized relative to likelihood of using a condom at no delay, so that delay discounting differences across groups are not confounded by differences in condom use regardless of delay. The top panel shows data from the “most likely to have an STI” and “least likely to have an STI” conditions. The bottom panel shows data from the “most want to have sex with” and “least want to have sex with” conditions.