Methamphetamine Administration Dose Effects on Sexual Desire, Sexual Decision Making, and Delay Discounting.

Public Health Significance We tested the effects of methamphetamine administration on sexual desire and hypothetical condom-use decisions as measured by the Sexual Delay Discounting Task. Compared to placebo, methamphetamine caused group-level, dose-related increases in sexual desire, with decreased reported likelihood of condom use among individual participants who experienced increased desire and increased likelihood of condom use in those who experienced decreased desire. These mixed results may be consistent with methamphetamine's role as both a treatment for attention-deficit/hyperactivity disorder and as a drug of abuse associated with increased sexual risk taking. Correlational evidence has linked methamphetamine use and HIV sexual risk behavior, but the direct effects of methamphetamine on sexual desire and sexual decision making in humans have not been tested. This study was designed to test the effect of methamphetamine administration on sexual desire and hypothetical condom-use decisions as measured by the Sexual Delay Discounting Task. Recreational stimulant users (n = 19) participated in this within-subject, placebo-controlled study comparing the effects of 0 mg, 20 mg, and 40 mg of oral methamphetamine. Compared to placebo, methamphetamine caused dose-related and time-related increases in a single-item sexual desire rating and some standard stimulant abuse liability ratings, as well as dose-related increases in the Sexual Arousal and Desire Inventory (SADI; a multidimensional scale capturing positive and negative aspects of desire/arousal). However, methamphetamine caused no significant mean differences in likelihood of condom use within the Sexual Delay Discounting Task or the Monetary Discounting Task. SADI scores were negatively correlated with change from placebo in condom use likelihood in the Sexual Delay Discounting Task for some partner conditions (i.e., decreased reported likelihood of condom use in participants who experienced increased desire/arousal and vice versa). These mixed results may be consistent with methamphetamine's role as both a treatment for attention-deficit/hyperactivity disorder and as a drug of abuse associated with increased delay discounting, and they suggest that methamphetamine's effects on discounting may be modulated by the reinforcing properties of what is being discounted. Delay discounting may be an understudied element of risky sexual decision making, particularly among individuals who use methamphetamine.