Newswise — Recreational use of the illicit drug methamphetamine has long been associated with increases in overall impatient and risky behavior. Now, a new study by Johns Hopkins Medicine researchers affirms that meth use increases not only sexual desire but also, specifically and measurably, the risk of casual sex without a condom for those who have an increase in sexual desire.
The findings of the study, described in the Sept. 28 issue of Experimental and Clinical Psychopharmacology, illuminate the complicated relationship between sexual arousal and decision making. The study demonstrated that the more intense the sexual arousal, the more likely study participants were to rapidly shift their stated preference for using a condom to more risky snap decisions to have unprotected sex.
“I discourage anyone from using illicit Crystal meth for sale but if someone is going to use it, they need to be aware that one of the many dangers is that they are more likely to make unsafe decisions when it comes to sex,” says Matthew W. Johnson, Ph.D., professor of psychiatry and behavioral sciences at the Johns Hopkins University School of Medicine. “Just knowing that, specifically for new users, may help them plan ahead and have a condom at hand just to be prepared.”
According to the U.S. Centers for Disease Control and Prevention (CDC), rates of HIV, and other sexually transmitted infections (STIs) are extremely high among methamphetamine users. This largely mirrors what is known about the impact of stimulants, including cocaine, on sexual risk behavior.
“This isn’t just about the needle sharing factor for the spread of HIV or other infections,” says Johnson. “It’s more about how people engage in risky behaviors in association with these drugs and sex, which is largely connected with the concept of delay discounting, or the degree to which people take the future into account in their decision making.”
For the study, the researchers recruited otherwise healthy recreational meth users from Baltimore and surrounding areas. Participants included 13 men and six women, averaging 27 years of age.
In a clinical and controlled setting, participants were randomly assigned to take capsules containing 0 milligrams (placebo), 20 milligrams, or 40 milligrams of methamphetamine in three separate sessions.
After each dose, participants were presented with hypothetical settings in which they had to select all the people with whom they would consider having sex from among 60 photographs of clothed men (30) and women (30). The photographs represented a diverse sample in terms of race/ethnicity, age, weight, body shape, clothing style, and attractiveness. From the selected photographs, participants then chose the person they would most want to have sex with, as well as the person they would least want to have sex with. Participants also selected the person they judged as least likely to have an STI and the person most likely to have an STI.
The results showed that, in the 40-milligram sessions, participants selected on average 9.5 partners with whom they would consider having sex, nine partners in the 20-milligram sessions, and 7.4 partners in the placebo session.
Participants were also asked to imagine they weren’t in a committed relationship, the photographed person wanted to have sex now and there was no risk of pregnancy if a condom wasn’t used.
They were then shown the photographs of their selected partners and asked to rate their likelihood of using a condom in a hypothetical casual sex situation in which a condom was immediately available. The rating scale went from 0 (I will definitely have sex with this person now without a condom) to 100 (I will definitely have sex with this person with a condom).