Conducted by Emory University public health researchers, the study analysed the marijuana use and self-reported sexual behaviour of 439 sexually active black females in the age group of 15-21 years.
It was discovered that black girls who used marijuana had significantly higher rates of incident STDs than non-marijuana users (32 percent compared to 23 percent).
In fact, the researchers found that those who used marijuana, also had more sex partners, riskier sex partners, including a partner just released from jail, and more recent episodes of engaging in vaginal sex while their partner was under the influence.
"While adolescent African-American females remain a high-risk group for STDs, little research has examined their marijuana use, sexual behaviors and incidence of STD infection," said study co-author Ralph DiClemente, PhD, Candler professor of public health at Emory's Rollins School of Public Health.
He added: "Although no differences in condom use were identified between marijuana users and non-users, results suggest that marijuana users are engaging in sexual acts with riskier partners and under riskier circumstances, and had higher rates of STDs."
The researchers advised STD and HIV intervention programs designed for adolescent black females that not only promote condom use, but also emphasize the risks of drug use and STD and HIV infection.
The study was presented at the International AIDS Conference in Mexico City.