FRIDAY, May 12, 2017 (HealthDay News) -- Young men who prefer pornography to real-world sexual encounters might find themselves caught in a trap, unable to perform sexually with other people when the opportunity presents itself, a new study reports.

Porn-addicted men are more likely to suffer from erectile dysfunction and are less likely to be satisfied with sexual intercourse, according to survey findings presented Friday at the American Urological Association's annual meeting, in Boston.

For the study, researchers surveyed 312 men, aged 20 to 40, who visited a San Diego urology clinic for treatment. Only 3.4 percent of the men said they preferred masturbating to pornography over sexual intercourse, the survey found.

But the researchers found a statistical relationship between porn addiction and sexual dysfunction, said lead researcher Dr. Matthew Christman. He is a staff urologist with the Naval Medical Center in San Diego.

"The rates of organic causes of erectile dysfunction in this age cohort are extremely low, so the increase in erectile dysfunction that we have seen over time for this group needs to be explained," Christman said. "We believe that pornography use may be one piece to that puzzle. Our data does not suggest that it is the only explanation, however."

Christman said the problem could be rooted in the biology of addiction.

"Sexual behavior activates the same 'reward system' circuitry in the brain as addictive drugs, such as cocaine and methamphetamines, which can result in self-reinforcing activity, or recurrent behaviors," Christman said.

"Internet pornography, specifically, has been shown to be a supernormal stimulus of this circuitry, which may be due to the ability to continuously and instantaneously self-select novel and more sexually arousing images," he added.

Watching too much internet porn can increase a person's "tolerance," the same as with narcotics, Christman explained. Regular porn watchers are less likely to respond to regular, real-world sexual activity, and must increasingly rely on pornography for release, he said.

"Tolerance could explain the sexual dysfunction, and can explain our finding that associated preferences for pornography over partnered sex with statistically significantly higher sexual dysfunction in men," Christman said.