A survey of 3,100 moviegoers in Australia found that antismoking ads placed before movies can breed resentment and even discourage young smokers from quitting, the BBC reported June 11.

Researchers at Newcastle University found that the antismoking ad, which resembled a movie trailer, had no positive impact on 12- to 24-year-olds. More smokers who saw the film (38 percent) said they would be likely to still be smoking in 12 months than those in a control group who did not see the ad (25 percent). About the same numbers of nonsmokers who saw the ad said they would probably be smoking in a year as those who didn't see the ad.

"Caution must be exercised in the type of advertisement screened as some types of advertising may reinforce smokers' intentions to smoke," said lead researcher Diane Bull.

The study appears in the journal Tobacco Control.