Graphic images increase the impact that cigarette warning labels have on young adults in the United States, a new study says.

The study included smokers and non-smokers, ages 18-25, who took part in a nationwide survey that asked how much they learned about the dangers of smoking from cigarette warning labels.

Increasing the awareness of the "true consequences" of smoking may not only encourage people to quit or even never start smoking, "but may actually drive the emotional experience of the label, which we know is an important predictor of motivation," said study author Renee Magnan, an assistant professor of psychology at Washington State University Vancouver.

The labels used in the study emphasized smoking-related dangers such as lung cancer, heart disease and stroke, impotence, eye disease, and head, neck, throat and mouth cancers.

Some were text-only while others included text and graphic images such as facial scars, rotting teeth, diseased body parts or people dying in hospital beds.

The participants overwhelmingly said that the warning labels with images gave them a much better understanding and more knowledge about the risks of smoking, triggered more worry about the effects of smoking, and did more to discourage smoking, compared to text-only warning labels.

The study was published online in the journal Annals of Behavioral Medicine.

The findings suggest that clearer, more informative warning labels on cigarettes are more likely to be heeded by smokers, Magnan said.

"Although this is a preliminary investigation, from a policy perspective, these outcomes suggest that focusing on deriving greater understanding and knowledge from such labels may have more impact in terms of both motivational and emotional responses," Magnan said in a university news release.

"Importantly, however, these labels are only a small piece of what should be a larger campaign to educate the public on the dangers of smoking," Magnan added.

-- Robert Preidt