There is no scientific evidence that graphic warning labels, such as those on packs of cigarettes, are effective, and these warnings may even backfire, according to Maastricht University researchers Gjalt-Jorn Peters, Rob Ruiter and Gerjo Kok, who recently published their findings in the journal Health Psychology Review.

Scary graphic warning labels are a popular tool among policy makers, but there has been no clear consensus within the scientific community regarding their efficacy. The researchers looked at an initial selection of 295 publications exploring so-called "fear appeals", including graphic warning labels, then eliminated studies that had methodological problems (e.g. the authors did not actually carry out any experiments).

“To our shock, it turned out that there are only six studies that investigated the relevant theory properly. Not only is there little evidence that could support the use of graphic warning labels, but if you combine the evidence that is available, it turns out that at best, the use of graphic warning labels only has a small effect, while in the worst case, it may even backfire", say the researchers.

According to the researchers, "Graphic warning labels only work if one important condition is met: people have to be convinced that they can decrease the risk, and smokers are often not convinced that they can quit smoking."

The researchers conclude that, “Given the risk that people smoke more, and as long as there is no proof available showing that scary warning labels (and images in other countries) are effective, our advice would be to stop using them.

"More health benefits would be achieved if the areas currently reserved for warning labels would be used for a message to enhance efficacy or influence other determinants that have been found to play a role in ceasing smoking... Given the minimal, or even negative, effects we can expect from threatening communication, the potential of evidence- and theory-based communications on cigarette pack labels is promising."