Cigarette pack warnings that remind smokers of the fatal consequences of their habit may actually make them smoke more as a way to cope with the inevitability of death, according to researchers.

A small study by psychologists from the United States, Switzerland and Germany showed that warnings unrelated to death, such as "smoking makes you unattractive" or "smoking brings you and the people around you severe damage," were more effective in changing smokers' attitudes toward their habit.

This was especially the case in people who smoked to boost their self-esteem, such as youth who took up the habit to impress or fit in with their peers and others who thought smoking increased their social value, the researchers said.

"In general, when smokers are faced with death-related anti-smoking messages on cigarette packs, they produce active coping attempts as reflected in their willingness to continue the risky smoking behavior," the study said.

"To succeed with anti-smoking messages on cigarette packs one has to take into account that considering their death may make people smoke."

The study was based on 39 psychology students, aged between 17 and 41, who said they were smokers.

Participants filled in a questionnaire to determine how much their smoking was based on self-esteem, were then shown cigarette packs with different warnings on them, and then after a 15-minute delay, the students were asked more questions about their smoking behavior that included if they intended to quit.

"One the one hand, death-related warnings were not effective and even ironically caused more positive smoking attitudes among smokers who based their self-esteem on smoking," the study said.

"On the other hand, warning messages that were unrelated to death effectively reduced smoking attitudes the more recipients based their self-esteem on smoking."

The researchers said this finding can be explained by the fact that warnings such as "smoking makes you unattractive" may be particularly threatening to people who believe that smoking makes them feel valued by others or boosts their self-image.