Smoking to relieve stress is nothing new, but now a brain imaging study shows just how nicotine can blunt our anger response.

People who received half a nicotine patch dose proved less likely to rise to provocation, compared to when they took a placebo. This may support the idea that angry or stressed-out individuals can more easily become addicted to cigarettes, researchers say.

"The findings suggest that people in anger provoking situations may be more susceptible to the effects of nicotine," said Jean Gehricke, a psychiatry researcher at the University of California in Irvine.

This also represents the first study to identify a brain system that is most reactive to nicotine and has the strongest connection with anger response, Gehricke told LiveScience.

To test this, the study pitted a group of nonsmokers against a nonexistent game opponent whose "behavior" was designed to irritate and provoke. The simple computer game involved a race to see who could click a mouse button fastest in response to seeing a red square appear.

The twist – players in the game could set punishments where the loser would have to hear a blast of white noise over headphones. Winners could set the intensity and duration of the annoying sound, but players could also see what the other person had set as a punishment level.

Researchers who controlled the fake opponent gradually raised the punishment level for the study participants. That translated into an open invitation for people to retaliate by raising punishment levels for the nonexistent player, but people on the nicotine patch were less easily provoked and inflicted shorter punishment than those who took a placebo.

Turns out that the nicotine targets a system of the brain focused on regulating emotion, known as the limbic cortex. PET scans showed increased brain activity in those brain regions for people on the patch.

Such calming effects of nicotine may act as an anger management crutch for people who tend to be angrier, researchers suggest – or for people suffering from high amounts of stress at work or at home.

Whether smoking actually does much to relieve stress in real life remains a bit murkier. A Pew Research Center study earlier this month found that half of smokers say they "frequently" experience daily stress, compared to just 35 percent of former smokers and 31 percent of people who never smoked.

The same Pew research found that smokers were less happy and less healthy than both non-smokers and quitters, although that does not address the cause of such unhappiness.

But in the long run, smoking boosts the risk of vascular diseases that lead to heart attacks and stroke, which kill more smokers than all cancers combined. And second-hand smoke has proven as deadly for pets as it is for human partners.

The full study is detailed online in this week's issue of the journal Behavioral and Brain Functions.

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