Even light smoking can make people grumpy and less able to handle stress, according to a recent British study.
New Zealand anti-smoking lobby group Action on Smoking and Health (ASH) said the study, published in the June edition of the journal Pharmacology, Biochemistry and Behaviour, dispelled the myth that smoking hada calming effect.
Researchers from London's King's College, in their study called Mood Differences Between Male And Female Light Smokers And Non-smokers, subjected two groups to "a battery of cognitive tests that were mildly stressful".
Males and females who smoked between five and 12 cigarettes a day were tested immediately after smoking.
The second group were male and females who were non-smokers.
The two groups were equivalent in age, intellect, personality measures, and levels of anxiety and depression.
The researchers found the smokers' group was "overall significantly more discontented, troubled, tense, quarrelsome, furious, impatient, hostile, annoyed and disgusted and experienced greater dizziness".
After cognitive tests, "both male and female smokers showed greater increases than non-smokers in feeling spiteful, rebellious, incompetent".
They also exhibited greater sweating, "suggesting that they experienced greater mood changes in response to cognitive stress".
There was no apparent difference between the two groups for divided or sustained attention tasks or in episodic memory.
The researchers said it was unlikely nicotine withdrawal symptoms had caused the tension in smokers.
