A series of tests found that nicotine works differently on men's and women's brains. The study showed, however, that one of nicotine's major side effects was to make women's brains act more like men's. Previous studies have developed differences in cigarette use. For example, women take fewer and shorter puffs, have less success with nicotine replacement therapy, and are more affected by triggers that cause a desire to light up.
To determine the biological basis for the differences, the researchers tested 119 smokers and nonsmokers while their brain activity was being observed. When given the placebo patch, women generated more brain activity, compared with men. Areas with the most differences centered on mood, short-term memory, and task organization. The same results were not seen when the participants were given nicotine. The researchers found that brain metabolism dropped in women and rose in men. (The findings were reported in the International Journal of Neuropsychopharmacology, March 2005.)