Most coffee drinkers say they function better after their first cup of the day.
Some people fear they grow dependent on drinks containing the chemical.
The study suggests this is unlikely, although the finding runs contrary to previous research. The new research is being presented at a national meeting of the American Chemical Society, which claims to be the world's largest scientific society. She said that at doses of one to three cups of coffee a day, caffeine has no affect on the area of the brain involved with addiction, dependence and reward. She recently completed a study with laboratory animals. It confirmed what any coffee drinker could tell you - that caffeine consumed in moderation contributes to increased alertness and energy.