By Rebecca Jones

If you are like the millions of Americans whose day doesn’t start until the coffee maker is done dripping than according to a new study you might have a lower risk of depression than your non-caffeinated counter parts.

Caffeine is the most widely used stimulant in the world and coffee is its most popular vehicle; Americans alone spend almost 20 billion dollars on it annually. The health benefits of coffee consumption have always been a much debated topic and now thanks to research done by the Harvard School of Public Health there might be one more check in the “coffee is good for you” column.

According to the study, those that drink four or more cups of coffee a day are at a 20% lower risk of developing depression than those who drink little to no caffeine. Even drinking two to three cups a day, about the national average among coffee drinkers, was shown to reduce the incidence of depression by 15%. While researchers want to make it clear that they cannot prove that caffeine consumption could prevent or treat depression they do believe that there is a “dose-dependent” response. Those who drank the most coffee had the lowest incidence of depression.

To conduct their study, researchers questioned over 50,000 healthy women about their coffee drinking habits. All women were enrolled in the ongoing Nurses’ Health Study and had an average age of 63. Researchers went back 14 years into their history to acquire coffee drinking habits and then separated them into categories based on how much coffee they drank. They then continued to follow them for an additional 10 years so that they could get a long term view of chronic coffee consumption to base their findings on.

While this study specifically looked at coffee drinkers, researchers achieved similar results when looking at any type of caffeine consumption be it soft drinks or chocolate. They also referenced a small study conducted in Finland that found that men who drank the most coffee were less likely to commit suicide.

While scientists are unsure why there is a correlation between caffeine and depression one theory is that caffeine protects against certain neurotoxins. In animal studies research has shown that brain receptors in the basal ganglia, an area important for both depression and Parkinson’s, respond to caffeine and that perhaps that chronic stimulation may make these receptors more efficient.