Let the coffee drinkers of the world rejoice. A recent study published in the Archives of Internal Medicine has discussed a positive relationship between caffeine and depression. This study looked at more than 50,000 women who were free from depression at the beginning of the study. This group was followed for 10 years to observe the relationship between caffeine and depression. Interestingly, those who drank 2 to 3 cups of caffeinated coffee a day had a 15 % decrease in depression, and those that drank 4 cups a day had a 20% decrease. Those who drank decaf coffee or other beverages with lower caffeine levels such as tea did not show the same association. The study also found that regular coffee drinkers were more likely to drink more alcohol, be current smokers and were less likely to be involved as volunteers or in community groups. They also had less obesity, fewer blood pressure issues and lower rates of diabetes.
The proposed relationship between caffeine and depression is as follows. Depression is caused by an inadequacy in 3 neurotransmitters, serotonin, dopamine and norepinephrine. A deficit in these neurotransmitters results in changes to brain chemistry thereby producing symptoms of depression such as decreased mood, motivation, activity level, sleep etc. The current thinking is that caffeine works on neurotransmitters dopamine and serotonin in the brain thereby mitigating the chemical changes caused by depression.
While we do know that some caffeine increases our alertness, enhances psychomotor performance, and let’s be honest makes people happy, we also know that too much caffeine can cause jitters, palpitations and insomnia. So while this study does bring some interesting possibilities to future mental illness research, it does not mean that we should all run out and overdose on Starbucks.