Protective Effects of Caffeine and Coffee Constituents in Inflammatory Models of Depression

Abstract

Caffeine is the most widely used compound that exerts a pharmacological effect on the central nervous system and is found most predominantly in coffee. It has been well established that coffee has a beneficial effect on numerous disease states including depression. A number of prospective and cohort studies have shown the benefit of coffee in preventing episodes of depressive symptoms. Studies indicate that the amount of coffee consumed is important with studies showing that moderate intake of caffeinated coffee may be beneficial in decreasing the risk of developing symptoms of clinical depression. It has however been shown that high consumption of coffee increases the risk of depression and suicide. It appears that caffeine in combination with other constituents of coffee may be required to show the antidepressant activity. To date very few studies have been undertaken to evaluate components of coffee for their antidepressant effects and no studies have been undertaken assessing these compounds in combination with caffeine and their subsequent effects on symptoms of depression. Over the last 50 years there have been countless proposed hypotheses of depression many of which are flawed including the well-accepted monoamine theory of depression. As a result of the shortcomings identified in this theory, numerous newer theories of depression have been proposed in recent times.