Caffeine and depression
Women who drank more caffeinated coffee experienced less depression, and the more coffee, the better the effects. Compared with women who drank little or no coffee, women who drank 2-3 cups a day had a 15% decreased risk for depression. Results were even better for women who drank more coffee. Women who drank at least 4 cups a day had a 20% decreased risk for depression. The positive results were seen only for caffeinated coffee intake. Neither decaf coffee, caffeinated tea, nor sugared soft drinks seemed to lower depression risk. Even chocolate didn’t do it.
Lucas M, Mirzaei F, Pan A, et al. Coffee, caffeine, and risk of depression among women. Arch Intern Med. 2011;171:1571-1578.