In a report published online on October 14, 2009 in the American Journal of Clinical Nutrition
http://www.ajcn.org/, researchers from Tohoku University in Japan report that older people who frequently drink green tea have a significantly lower incidence depressive symptoms.

The study included 1,058 men and women aged 70 and older who resided in Sendai, Japan. Depression was evaluated using Geriatric Depression Scale scores, and dietary questionnaire responses were analyzed for the type and frequency of tea consumption. Blood samples were analyzed for C-reactive protein, a marker of inflammation.
Twenty-seven percent of the men and 29 percent of the women in the study were classified as experiencing mild and severe depressive symptoms, and 15 percent of the men and 24 percent of the women were categorized as having severe symptoms. Continue Reading
http://www.lef.org/newsletter/2009/1020_Older-Green-Tea-Drinkers-Less-Depressed.htm?source=eNewsLetter2009Wk42-3&key=Article&l=0#article