In 1998, researchers at the University of Arizona conducted a double-blind study of the effectiveness of acupuncture on depression. The results demonstrated a dramatic decrease in symptoms in more than half of the women tested. More specifically, seventy percent of the women in the study experienced a fifty percent reduction in noticeable symptoms of depression. The study lasted for two months. During this time, each patient was given twelve acupuncture sessions with the bulk of them received during the first month of treatment. The patients were assigned to one of three groups. The first received immediate acupuncture for depression. The second group received acupuncture treatment for non-specific reasons, and the third group was wait-listed for eight weeks then treated with acupuncture for depression.