Assessment of Cognitive Functioning Before and After Treatment With Duloxetine

The purpose of this study is to study the effect of duloxetine treatment on (1) cognitive functions, the brain mechanisms involved with thinking, reasoning, learning, and remembering; (2) psychosocial functions, how someone interacts with his/her social environment; and (3) the relationship between these two functions, in people who have major depressive disorder, a severe form of depression.