Doctors Treat Brain Disorders As Mysteries Remain

UNDATED - David Elmore (L) and his identical twin brother Steven Elmore (R) pose before their brain scans in 1995 in the U.S. Doctors at the National Institute of Mental Health in Washington, DC, found that Steven, who has schizophrenia, has larger ventricles (the dark areas) and a smaller brain (less brain tissue overall) than his mentally healthy twin David. The brain, which makes us distinctly human, is unquestionably far more complex than any machine. It weighs about three pounds and is made up of delicate tissue containing billions of cells which regulate the body, learn to navigate the complicated world we live in, and hold a lifetime of memories. Although advances in science and medicine have improved treatment of common brain disorders, the brain still holds many mysteries. (Photo by Joe McNally/Getty Images)