Scientists Seek to Redefine Schizophrenia

Walk through the streets of almost any big city in California, and you're likely to encounter homeless people suffering from schizophrenia. The symptoms -- disturbing hallucinations and delusions -- are frightening and obvious. And yet we know almost nothing about the biology of schizophrenia. There's no blood test for it, and no scan that can diagnose it. In the second of a three-part series on schizophrenia, we meet scientists who are redefining the disease and proposing new treatments.