A recent story in the New York Times suggested that abrupt changes in personality may be early warning signs for Alzheimer's disease. These changes in behavior can range from - agitation - to depression - to suddenly developing an overactive sexual appetite. It can set in even before the person starts to lose their memory.  To find out more - I spoke with Dr. Kenneth Kosik, co-director of the Neuroscience Research Institute at UC Santa Barbara. Dr. Kosik is the author of Outsmarting Alzheimer's, What You Can Do to Reduce Your Risk.