P1‐315: PREVALENCE OF DIAGNOSED SYMPTOMS PRECEDING ALZHEIMER'S DISEASE DIAGNOSIS AMONG TREATED AND UNTREATED ALZHEIMER'S DISEASE PATIENTS WITH COMMERCIAL AND MEDICARE SUPPLEMENTAL INSURANCE. (1st July 2006) - Black, Christopher M.; Lipton, Richard B.; Thiel, Ellen; Brouillette, Matthew; Khandker, Rezaul Karim