McLaughlin T, Feldman H, Fillit H, Sano M, Schmitt F, Aisen P, Leibman C, Mucha L, Ryan JM, Sullivan SD, Spackman DE, Neumann PJ, Cohen J, Stern Y. Dependence as a unifying construct in defining Alzheimer’s disease severity. Alzheimers Dement. 2010 Nov;6(