CLINICAL STAGES OF NORMAL AGING AND ALZHEIMERS-DISEASE - THE GDS STAGING SYSTEM

Phenomenologic, cross-sectional and longitudinal studies have resulted in the identification of characteristic stages of normal aging and pr ogressive Alzheimer's disease (AD). A staging system resulting from th ese studies is known as the ''GDS Staging System.'' Three optimally co ncordant and potentially independent clinical rating instruments are i ncorporated in this staging system, the Global Deterioration Scale (GD S), the Brief Cognitive Rating Scale (BCRS) and the Functional Assessm ent Staging measure (FAST). Definitions of each of the elements of thi s staging system as well as reliability and concurrent validity data h ave been published. Clear advantages of the GDS Staging System over ot her available staging measures include: (1) readily interpretable and clinically meaningful stages and substages; (2) improved definition of the boundaries of normal aging and incipient AD, and (3) the ability to chart the course of the severely impaired, conventionally ''untesta ble,'' portion of AD. Widespread usage of this staging system can pote ntially advance current research and clinical understanding of normal brain aging and the nature, course and treatment of AD and related con ditions.