The Global Deterioration Scale (GDS) assesses the severity of primary degenerative dementia and delineates stages of cognitive decline.
1. No cognitive decline
No subjective complaints of memory deficit. No memory deficit evident on clinical interview.
2. Very mild cognitive decline
Subjective complaints of memory deficit, most frequently in following areas: (a) forgetting location of objects; (b) forgetting familiar names. No objective evidence of memory deficit on clinical interview or in employment or social situations. Appropriate concern with respect to symptomatology.
3. Mild cognitive decline
Earliest clear-cut deficits. Manifestations in more than one of the following areas: (a) patient may have gotten lost when traveling to an unfamiliar location; (b) co-workers become aware of patient’s relatively poor performance; (c) work- and name-finding deficit becomes evident to intimates; (d) patient may read a passage or a book and retain relatively little material; (e) patient may demonstrate decreased facility in remembering names upon introduction to new people; (f) patient may have lost or misplaced an object of value; (g) concentration deficit may be evident in clinical testing.
4. Moderate cognitive decline
Clear-cut deficit on careful clinical interview. Deficit manifest in the following areas: (a) decreased knowledge of current and recent events; (b) may exhibit some deficit in memory or personal history; (c) concentration deficit elicited on serial subtractions; (d) decreased ability to travel, handle finances, etc. Frequently no deficit in following areas: (a) orientation to time and person; (b) recognition of familiar persons, and places; (c) ability to travel to familiar locations; (d) inability to perform complex tasks. Denial is dominant defense mechanism. Flattening of affect and withdrawal from challenging situations occur.
5. Moderately severe cognitive decline
Patient can no longer survive without some assistance. Patient is unable during interview to recall a major relevant aspect of his or her current life (e.g., an address or telephone number of many years; the name of close family members such as grandchildren; the name of the high school or college from which he or she graduated). Frequently some disorientation to time (date, day of the week, season, etc.) or to place. An educated person may have difficulty counting back from 40 by 4’s or from 20 by 2’s. Persons at this stage retain knowledge of many major facts regarding themselves and others. They invariably know their own names and generally know their spouse’s and children’s names. They require no assistance with toileting and eating but may have some difficulty choosing the proper clothing to wear and may occasionally clothe themselves improperly (e.g., put shoes on the wrong feet).
6. Severe cognitive decline
May occasionally forget the name of a spouse upon whom they are entirely dependent for survival. Will be largely unaware of all recent events and experiences in their lives. Retain some knowledge of their past lives, but this is very sketchy. Generally unaware of their surroundings, the year, the season, etc. May have difficulty counting from 10 both backward and sometimes forward. Will require some assistance with activities of daily living (e.g., may become incontinent), will require travel assistance but occasionally will display ability to travel to familiar locations. Diurnal rhythm frequently disturbed. Almost always recall own name. Frequently continue to be able to distinguish from unfamiliar persons in their environment. Personality and emotional changes occur. These are quite variable and include: (a) delusional behavior (e.g., patients may accuse spouse of being an impostor; may talk to imaginary figures in the environment or to their own reflection in the mirror); (b) obsessive symptoms (e.g., person may continually repeat simple cleaning activities); (c) anxiety symptoms, agitation, and previously nonexistent violent behavior may occur; (d) cognitive abulia (i.e., loss of willpower because an individual cannot carry a thought long enough to determine a purposeful course of action).
7. Very severe cognitive decline
All verbal abilities are lost. Frequently there is no speech at all—only grunting. Incontinent of urine; requires assistance toileting and feeding. Loose basic psychomotor skills (e.g., ability to walk). The brain appears to no longer be able to tell the body what to do. Generalized and cortical neurological signs and symptoms are frequently present.
Reisberg, B., Ferris, S. H., de Leon, M. J., & Crook, T. (1982a). The Global Deterioration Scale for Assessment of Primary Degenerative Dementia. The American Journal of Psychiatry, 139, 1136–1139.
PMID: 7114305 DOI: 10.1176/ajp.139.9.1136