There are varying opinions on how many stages and what those stages entail of this disease. To date, the most widely accepted theory of this comes from Dr. Barry Reisberg. In 1982, he published an article in the American Journal of Psychiatry that describes the stages of Alzheimer's disease.

Stage 1

No cognitive decline evident on interviews. No complaints of memory loss.

Stage 2

Very mild cognitive decline (forgetfulness). Subjective complaints of memory deficit, most frequently forgetting where one has placed familiar objects or forgetting names one formerly knew well. No visible evidence of memory loss on clinical interview. No visible memory loss in employment or social situations.

Stage 3

Mild cognitive decline (early confusion). Earlier clear-cut memory loss. Can occur in more than one of the following areas.:

1. patient gets lost when traveling to an unfamiliar location;

2. coworkers become aware of patient's relatively low performance;

3. inability to formulate appropriate words and names become evident to intimates;

4. patient may read a passage of a book and retain relatively little material;

5. patient may demonstrate decreased ability on remembering names upon introduction to a new

people;

6. patient may have lost or misplaced an object of value;

7. inability to concentrate may be evident on clinical testing. Objective evidence of memory deficit obtained only with an intensive interview. Denial begins to become manifest in patient. Mild to moderate anxiety accompanies symptoms.

Stage 4

Moderate cognitive decline (Late Confusion). Clear-cut deficit on careful clinical interview. Memory loss can occur in following areas:

1. decreased knowledge of current and recent events;
2. may exhibit some deficit in memory of one's personal history;
3. concentration deficit elicited on serial subtractions;
4. decreased ability to travel, handle finances, etc.

Frequently no deficit in the following areas:

1. orientation to time and person;
2. recognition of familiar persons and faces;
3. ability to travel to familiar locations.
Inability to perform complex tasks. Denial is dominant defense mechanism. Flattening of affect and withdrawal from challenging situations occur.

Stage 5

Moderately severe cognitive decline (Early Dementia). Patient can no longer survive without some assistance. Patient is unable during interview to recall a major relevant aspect of their current lives, e.g., an address or telephone number of many years, the names of close family members, the name of the high school or college from which they graduated. Frequently some disorientation to time (date, day of week, season, etc.) or to place. An educated person may have difficulty counting back from 40 by 4s or from 20 by 2s. 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 going to the bathroom and eating, but may have some difficulty choosing the proper clothing to wear.

Stage 6

Severe cognitive decline (Middle Dementia). May occasionally forget the name of the 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 familiar locations. Diurnal rhythm frequently disturbed. Almost always recall their own name. Frequently continue to be able to distinguish familiar from unfamiliar persons in their environment. Personality and emotional changes occur. These are quite variable and include:

1. delusional behavior, e.g., patients may accuse their spouse of being an impostor, may talk to imaginary figures in the environment, or to their own reflection in the mirror;
2. obsessive symptoms, e.g., person may continually repeat simple cleaning activities;
3. anxiety agitation, and even previously nonexistent violent behavior may occur;
4. loss of willpower because an individual cannot carry a thought long enough to determine a purposeful course of action.

Stage 7

Very severe cognitive decline (Late Dementia). All verbal abilities are lost. Frequently there is no speech at all - only grunting. Incontinent of urine, requires assistance going to bathroom and feeding. Lose basic psychomotor skills, e.g., ability to walk, sitting and head control. The brain appears to no longer be able to tell the body what to do. Generalized and cortical neuralgic signs and symptoms are frequently present.
(Adapted from Reisberg, B., Ferris, S.H., Leon, J.J. & Crook, T. The global deterioration scale for the assessment of primary degenerative dementia. American Journal of Psychiatry, 1982.)