The Global Deterioration Scale (GDS)—developed by Dr. Barry Reisberg, Director of the Fisher Alzheimer’s Disease Education and Research program at NYU Grossman School of Medicine—is a guideline used worldwide to identify which of the seven Alzheimer’s stages an individual with this condition is in. The scale consists of seven Clinical Stages; stages 1-3 are pre-dementia while 4-7 are dementia stages. Stage 5 marks when someone can no longer live independently without assistance.
Stage 1: No Dementia Seen
Stage 1, or normal, is defined as those individuals who do not display any objective or subjective signs of cognitive and functional decline, along with related behavioral and mood changes at any age. These people are considered to be mentally healthy.
Stage 2: Subjective Memory Loss
Subjective cognitive decline (SCD) is a condition affecting many people over the age of 65, in which they experience difficulty with memory and/or functioning. Those affected report that their memories are not as sharp as they were 5 or 10 years ago; also common are difficulties locating items recently placed by oneself.
Stage 3: Mild Cognitive Impairment
People with Mild Cognitive Impairment (MCI) may present signs that can be observed by those around them. Such indications could include asking the same questions repeatedly, difficulty mastering new skills such as computer use, weakness in planning social activities like dinner parties, and developing concentration issues along with increased anxiety.
Stage 4: Moderate Cognitive Decline
At stage 4 of Alzheimer’s Disease, there is an increased difficulty in managing instrumental (complex) daily life activities such as paying bills and shopping independently. Memory loss also becomes more obvious with a decreased ability to recall recent events or even the date/season. Despite these deficits, individuals may still be able to live independently in their community setting but will often display signs of emotional flatness and withdrawal due to denial about their condition.
Stage 5: Moderately Severe Cognitive Decline
In this stage of Alzheimer’s Disease, deficits are severe enough to prevent independent living in the community. People with Alzheimer’s may forget what clothing is appropriate for the weather or normal circumstances and wear the same outfit without being reminded. This stage typically lasts 1.5 years, during which people need assistance with food, rent payments, and other finances as they can no longer manage on their own; if not supported properly they may become angry or suspicious of others.
Stage 6: Severe Cognitive Decline
At the sixth stage of Alzheimer’s Disease (AD), individuals often have difficulty remembering recent events such as who is their national leader or other prominent figures. They may not recall which schools they attended and even basic life information like the names of their parents, former occupations, or place of birth can be foggy. Though they still know their name at this point it is possible to mistake identities – especially family members. Cognitive ability also suffers greatly leaving them unable to count backward from 10 consecutively by 1s.
Stage 7: Very Severe Cognitive Decline
At the final stage of AD, individuals require round-the-clock support with everyday activities. This seventh stage is divided into six distinct functional substages that span approximately 4 and a half years. During Stage 7a, speech becomes limited to only a few intelligible words or less. As this part progresses (Stage 7b), they are left with one word at most being comprehensible; also losing their capability for independent ambulation due to physical disability, poor caregiving practices, or medication side effects in some cases but can be delayed by excellent healthcare during this time frame. After about 1 year on average comes Stage 7c where even basic motor skills diminish along with any remaining verbal ability resulting in them not being able to stay upright unless armrests are present when seated – finally leading up to complete loss of mobility as well as sitting capabilities after another estimated year (7d).