Dementia is a major neurocognitive disorder (NCD) that affects millions of people in the United States (American Psychiatric Association [APA], 2013). However, dementia is not a particular disease syndrome. Rather it is a descriptor that explains an array of symptoms. Generally, these describe progressive cognitive decline and performance levels in everyday activities. Healthcare professionals often describe the progression of dementia in stages. Occupational therapists and other rehabilitation professionals provide key expertise when it comes to dementia assessment.
Related: Best Practice: Dementia Assessment and Staging
Stages of dementia
The Alzheimer’s Association broadly describes the progression of Alzheimer’s dementia by three stages:
- Early or mild
- Middle or moderate
- Late or severe
In early-stage dementia, a person may function independently yet begin to experience problems with memory or forgetfulness. These symptoms may not be apparent to the public, but something that is initially observed by close friends and family members.
In middle-stage dementia, the dementia symptoms are more noticeable such as confusion, memory problems, and changes in personality and mood. In the middle stage, individuals begin to require assistance with everyday activities. They rely more heavily on caregivers.
In late-stage dementia, the symptoms are severe. Individuals require 24/7 assistance with daily activities. Eventually they require assistance for walking and lose the ability to control basic life functions such as communicating and swallowing.
Global deterioration scale
More detailed staging guidelines can be helpful in describing how symptoms can change through the disease progression. The Global Deterioration Scale (GDS) was developed by Dr. Barry Reisberg and colleagues to provide a set of language and guidelines to describe decline in cognition, function and care needs of persons with dementia. The GDS depicts seven levels of dementia.
GDS levels and characteristics
| GDS Level | Characteristics |
| Stage 1: No Cognitive Decline | No complaints or evidence of memory deficit |
| Stage 2: Very mild cognitive decline. Also referred to as age-associated memory impairment | Subjective complaints of memory deficits; forgetfulness, yet deficits not noticeable to informal observation Independent in activities of daily Living (ADL) and can self-correct mistakes; may misplace familiar objects |
| Stage 3: Mild Cognitive Decline (or Mild Cognitive Impairment) | Early confusional state; memory deficits which become more apparent to others Complex tasks become more challenging, may start to have difficulty with IADL (instrumental daily activities; like meal preparation, finances, home management etc.) |
| Stage 4: Moderate Cognitive Decline or Mild Dementia | Late confusional state; memory and safety deficits obvious, may also appear depressed, disinterested and withdrawn Overwhelms easily; Clear-cut deficits during clinical interviews |
| Stage 5: Moderately Severe Cognitive Decline or Moderate Dementia | Requires frequent redirection, wanders or “sun-downing” Basic word-finding difficulties more apparent, difficulty recalling personal major relevant events i.e. anniversary, birthdates etc. Able to self-feed and perform toileting by self with might require assistance to choose appropriate clothing |
| Stage 6: Severe Cognitive Decline or Moderately Severe Dementia | Functional communication impaired Forgetful of family member names Unaware of recent events and surroundings Requires assistance for ADL and mobility, may become incontinent Personality and emotional changes will occur (i.e. delusions, agitation etc.) High fall risk |
| Stage 7: Very Severe Cognitive Decline or Severe Dementia | Total care required, basic motor skills are lost, often bedbound Non-verbal yet may demonstrate visual tracking with eyes; trouble swallowing (dysphagia) Aspiration risk |
Predementia and dementia assessment
GDS stages 1-3 are generally considered pre-dementia stages, where stages 4-7 are dementia stages. As a healthcare provider, the GDS can be useful to track how dementia symptoms progress, as well as support care planning for the patient and family to provide greater context for caregiving needs. Due to the impact to physical and functioning and cognition, the dementia staging process is led by an interprofessional team.
For instance, speech-language pathologists can help assess and provide intervention to address communication and language domains. Occupational therapy practitioners can help assess changes in occupational performance levels with ADLs/IADLS and physical therapy professionals can help address changes in ambulatory abilities. Neuropsychologists are also instrumental to help support behavioral symptomology.
Progression of dementia symptoms
Although there are specific staging guidelines, understand that dementia affects every person differently. In most cases, individuals live around 4–8 years after receiving the diagnosis. However, others may live 20 years after their initial diagnosis.
Various factors can impact the progression of symptoms, such as the type of dementia, and age during diagnosis. Other comorbidities include vascular conditions like hypertension or mood disorders like depression. As with most neurological conditions, early identification and intervention are key to provide optimal and high-quality care to the patient and family.
References
- Alzheimer’s Association. (n.d). Stages of Alzheimer’s. https://www.alz.org/alzheimers-dementia/stages
- American Psychiatric Association. (2013). Diagnostic and statistical manual of mental disorders (5th ed.). Washington, DC: Author.
- Reisberg, B., Ferris, S.H., Leon, M.J., et al. (1982). The global deterioration scale for assessment of primary degenerative dementia. American Journal of Psychiatry. 139, 1136-1139
