How is dementia diagnosed?

It is important to diagnose dementia early, as it allows for timely access to information and advice, medical management and support services. An early diagnosis also allows for future planning of care options, living arrangements and sorting of legal and financial affairs. However, early symptoms of dementia are often either not recognised, attributed to being a ‘normal’ part of ageing or may be denied by the person experiencing the symptoms, or by their family and carers. 

There is no single conclusive test available to diagnose dementia. As such, obtaining a diagnosis is also often a long process and involves comprehensive cognitive and medical assessments. The time taken to receive a confirmed diagnosis may also vary according to the person’s symptoms and who is conducting the assessments.

There is no single pathway to obtaining a diagnosis. However, a visit to a general practitioner (GP) is often the first step. According to the Clinical practice guidelines and principles of care for people with dementia in Australia, GPs are recommended to undertake an initial assessment for a person suspected of having dementia. This includes:

  • history taking from the person and if possible from a person who knows the person well (such as family members or carers)
  • cognitive and mental examination with a validated instrument (such as the Mini-Mental State Examination (MMSE), GP assessment of cognition (GPCOG), Rowland Universal Dementia Assessment Scale (RUDAS) for people from culturally and linguistically diverse backgrounds or the Kimberley Indigenous Cognitive Assessment (KICA-Cog) for Aboriginal or Torres Strait Islander people living in rural or remote areas)
  • physical examination and blood tests
  • brain imaging (where necessary)
  • review of current medication use
  • consideration of other causes, such as depression, delirium, thyroid disease or vitamin deficiency (Guideline Adaptation Committee 2016).

If dementia is a suspected diagnosis, the clinical guidelines state that best practice is for GPs to make a referral to memory assessment specialists (such as geriatricians or psycho-geriatricians) or services (such as memory clinics) for a comprehensive assessment. The aim of the comprehensive assessment is to gather information about changes in behaviour, functional capacity, psychosocial issues and relevant medical conditions to allow for a diagnosis to be made.

While diagnosing health conditions is not the main function of aged care assessments undertaken for people seeking entry to or currently using aged care services, dementia may be diagnosed during medical assessments by Aged Care Assessment Teams, if this impacts care needs.

Progression of dementia

Symptoms of dementia vary from person to person, and for individuals, from day to day. There are also particular symptoms associated with certain types of dementia. However, in all cases the progressive nature of dementia will eventually result in cognitive and physical decline. The rate of decline will vary due to personal characteristics (age, number and type of other co-existing conditions), type and severity of dementia, age at diagnosis and the person’s environment (such as care and living arrangements and access to health services).

Due to the variations in symptom presentation and progression, there are many models used to classify dementia severity. However dementia progression can often be grouped into 3 stages (mild, moderate and advanced dementia).

Mild dementia

Mild dementia is defined by cognitive impairment and poor performance on objective cognitive assessments that represent a decline from the past. However, as opposed to more severe forms of dementia, the person retains independence in basic activities of daily living.

The onset of symptoms may be gradual and can include:

  • forgetfulness and confusion
  • irritability and appearing more apathetic
  • poor judgement and decision making
  • disinterest in activities
  • vision or speech problems
  • behavioural changes
  • a decline in higher order or more complex activities of daily living such as understanding finances, planning, and organisation.

As signs are subtle, dementia may not be recognised or instead be attributed to old age.

Moderate dementia

Symptoms in this stage are more distinct and impact on instrumental activities of daily living such as driving and preparing meals. In addition to the symptoms in mild dementia, symptoms for moderate dementia may include:

  • increased forgetfulness and confusion
  • inappropriate or uncharacteristic behaviours
  • increased fear and paranoia.

These experiences often cause distress for the person with dementia, and their family and friends.

Advanced dementia

This is the final stage in which health and functional ability decline and the person becomes dependent on others for activities of daily living (for example dressing, bathing and toileting).

The person may experience:

  • severe memory loss
  • problems with communication
  • difficulty swallowing
  • incontinence
  • decreased mobility or complete immobility in the final months or weeks of life.

Most people in advanced stages of dementia require extensive care, often from permanent residential aged care services.