A patient guide · memory and thinking changes
When memory changes,
what happens next?
Dementia is not one single illness. This guide explains how it may present, how clinicians investigate it, and where newer blood tests may fit.
Understanding
dementia
assessment pathway
dementia
assessment pathway
For education and discussion with your healthcare professionalInformation current to June 2026
Thinking and memory changes
1 / 8
01 · What dementia can look like
It is more than occasionally forgetting a name
Look for change over time
and its effect on everyday life
and its effect on everyday life
Possible changes include
- Memory: repeating questions, forgetting recent conversations or appointments
- Language: difficulty finding words or following a conversation
- Planning: trouble managing finances, medicines, cooking or familiar tasks
- Orientation: getting lost or becoming confused about time or place
- Visuospatial skills: difficulty judging distance or navigating
- Behaviour or personality: apathy, irritability, disinhibition or withdrawal
Dementia is a syndrome.
Different diseases can cause it, including Alzheimer’s disease, vascular cognitive impairment, Lewy body dementia and frontotemporal dementia.
Different diseases can cause it, including Alzheimer’s disease, vascular cognitive impairment, Lewy body dementia and frontotemporal dementia.
Ask: is it affecting independence?
Missing an occasional word is common. A persistent decline that interferes with normal activities deserves assessment.
Symptoms can overlap and may have treatable contributorsEarly assessment can clarify options and support
Recognising possible dementia
2 / 8
02 · The first step
Start with a conversation and a clinical assessment
Bring someone who knows you well
if you are comfortable doing so
if you are comfortable doing so
1HistoryWhat changed? When did it begin? Is it getting worse?
2FunctionWhich daily activities, work or driving tasks are affected?
3ExaminationGeneral, neurological, mood, hearing and vision assessment.
4Cognitive testingA brief test can measure domains and establish a baseline.
5PlanInvestigate, review results, support safety and arrange follow-up.
Useful information to bring
- Examples of changes and dates
- Medication and supplement list
- Recent falls, driving or safety concerns
- Sleep, mood, alcohol and medical history
Do not wait for a crisis.
Sudden confusion over hours or days is more consistent with delirium or another acute problem and needs prompt medical attention.
Sudden confusion over hours or days is more consistent with delirium or another acute problem and needs prompt medical attention.
A GP can begin the assessment and coordinate next stepsUrgent change ≠ routine dementia assessment
The assessment begins with the person, not a scan
3 / 8
03 · Looking for other explanations
Many contributors can mimic or worsen memory problems
Some are treatable
and should be checked early
and should be checked early
Common checks may include
- Medication effects, alcohol and substance use
- Depression, anxiety, grief and poor sleep
- Hearing and vision impairment
- Thyroid disease, vitamin deficiency and other metabolic problems
- Sleep apnoea, pain and systemic illness
- Vascular risk factors and prior stroke
Routine investigations
| Blood tests | Chosen to look for reversible or contributing causes |
| Brain imaging | Often CT or MRI, depending on the situation |
| Follow-up | Review results and assess progression over time |
A normal routine blood panel does not rule out dementia.
It helps exclude other problems and contributes to a complete assessment.
It helps exclude other problems and contributes to a complete assessment.
Testing is tailored to the person, symptoms and examinationNot every test is needed for every patient
Exclude contributors and alternatives
4 / 8
04 · Specialist investigations
Sometimes the pathway needs more specific evidence
Usually after clinical assessment
and often with specialist input
and often with specialist input
Possible next investigations
| MRI or CT | Structure: stroke, tumour, hydrocephalus or atrophy patterns |
| Neuropsychology | Detailed profile of memory and thinking abilities |
| CSF biomarkers | Obtained by lumbar puncture in selected cases |
| Amyloid PET | Shows amyloid pathology in the brain |
Medicare note: amyloid PET
Specialised imaging such as amyloid PET is MBS-funded only when ordered by an eligible specialist and when the relevant MBS criteria are met. A GP request alone does not make it Medicare-funded.
Specialised imaging such as amyloid PET is MBS-funded only when ordered by an eligible specialist and when the relevant MBS criteria are met. A GP request alone does not make it Medicare-funded.
Why confirm?
Knowing the likely disease process can improve diagnostic confidence, guide support and, in selected settings, inform consideration of disease-modifying treatments.
Access and funding depend on the test, provider and clinical criteriaAsk the ordering clinician about likely costs before proceeding
When more specific testing is needed
5 / 8
05 · The new blood test
p-Tau181: a blood-based clue about Alzheimer’s pathology
Standard blood collection
not a stand-alone diagnosis
not a stand-alone diagnosis
What is tau?
Tau is a normal nerve-cell protein. In Alzheimer’s disease, abnormal phosphorylation of tau is associated with the disease process.
p-Tau181 is a phosphorylated form measured in plasma. It is associated with amyloid-related Alzheimer’s pathology and neurodegeneration.
The intended role is mainly “rule-out”.
A negative result is associated with a low likelihood of significant Alzheimer’s-related amyloid pathology in the validated symptomatic age group.
A negative result is associated with a low likelihood of significant Alzheimer’s-related amyloid pathology in the validated symptomatic age group.
p-Tau181
A biomarker, not a diagnosis
- Best interpreted in adults aged 55–80 with cognitive impairment or decline
- Interpret alongside history, cognitive testing and examination
- A positive result needs further investigation
Looking ahead
SNP reports that p-Tau217 has shown greater diagnostic accuracy in several studies and is expected to become available through SNP in late 2026.
Current SNP assay: Roche Elecsys® p-Tau181 · TGA approvedBiomarker field is evolving rapidly
Understanding p-Tau181
6 / 8
06 · What the result can mean
The result changes the next question — it does not end the assessment
Always interpret in context
with your treating clinician
with your treating clinician
Negative p-Tau181
Lower likelihood of amyloid pathologyThis makes significant Alzheimer-related amyloid pathology less likely in the appropriate clinical setting.
Next: continue reviewing other causes, including vascular cognitive impairment, Lewy body dementia, frontotemporal dementia, depression and anxiety.
Positive p-Tau181
Higher likelihood of amyloid pathologyThis does not diagnose Alzheimer’s disease by itself.
Next: referral to an Alzheimer’s/dementia specialist to consider confirmation with CSF analysis or amyloid PET, where appropriate.
Important limitations: kidney impairment can increase p-Tau181 concentrations. Results outside the validated age range, or results that do not fit the clinical picture, need cautious interpretation.
Negative ≠ “nothing is wrong” · Positive ≠ diagnosis on its ownAsk what action will follow before having the test
Interpreting the blood test
7 / 8
07 · Cost and take-home message
A useful test when it answers a clear clinical question
Discuss whether it will change management
$400
Quoted SNP fee at time of collection*
| Medicare rebate | None |
| Sample | Standard blood test at SNP locations |
| Request | p-Tau181 on a standard request form |
| Turnaround | Within 7 days from specimen receipt |
Before testing, ask:
What does my clinician think is causing the symptoms? What will a negative or positive result change? Will specialist confirmation be needed?
What does my clinician think is causing the symptoms? What will a negative or positive result change? Will specialist confirmation be needed?
The pathway in one line
Notice change → see your GP → assess cognition and function → check contributors → consider specialist tests → make a shared plan.
*SNP document: cost current at publication, June 2026Costs and availability may change — confirm before collection
Discuss your next step with your GP
8 / 8