Frontotemporal Dementia: The One That Looks Like Something Else

Frontotemporal dementia: the one that looks like something else

A woman of 57 stops doing things. She sits. She watches television she previously disliked. She has stopped ringing her sister, stopped cooking, stopped noticing when the house needs attention. She eats enormous quantities of sweet food. She says blunt things about people’s weight in front of them and seems unbothered when they react.

Her GP treats her for depression. Her husband, worn down, consults a solicitor about separation. Her sister thinks she has become selfish.

Her memory is fine. She can tell you what she had for lunch, who the Prime Minister is, and where she was on her wedding day. Which is precisely why nobody considers dementia for three years.

This is behavioural-variant frontotemporal dementia, and the pattern above is close to textbook. FTD is one of the most common causes of dementia in people under 65, it presents with personality and behaviour change rather than memory loss, and it is misread as psychiatric illness, marital breakdown or character failure more reliably than any other condition we write about.

What FTD is

Frontotemporal dementia is a group of conditions caused by progressive degeneration of the frontal and temporal lobes. It is a different disease process from Alzheimer’s — different pathology, different distribution, different early symptoms — and it is not simply early Alzheimer’s.

It typically begins between the ages of about 45 and 65, which makes it a disease of working life rather than retirement. A substantial minority of cases are genetic, with an identified familial mutation, and genetic counselling is appropriate where there is a family history.

There are three main presentations.

Behavioural variant FTD (bvFTD)

The most common and the most misdiagnosed. The frontal lobes do most of what we experience as personality — inhibiting impulses, reading social situations, anticipating consequences, generating motivation, feeling empathy, monitoring our own behaviour — and bvFTD degrades exactly that.

The features:

Apathy. Loss of drive and initiation. The person stops doing things, does not start conversations, sits. This is not depression and it is not laziness, and it gets called both.

Loss of empathy. Emotional coldness, indifference to other people’s distress, failure to notice or care that something has landed badly. Families find this the hardest feature of any dementia, and it is frequently the first thing they report in retrospect.

Disinhibition. Saying the thing rather than thinking it. Tactless or cruel remarks. Inappropriate sexual comments or behaviour. Impulsive spending. Shoplifting, which brings some people into contact with police before they see a neurologist.

Compulsive and ritualistic behaviour. Fixed routines, hoarding, collecting, repetitive phrases, checking, a rigid insistence on doing things in one order.

Changes in eating. Markedly increased appetite, a strong preference for sweet food, eating non-food items, and sometimes drinking far more alcohol than before.

Loss of insight, usually profound. The person does not perceive that anything has changed, which is why they do not present to a doctor themselves and why they resist investigation.

Relatively preserved memory and visuo-spatial function early on, which is the diagnostic trap.

Primary progressive aphasia

Where language degenerates first, with other cognition relatively preserved for a period. Three subtypes are recognised, broadly:

Semantic variant — loss of word meaning. The person speaks fluently and grammatically and progressively loses knowledge of what words refer to. They may not recognise objects, and single-word comprehension fails.

Non-fluent / agrammatic variant — effortful, halting speech with grammatical errors and difficulty producing speech sounds, with comprehension of single words preserved.

Logopenic variant — slow, hesitant speech with word-finding pauses and difficulty repeating sentences. This one frequently turns out to be underlying Alzheimer’s pathology rather than FTD.

FTD with motor syndromes

FTD overlaps with several movement disorders — progressive supranuclear palsy, corticobasal syndrome, and motor neurone disease. The FTD–MND overlap matters clinically because it changes the trajectory significantly and because the cognitive change in MND is under-recognised.

Why it gets missed, and why it gets over-called

Two Australian studies published recently make an unusually honest pair, and together they explain why FTD diagnosis is genuinely hard rather than merely badly done.

The criteria are too narrow

Researchers at the University of Sydney, working through the FRONTIER frontotemporal dementia clinic, reviewed 110 patients over 14 years — described as the most comprehensive review of the bvFTD diagnostic criteria since they were set in 2011.

What they found:

• Nearly 90% of patients showed loss of empathy or apathy.
• Only 14.5% met the strict cognitive criterion, which requires preserved memory and visuo-spatial skills.
• Broadening the definition to include executive dysfunction raised the proportion meeting criteria to 73%.
• The number or combination of criteria met did not predict disease progression or survival.
• Average survival from symptom onset was 10.4 years, slightly shorter in women than men.

Read that second point again. The formal criteria require memory to be preserved — and only one in seven patients in a specialist FTD clinic actually satisfied that requirement. So a person can have frontotemporal dementia, be seen in the country’s leading clinic, and fail the checkbox because their memory is also affected.

The researchers recommend removing the requirement for preserved memory and visuo-spatial skills, adding social cognition as a core diagnostic feature, and developing more inclusive diagnostic tools for culturally and linguistically diverse populations.

And it is also over-suspected

The other side, and it is worth knowing because it explains why specialists are cautious.

A Mater Research study published in the European Journal of Neurology in January 2025 reviewed 100 consecutive referrals from psychiatrists, neurologists and geriatricians to the Mater Hospital Brisbane Memory and Cognitive Disorders Clinic, a tertiary service for atypical and young-onset dementias.

Of 100 patients referred with suspected or confirmed bvFTD, only 34 were true positives. Sixty-six were false positives — nearly 70% misdiagnosed.

The commonest reason was over-interpretation of neuroimaging and neuropsychological test results. The study also noted that patients often lack insight into their behavioural changes, that their symptom reports may be unreliable, and that psychiatric histories were frequently downplayed by both patients and informants.

So: bvFTD is both under-captured by the formal criteria and over-diagnosed in referrals, for related reasons. The behavioural presentation overlaps heavily with psychiatric illness in both directions, insight is impaired so the history is unreliable, and scans and cognitive tests are suggestive rather than definitive.

What follows practically for a family:

A suspected FTD diagnosis warrants a specialist cognitive clinic, not a single opinion. The misdiagnosis rate in that Mater series was from referrals by specialists.

A rejected FTD diagnosis is not necessarily the end, particularly if it was rejected because memory was affected. The Sydney work shows how many genuine cases fail that criterion.

Bring a reliable informant history, and be candid about psychiatric history rather than protective about it. Downplaying it makes the picture harder to read, not easier.

Ask what the alternative diagnosis is. “Not FTD” is not a diagnosis, and a person with a three-year behavioural change needs an explanation.

Getting it diagnosed

The pathway, and what to push for.

Start with the GP and ask for a referral to a cognitive neurologist, neuropsychiatrist or a specialist memory and cognitive disorders clinic — not a general geriatric assessment, which is calibrated for older people and Alzheimer’s-type presentations.

An informant history is the single most important diagnostic element. The person with bvFTD cannot give a reliable history because insight is impaired. The partner, sibling or adult child can, and the history should cover specific behavioural changes with approximate dates and examples. Write it before the appointment.

Neuropsychological assessment, mapping each domain — and in bvFTD, social cognition and executive function specifically, which standard batteries may not cover well.

Brain MRI, looking for frontal and temporal atrophy, with the caveat from the Mater study that over-interpretation of imaging is the commonest source of false positives. Early FTD can have normal-looking imaging.

FDG-PET in some centres, which can show frontal and temporal hypometabolism.

Blood tests and CSF to exclude other causes, and in some cases amyloid and tau biomarkers to distinguish Alzheimer’s pathology — particularly relevant for the logopenic aphasia variant.

Genetic testing and counselling where there is family history. This is a significant decision with implications for children and for insurance, and it should involve a genetic counsellor rather than being arranged casually.

Our general guide to the process is getting a dementia diagnosis.

Treatment and management

Honestly: there is no treatment that slows FTD, and some of the standard dementia drugs are wrong for it.

Cholinesterase inhibitors — donepezil, rivastigmine, galantamine — are not indicated in FTD and can worsen behaviour. If one has been prescribed on an assumption of Alzheimer’s disease and behaviour has deteriorated, that is worth raising. Memantine has not demonstrated benefit either.

SSRIs are the most commonly used medication and have some support for the behavioural features — disinhibition, compulsive behaviour, overeating, irritability.

Antipsychotics are sometimes used for severe behaviour and carry real risks, including in some cases heightened sensitivity. Where one is prescribed primarily to manage behaviour rather than treat a diagnosed psychiatric condition in an NDIS participant, it is chemical restraint with authorisation and reporting obligations attached. See behaviour support and restrictive practices.

Speech pathology matters a great deal in primary progressive aphasia — not to restore language, but to establish communication strategies and alternatives while the person can still learn them. Early referral is the thing; waiting until speech has gone wastes the window. Speech pathology sits at $193.99 per hour under the 2026–27 NDIS price limits.

Environmental and behavioural management is where the real gains are: structure, routine, removing triggers, managing access to food and money, and reducing demands. Changed behaviour and dementia covers the approach.

Occupational therapy at $193.99 per hour for functional assessment and environmental modification.

The specific practical problems

FTD produces difficulties that other dementias do not, and they need planning for.

Money. Impulsive spending, giving money away, responding to scams, and gambling are common and can be financially catastrophic. Act early: a limited-balance account for independent spending, a second signatory above a threshold, transaction alerts, removal of credit cards, and enduring power of attorney established while capacity is clearly intact. Done early this is straightforward; done late it becomes a tribunal application.

Food. Markedly increased appetite with a sweet preference leads to substantial weight gain, dental problems and diabetes risk, and sometimes to eating non-food items. Managing access rather than relying on instruction is the only approach that works — and where that involves locking food away for an NDIS participant, it is environmental restraint and requires a behaviour support plan and authorisation.

Police and legal contact. Shoplifting, public disinhibition and traffic offences occur. If this happens, put the diagnosis on the record in writing immediately and request a disability advocate — it changes how a matter is handled.

Driving. Risk judgment and impulse control go early, often before any obvious cognitive decline, which makes FTD particularly dangerous on the road. There is a legal obligation to notify the licensing authority. See driving, work and money.

Work. Most people with FTD are working when symptoms start and most lose that work through performance management before anybody knows why. Do not resign without advice — it frequently forfeits income protection and TPD cover held through superannuation.

The relationship. Loss of empathy is uniquely corrosive, because it removes the thing that makes a marriage feel like a marriage. Partners describe living with someone who is physically present and emotionally absent, and they describe being judged for struggling with it. This is not a failure of love and it needs support in its own right — Carer Gateway on 1800 422 737, and specialist counselling with someone who understands FTD rather than generic relationship therapy.

What families most need to hear

Three things that come up repeatedly and that nobody says early enough.

You were not imagining it. Families who live with early bvFTD spend years being told the problem is their perception, their marriage or their expectations. They are usually right that something changed, and they usually identified it long before any clinician. If you are two years into being disbelieved, keep going.

The cruelty is not deliberate. The remarks that land hardest — about weight, about appearance, about a death in the family — are produced by a damaged filter rather than by a changed opinion. That does not make them hurt less, and it does change what response makes sense. Correcting, explaining or appealing to the person’s better nature does not work, because the machinery that would respond to that appeal is the machinery that is degenerating.

Leaving is not a moral failure. FTD breaks relationships at a rate other dementias do not, because it removes empathy rather than memory. Partners who cannot continue are judged by people who have not lived with it. Support for the partner in their own right is not a luxury here.

Things that practically help

Structure and routine, because initiation is impaired and routine requires none.

Remove rather than restrict. Where impulsivity is the problem, taking the credit card out of the wallet works and asking the person not to use it does not.

Reduce the sensory and social load. Large gatherings reliably produce disinhibited behaviour; small, quiet, familiar settings do not.

Offer choices rather than instructions, which gets cooperation where a demand gets refusal.

Do not argue with a lack of insight. You are not arguing with a belief that evidence could change.

Keep a written record with dates. It is what diagnosis, NDIS applications and plan reassessments are built on, and nobody else is keeping it.

Find FTD-specific peer contact. Generic dementia groups, attended mostly by people thirty years older with memory-led presentations, do not fit. Dementia Australia and Young Dementia Australia can point you to younger onset and FTD-specific programs, and the National Dementia Helpline on 1800 100 500 is free and 24 hours.