Behavioural Variant Frontotemporal Dementia (bvFTD)

Behavioural variant frontotemporal dementia (bvFTD), also spelled behavioral variant FTD, is the most common type of frontotemporal dementia. It accounts for around two in every three people diagnosed with FTD. Damage to the frontal lobes of the brain, the areas behind the forehead that help us plan, control impulses and understand other people, causes gradual changes in personality and behaviour.

Unlike Alzheimer's disease, bvFTD does not usually start with memory loss. The first signs are changes in how a person acts, which can be hard for families to recognise as an illness.

Early signs of bvFTD

Symptoms usually begin between the ages of 45 and 65, although they can start earlier or later. Common early changes include:

• Loss of inhibition: acting impulsively or in socially inappropriate ways, such as making rude or insensitive comments to strangers
• Apathy: losing interest in work, hobbies, friends or family, which is often mistaken for depression
• Loss of empathy: seeming cold, selfish or unconcerned about other people's feelings
• Repetitive or compulsive behaviours: repeating phrases, gestures or routines, hoarding, or becoming fixated on timekeeping
• Changes in eating: craving sweet or fatty foods, overeating, losing table manners, or drinking or smoking more
• Problems with planning and judgement: difficulty organising, making decisions or managing money, often noticed first at work
• Neglecting personal hygiene

Day-to-day memory and the ability to find one's way around are often well preserved early on. Many people can still tell you the date and keep track of recent events.

Lack of insight

One of the hardest parts of bvFTD is that the person is usually not aware of the changes. They may not believe anything is wrong, and may refuse to see a doctor when family suggest it. The changes are usually first noticed by partners, family members or colleagues. This is not stubbornness: the parts of the brain that allow self-awareness are themselves affected.

Why bvFTD is often misdiagnosed

Because it starts in mid-life with changes in behaviour, bvFTD is easily mistaken for something else, including:

• Depression, especially when apathy is the main symptom
• Bipolar disorder or schizophrenia, particularly in younger people
• Obsessive-compulsive disorder, because of repetitive behaviours
• A "midlife crisis", stress or relationship problems
• Alzheimer's disease

On average, people with bvFTD are diagnosed three to four years after their symptoms began. If you are worried about someone, writing down specific examples of what has changed, and when, can help their doctor.

How bvFTD is diagnosed

There is no single test. A specialist, usually a neurologist or psychiatrist, will:

• Take a detailed history, ideally including someone who knows the person well, since the person may not recognise their own symptoms
• Use tests of planning, social understanding, language and behaviour. Standard memory tests can look normal in early bvFTD, so more specialised tests may be needed
• Arrange a brain scan, usually MRI, which may show shrinkage of the frontal and temporal lobes
• Arrange blood tests to rule out other causes
• Consider genetic testing, especially if there is a family history (see is frontotemporal dementia hereditary?)

A small number of people meet the criteria for bvFTD but do not get worse over many years, and their brain scans stay normal. Doctors sometimes call this a "phenocopy" syndrome. It is one reason specialists follow people over time before confirming the diagnosis.

How bvFTD progresses

bvFTD gets worse over several years, but the speed varies widely. Over time, many people develop language problems, memory difficulties and, in some cases, movement problems. In the later stages they need help with all daily activities. Our guide to the 7 stages of frontotemporal dementia describes how FTD typically progresses, including life expectancy.

Treatment and management

There is currently no treatment that slows or stops bvFTD, although clinical trials are under way. Care focuses on symptoms, safety and support:

• Medicines: some antidepressants and, with caution, antipsychotic medicines may help reduce difficult behaviours. Medicines used for Alzheimer's disease may not help in FTD, which is one reason an accurate diagnosis matters.
• Routine and environment: a predictable daily routine, fewer triggers, and calm redirection rather than argument often help.
• Food and safety: limiting easy access to sweets or alcohol, and keeping an eye on spending, driving and online activity, can prevent problems.
• Planning ahead: arranging power of attorney, finances and future care while the person can still take part.
• Support for carers: caring for someone with bvFTD is especially demanding, because it often starts at a younger age and changes the person's personality. Specialist support groups for FTD and younger-onset dementia can make a real difference.

Related pages

• 7 stages of frontotemporal dementia
• Primary progressive aphasia, the language-led types of FTD
• Frontotemporal dementia vs Alzheimer's