Why Behaviour Can Change So Dramatically
Understanding sudden behavioural changes in FTD and what causes them
For many families, the most confusing part of frontotemporal dementia is not forgetfulness. It is the sudden and sometimes dramatic change in behaviour. A person who once behaved politely may begin saying things that feel rude or insensitive. Someone who always respected social boundaries may suddenly ignore them.
The Brain’s “Brake System”
In everyday life, most people constantly regulate their behaviour without thinking about it. We pause before speaking. We adjust our tone depending on who we are talking to. We avoid saying things that may hurt others.
These abilities depend heavily on the frontal parts of the brain. You can think of these areas as a kind of brake system. They help us slow down our impulses and choose appropriate behaviour.
When frontotemporal dementia affects these regions, the brain’s ability to regulate behaviour becomes weaker. As a result: impulses may appear quickly, social filters may disappear, and behaviour may become more direct or uninhibited.
Loss of Social Awareness
Another important function of the frontal brain systems is social awareness. This ability helps us recognise how our behaviour affects others. For example, we normally notice facial expressions, tone of voice, and body language. These signals help us adjust our behaviour in real time.
When this system is affected, the person may not notice these signals as clearly. They may not realise that someone feels embarrassed, hurt or uncomfortable. From the outside, this can look like a loss of empathy. But the change is often related to the brain’s ability to interpret social cues.
Communication Example
When the person says something inappropriate in public:
What helps:
- Remain calm
- Gently change the subject
- Guide the person to another activity
- Avoid drawing attention to the situation
What often makes it worse:
- Correcting the person publicly
- Expressing strong anger or embarrassment
- Arguing about social rules in the moment
Emotional Reactions in Families
The behavioural changes in frontotemporal dementia often trigger strong emotions in families. Common reactions include shock, embarrassment, anger, sadness, and guilt. Partners may feel hurt by the person’s lack of empathy. Children may feel embarrassed in social situations.
These reactions are natural. Frontotemporal dementia challenges many of the expectations we have about relationships and personality. Recognising the illness behind the behaviour can help families begin to adjust their expectations.
———————————————
This article is part of the series:
→ Frontotemporal Dementia Care Strategies
A collection of practical guides for families living with FTD — explaining behaviour changes and what helps in everyday situations.
See all articles in the series here.