Frontotemporal dementia is a group of diseases in which parts of the brain (the frontal and temporal lobes) shrink, or atrophy, causing changes in personality and behaviour. People with frontotemporal dementia may display unusual behaviour, such as a lack of caring and lack of inhibition.

In one type of frontotemporal dementia, called Pick's disease or Pick's complex, abnormal structures called Pick's bodies develop in brain cells. Pick's disease is rare but can run in families.

People with frontotemporal dementia may:

• Not express any caring for others.
• Not attend to personal hygiene.
• Say rude things to others, expose themselves, or make sexually explicit comments, or exhibit other socially inappropriate behaviour.
• Be obsessed with repetitive routines or develop unusual food obsessions, such as eating the same kind of food or eating in the same restaurant repeatedly.
• Have difficulty understanding words and naming objects.

Frontotemporal dementia cannot be reversed. Doctors may treat its associated behavioural problems with antidepressants and other medicines.