Experts believe the number of dementia sufferers will increase sharply in coming decades, mainly because of an ageing population, with one in three over-65s dying with the condition.
Law practioners are now concerned this could mean more wills wil
l be contested by family members who may argue that the sufferer did not know what they were doing when making changes.
Tom King of Northampton-based law firmTollers, which specialises in trust and probate claims, said: "Contested wills can quickly rip a family apart. And this is going to affect more and more Northampton families in the years to come. Where there's dispute within a family about the contents of a will, evidence must be produced before it can be contested.
"Sadly, evidence of a person having dementia when a will change is made can raise many issues."
There are 7,000 people with dementia in Northamptonshire, over half of who have Alzheimer's disease caused by diseases of the brain.
This figure is set to increase by almost 50 per cent by 2021.
The Alzheimer's Society has stressed the importance of people with dementia seeking an early diagnosis and planning for the future.
Gillian Shadbolt, manager of the Northamptonshire branch, said "It's very important that anyone who has dementia takes the time to plan for the future as early as possible.
"People do not necessarily need to seek legal advice to write a will. However, important checks must be carried out and documented to establish that a person with dementia 'has capacity' at the time it is made. It is important that people with dementia also have a lasting power of attorney. This will allow them to document wishes about their future care and appoint people to make health and financial decisions when they are no longer able to."
The Alzheimer's Society provides a national helpline on 0845 3000 336 and via its website:
www.alzheimers.org.uk
