The charity is looking to challenge the public perception that dementia only affects the over-65s.
The campaign, which will form the theme of Alzheimer's Awareness Week (3-9 July in England and Wales), will make the public 'think again' about what dementia means for sufferers, especially those under 65.
It will highlight the suffering of people in their 40s and 50s whose work is affected by mental illness.
It will also stress the problems that younger sufferers have to cope with, such as dependent children and financial commitments such as mortgages.
Middle-aged celebrities such as Graham Norton are backing the campaign, which will particularly target press aimed at readers in their 40s, 50s and 60s.
Case studies of people who have suffered dementia at a relatively young age will be sent to local and national newspapers, women's media and charity publications.
The charity will tell MPs that there is an 'urgent need to address the huge regional variations that exist in dementia services for younger people'.
The campaign is part of a move by the organisation to present itself as more than an Alzheimer's charity.
'Most younger people don't have Alzheimer's so this campaign will give us the opportunity to let people know that we provide help and support for all types of dementia, not just Alzheimer's,' said press officer Hannah Laslett.
There are 18,000 people in the UK under the age of 65 with dementia.