Around 4,000 new cases of dementia are diagnosed in Ireland each year.
A new report says there are over 41,700 people with the condition, of whom 26,000 live at home, and the numbers are expected to more than treble over the next 30 years.
It says early diagnosis, and sometimes any diagnosis, is the exception rather than the rule
The report says that Irish GPs, like their European counterparts, experience difficulty in diagnosing the illness and would welcome more training and resources.
It recommends more emphasis on primary prevention and ways of avoiding or delaying the illness, particularly through reducing health disease and stroke.
Most of those with dementia living at home probably do not have a formal diagnosis.
The report was funded by Atlantic Philanthropies and was published today at a conference at in Dublin.
The conference discussed the development of a national dementia strategy, which has been promised by the Government in 2013.
The report says there are an estimated 50,000 family carers looking after someone with at least one of six specified symptoms of dementia.
It suggests that around two-thirds of all long-stay residents have dementia, with many of those again not having a formal diagnosis.
The cost of dementia in Ireland is put at nearly €1.7bn a year, 48% of which is attributable to informal care provided by family and friends.
A further 43% is accounted for by residential long-stay care, while other formal health and social care service contribute just 9% of the total cost.
The report says Irish home care services are not underpinned by legislation, nor are they provided on a statutory basis.
It also calls for greater public awareness about dementia.
The principal investigators for the research were Professor Suzanne Cahill of Trinity College Dublin and Professor Eamon O'Shea of NUI Galway.
