Number of New Zealanders with dementia expected to double to 170,000 in 30 years

The number of New Zealanders with dementia is expected to double in the next 30 years, to 170,000 people.

There'll be a big spike among Māori, Pasifika and Asian people especially - and advocates want more Government action.

Andrew and Pamela Allen's lives changed forever when Andrew was diagnosed with dementia last year.

"I can easily get lost. I can walk into someone else's apartment thinking it's ours," he says.

He's only 61.

"I know for a near certainty now how it's all going to end for me," he says.

Andrew has Alzheimer's, the most common type of dementia - it causes a loss of memory and cognitive skills.

"Losing my husband really, every day watching a bit more of him disappear and knowing it won't come back -  that's the hard thing," Pamela says.

He's one of about 70,000 Kiwis with dementia, but by 2050 that number will have soared to 170,000 - a 240 percent increase.

Over the same period dementia amongst Māori, Pasifika and Asian communities will triple to 35,000.

"There's going to be further poverty amongst these whanau so I'm very very concerned about our future," says Māori neuropsychologist and report co-author Makarena Dudley.

Māori and Pasifika are overrepresented in diseases that can lead to dementia - such as diabetes and heart problems.

"We need to do something about the inequities," Dudley says.

The economic cost of dementia is forecast to reach $6 billion by 2050 as the aging population grows.

"It's alarming, we're just not ready - at the moment services are woefully inadequate," Alzheimer's NZ CEO Catherine Hall says.

The Dementia Economic impact report is being launched at Parliament on Monday night with calls for more action from the Government.

Associate Health Minister Ayesha Verrall promises better support for dementia services - and to address health inequities.

"This is a big problem and only going to get worse," Hall says.

A problem 170,000 Kiwis like Andrew will be facing by 2050.