Matthew Carney reported this story on Friday, May 23, 2014 08:19:00

CHRIS UHLMANN: Japan has the world's oldest population. One-quarter of its 127 million people is aged 65 or over.



Now it's facing a dementia epidemic. Nearly five million people live with the condition and thousands are going missing from their homes and carers every month. Families say the government response to the crisis has been inadequate.



North Asia correspondent Matthew Carney reports.



MATTHEW CARNEY: In Japan's second biggest city Osaka, Atsuko Hajihata is frantically looking for her missing grandfather, Akinori Matsuyama. For the last several months she's been handing out leaflets on street corners and train stations, asking people to contact her if they see her grandfather.



He walked out of the family home in January and has not been seen since and Atsuko thinks he has dementia.



ATSUKO HAJIHATA (translated): I feel nervous. I've heard that bodies of drowned people have been found. But maybe he's being looked after by people. I still have hope I'll find him.



MATTHEW CARNEY: Some of the missing turn up in mental institutions or aged care homes. An unidentified man has been living in a nursing home in Osaka after being rescued from a busy highway two years ago. He has severe dementia and does not know his name or where he came from. And there is no information that can help identify him.



(Sound of woman speaking)



He's carer asks him if can remember anything but the man does not reply.



Tragically many of the missing are found dead. Kenzo Yoshizawa left his home while his wife was preparing dinner. She wrote his name and address on his shoes but Kenzo left in his scandals. Three weeks later he was found frozen to death beside a river just 500 metres from his home. His wife believed he would return.



KENZO YOSHIZAWA'S WIFE (translated): I have regret and feel sorry that I wasn't able to find him.



MATTHEW CARNEY: It's hard to get exact figures of how many people with dementia go missing but police estimates for 2012 are about 10,000. Experts say it's much more and the problem is only going to get worse.



Kumiko Nagata works at one of Tokyo's oldest and biggest aged care facilities.



KUMIKO NAGATA (translated): In Japan people over 65 exceed 25 per cent so the number of people missing with dementia will increase rapidly. And these days old people aren't living with their families, they often live alone or as elderly couples where both might have dementia so they don't realise if one goes missing.



MATTHEW CARNEY: There is a network for missing person but only about 10 per cent of local governments are using it. Most want a new system with much greater cooperation between police and government agencies.



In the meantime communities are taking matters into their own hands. On the outskirts of Tokyo the volunteer group Missing Person Search has been set up. Hiroshi Tahara who runs the organisation was a police officer for 25 years.



HIROSHI TAHARA (translated): Police don't actively search and only get involved if there has been an unusual death.



MATTHEW CARNEY: Families want practical measures put in place like GPS devices in shoes so people living with dementia can be easily found.



This is Matthew Carney reporting for AM.