Ten years ago, Masahiko Sato was diagnosed with dementia. He is now battling to destigmatize the condition, which is affecting a rising portion of Japan's rapidly aging population. (Reuters)

Last year, more than 12,000 people suffering from dementia were reported missing in Japan, according to a Kyodo news agency story published in the Japan Times.

The report indicates that the total is a record — and an increase of more than 1,000 people from the year prior.

The figures come from the National Police Agency, which the news agency reports started to gather data on the issue a few years ago. According to the report, most of the missing person reports happened because a dementia patient wandered off.

The news agency reports:

• In 2015, 12,208 people who suffer from dementia were reported missing

• That's an increase of 1,425 people from the 2014 total

• Most of the dementia patients were found within the day or week that they went missing

Here's some background on dementia in Japan, via the Guardian:

With the over-64s already comprising just over a quarter of its 128 million population, Japan is at the forefront of devising ways to tackle the challenges posed by a super-ageing society, including the stigma attached to people with Alzheimer’s disease and other forms of dementia. The disorder affects 4.6 million people in Japan, with the number forecast to rise to 7 million – or one in five people aged 65 or over – by 2025.

News of the NPA figures comes a few months after the Supreme Court in Japan ruled in a case involving an elderly man who suffered from dementia. The 91-year-old man wandered onto train tracks and was killed. The railway company sued members of the deceased man's family, arguing that they should have been watching him more closely, according the Japan Times.

The court "dismissed the liability" for the man's family, that report stated.

“Families of elderly people have been watching this ruling … as if it were deeply related to their own nursing care,” lawyer Teruhiko Asaoka, who represented the family, told the Japan Times. "The ruling will truly be a relief for those families.”

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