French playwright Florian Zeller's The Father shows how the world is a disorienting, psychological thriller for a man suffering from dementia.

Pangdemonium's staging runs from March 2 to 18 at the Victoria Theatre, with Lim Kay Siu in the role of Andre, a 70-year-old who finds his possessions missing and for whom family members seem to turn into strangers.

Tan Kheng Hua plays his daughter and caregiver Anne and the cast includes Janice Koh, Frances Lee, Emil Marwa and Keagan Kang in other roles.

In ageing Singapore, it is more important than ever for people to be able to speak freely about dementia and understand both the sufferer and caregiver's points of view.

But the script came first for director Tracie Pang, who helms Pangdemonium with her actor-husband Adrian. She was gripped by Zeller's writing, translated into English by Christopher Hampton.

"It's a very emotional read," she says. "It was very confusing as well, it feels like it's tricking your mind. What you read in the beginning doesn't work anymore and it's doing that on purpose.

"It looks at it from the sufferer's point of view and how the sufferer feels that everybody is trying to work against him. You never really think about it from that point of view."

Zeller wrote The Father for a French actor who was 88 years old at the time.

At 62, Lim is not as old as either the character or Zeller's muse, but he has noted some troubling changes in recent years.

He says ageing comes with hormonal changes that trigger moments of rage and anxiety.

"There's a fear of dementia. I'm on the road already, doubting my own capabilities and reviewing what I've made of my life," he says.

Tan, who plays Anne, won last year's Life Theatre Award for best actress for her role in the Pangdemonium play, Falling, as the mother and main caregiver to an autistic boy.

There are stark differences between the two roles, she says.

In Falling, the mother was in control.

Seeing a parent deteriorate is something else entirely. Roles are reversed between parent and child.

"The fact that dementia comes in your later life when there was a whole reality before that, that makes it so much harder," Tan says.

None of the three has been long-term caregivers for people with dementia. Their research involved working with the National Neuroscience Institute of Singapore and healthcare provider St Luke's, to speak with patients as well as their caregivers.

It was an eye-opening experience.

"When you meet people with dementia, they are lovely but, within a few minutes, they're asking the same questions again and again," Pang says.

"We can go away, but caregivers deal with it all the time."

Tan says: "For me, a very dominant theme in The Father is how precious every single moment is.

"We take our memories for granted, we take the moments that pass in our lives for granted and, when we lose them, we begin to realise how precious they are and how much we want to collect meaningful moments.

"That is a beautiful, bittersweet feeling."