Viggo Mortensen has said his own experience of caring for his dementia-suffering parents set the “template” for his directorial debut.

The Lord Of The Rings actor wrote, directed and stars in Falling, about a middle-aged gay man whose conservative and homophobic father Willis, played by Lance Henriksen, starts to develop a form of the disease, forcing him to sell the family farm and move to Los Angeles to live with John and his husband.

It is Mortensen’s first time in the director’s chair after more than three decades in the film industry.

The 62-year-old Danish-American actor, who was born in New York, said his own experience of dementia, which has been prevalent in his family, informed how he portrayed the illness on screen.

He told the PA news agency: “I had a lot of experience with it in my family, both of my parents, three of my four grandparents, aunts, uncles, my stepfather.

“And in some cases, like my stepfather and both my mother and father, I was up close and constantly there, and sometimes even in a caregiving role.

“That helped me to write the character and to write the relationships, the template for what we were going to tell.

“The relationship with the character Lance plays, Willis, with John, his son, my character, and with Laura Linney’s character, Sarah, his daughter.

“And we tried through the acting, but also through all the things you can do with filmmaking – the use of images, in terms of memories, sound and where sound is placed and mixed – to get across to some degree, sometimes the point of view of the person suffering from that.

“In other words, that’s not a confused person, that’s a person who is actually seeing and feeling these things – the confused ones are the observers, usually, in my experience.

“Not the way it’s usually depicted I suppose… the best impersonations of that, where you are shown a confused person or a point of view of someone who’s confused.

Viggo Mortensen
Viggo Mortensen (Ian West/PA)

“We wanted to do something different, closer to what I’ve experienced.

“From my point of view, that’s what I was looking at.”

Mortensen said he had previously been unable to secure funding for his directorial projects.

He said: “I’ve been wanting to try my hand at directing for a long time. The reason it was Falling that became my first movie as a director is because that’s the one I found the money for, finally, after a few tries.

“But I had written other screenplays and I think the first time I tried was about 24 years ago, to get a movie made.

“But I never managed to get the financing together for various reasons, and fortunately, we finally were able to make this one, and I’m very happy it was this one and I’m very happy that I got to do it with Lance.”

Falling is out in cinemas now.