Viggo Mortensen, who lost both his parents to complications surrounding dementia, pulled from his real-life trauma when writing his new movie "Falling."

In the film, which Mortensen also directed, he stars as John, a gay man, who takes in and cares for his conservative father, Willis (Lance Henriksen) who is battling dementia. 

The 62-year-old actor wasn't trepidatious about handling the sensitive subject because he lived it many times over while caring for his parents who died two years apart. 

"There's been a lot of [dementia in my family] and I've seen it over and over through the years... even in a caregiver capacity. So that helped me write the character of Willis and the way he relates to others," Mortensen told Fox News. 

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Mortensen added how "certain phrases, certain fragments of conversation and obviously dementia" from his family experiences inspired certain scenes.

Lance Henriksen as Willis and Viggo Mortensen as John in 'Falling.' (BRENDAN ADAM-ZWELLING / QUIVER DISTRIBUTION)

The Academy-award nominee explained how he wanted dementia portrayed in a very specific way on-screen.

"We, the observers, the caregivers can be confused, but they're the really seeing, feeling, and hearing these things. So it's tricky. You have to find ways you have to be flexible and you have to sacrifice your ego and not correct them," he reasoned. 

Mortensen's co-star Henriksen told Fox News that he didn't want to just simply "get caught acting" but rather "wanted to live it."

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The 80-year-old star added how he passed "no judgment" on the character because "if you live long enough, nobody gets through this life unscathed."

Mortensen directing Henriksen in a scene from 'Falling.'  (BRENDAN ADAM-ZWELLING / QUIVER DISTRIBUTION)

Mortensen boiled the film down to one simple theme: communication or lack thereof. 

"It's a movie that's really about communication and the problems of communication," he said of the dynamic between the father and son. 

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He added, "It was beautiful to feel that everybody [on-set] was personally and emotionally involved in what we were doing."

"Falling" premieres in theaters and VOD on Feb. 5th. 

Fox News' Ashley Dvorkin contributed to this report.