Chris Hemsworth and his dad's bittersweet Gold Coast appearance

It's not unusual for Hollywood heartthrob Chris Hemsworth to have wife Elsa Pataky and members of his family supporting him at the premiere of a new project.

But the "emotional" screening of his new National Geographic documentary on the Gold Coast on Wednesday was different, and more poignant than those before.

That's because Chris Hemsworth: A Road Trip to Remember sees the Thor star take his dad Craig on a road trip into their past, as they attempt to halt the progression of Craig's Alzheimer's diagnosis.

The father and son posed for photos on a yellow carpet at the screening in a bittersweet moment, as the family attempts to shine a light on the disease impacting millions around the globe.

Family matriarch Leonie Hemsworth was also there, in a black outfit to match her husband.

Pataky wowed in a vibrant green maxi dress, paired with a gold accessories, including a chocker, armband, platform heels and clutch.

Chris wore a coffee-coloured three piece suit for the event, which was also attended by the couple's three children India, Tristan and Sasha.

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His famous brothers Luke and Liam were also there with their respective partners – wife Samantha Hemsworth and fiancee Gabriella Brooks.

Luke and Sam's three children Holly, Ella and Harper were also on hand to support their uncle and grandfather.

The one-hour documentary, which centres on a motorcycle road trip, "highlights hopeful, science-backed tools in the fight against memory loss and cognitive decline".

It explores "the scientific impacts behind social connection and reminiscence therapy as methods to stimulate mental activity, evoke memories and improve well-being".

Also appearing in the documentary is UNSW clinical psychologist Dr. Suraj Samtani.

The expert from the university's Centre for Healthy Brain Aging says "all the memories get unlocked with emotion".

"Let's say if you're remembering your graduation, you'll remember feeling happy about it, but you won't feel the same happiness you felt at that time," he explained to People magazine.

"Whereas a fear memory, you will actually feel the original fear you felt at that time, and the same with these adrenaline memories."

Samtani helped the Hemsworths with the reminiscence therapy and says "it was really effective".

"I saw him initially being really reserved, really unsure where he was, what was going on," the expert told the publication.

"And by the end, as you can see in the documentary, he's laughing, he's smiling, he's remembering all these key memories from his past, and he's really confident.

"I think that that for us was a success to get him out of his shell and feeling more like himself."

Chris Hemsworth: A Road Trip to Remember is available to stream on Disney+ from November 24.

Nine Entertainment Co (the publisher of this website) owns and operates the streaming service Stan.

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