Robin Williams' son admits he struggled to watch on while his late father was "suffering and struggling".
The iconic actor and star of such films as Good Morning Vietnam and Mrs Doubtfire took his own life in 2014 at age 63.
Now his son Zachary has revealed he had a hard time and felt helpless seeing his dad continue to work while he was experiencing "intense personal pain".
Speaking last week during an appearance on UK television show Good Morning Britain, the 36-year-old reflected on his late father's life and his long-running struggle with mental health.
"For the most part he was very good at putting his personal struggles aside and soldiering on," he explained.
"When it did show through it was sad to see someone who was suffering so. As a family member and child you want to do everything you can to help soothe and ease what seemed to be a really intense personal pain.
"There were times when it felt like there was helplessness from my part, I didn't know what I could do, or best support. Amongst those people close to him, we all love him so and found it difficult. He wasn't always open to sharing his personal pain and struggle. We noticed that over a period of time."
Zachary, whose mother is Robin's ex-wife Valerie Velardi, admitted he found it "heartbreaking" watching his dad put on a happy face and keep other people entertained when he knew the extent of his inner turmoil.
"Being Robin Williams' son was wonderful in so many ways. Having to share him with the world was hard at times.
"When he was having challenges and going through certain things it was heartbreaking because he still went out and wanted to share his feelings of laughter and humour with the world. And, while he was suffering and struggling, he still went out and performed. I admire him and loved him. Having to share him was hard."
More pain was to come, he said, when the family had to reveal news of his father's death to the public.
"Sharing the grieving process with the world was hard. At times it was hard to differentiate what involved private grieving, and experiencing that loss, versus public grieving and experiencing that type of community interaction and communicating. I wasn't prepared.
"It was challenging. But I'm very grateful for the outpouring of love and support that continued … Here we are almost five years later. I feel the massive impact and difference he made."
WHERE TO GET HELP:
• Lifeline: 0800 543 354 (available 24/7)
• Suicide Crisis Helpline: 0508 828 865 (0508 TAUTOKO) (available 24/7)
• Youth services: (06) 3555 906
• Youthline: 0800 376 633
• Kidsline: 0800 543 754 (available 24/7)
• Whatsup: 0800 942 8787 (1pm to 11pm)
• The Word
• Depression helpline: 0800 111 757 (available 24/7)
• Rainbow Youth: (09) 376 4155
• CASPER Suicide Prevention
If it is an emergency and you feel like you or someone else is at risk, call 111.
- Additional reporting Bang Showbiz