Warning: This article discusses depression and mentions suicide.
Robin Williams' son has opened up about his late father's battle with "intense personal pain", as Sunday marked what would have been the acclaimed actor's 68th birthday.
In an interview with Good Morning Britain, 36-year-old Zak Williams looked back on his Oscar-winning father's devastating battle with depression and other health issues.
"As a family member and a child, you want to do everything you can to help soothe and ease what seemed to be intense personal pain," Zak shared on the show.
"It was sad to see someone who was suffering so."
The popular comedian and actor, known for his iconic roles as Mrs. Doubtfire and the Genie in Disney's Aladdin, died by suicide on August 11, 2014.
Williams says his father did not always share the extent of his internal suffering - something his family slowly noticed.
"I didn't know what I could do, or how I could be of the best support," Williams reflected. He revealed feeling a strong sense of "hopelessness" as he witnessed his father's struggle from the sidelines.
He said seeing his father continue to perform stand-up and act in projects, just to bring other people joy and laughter, was the hardest, most "heartbreaking" thing.
"He wanted to share his feelings of laughter and humour with the world... while he was suffering and struggling, he still went out and performed."
Zak Williams and his fiancee Olivia June welcomed their first child together on May 22. His son's name, McLaurin Clement Williams, pays tribute to the grandfather he never met. McLaurin was Robin Williams' middle name.
"Having to share him [with the world] was hard," Williams admitted.
"I admire him and love him so."
Where to find help and support:
Shine (domestic violence) - 0508 744 633
Women's Refuge - 0800 733 843 (0800 REFUGE)
Need to Talk? - Call or text 1737
What's Up - 0800 WHATS UP (0800 942 8787)
Lifeline - 0800 543 354 or (09) 5222 999 within Auckland
Samaritans - 0800 726 666
Depression Helpline - 0800 111 757
Suicide Crisis Helpline - 0508 828 865 (0508 TAUTOKO)