Robin Williams: Come Inside My Mind Documentary Promises Intimate Look At Comedian

"You're only given a little spark of madness and if you lose that, you're nothing."

A trailer for HBO's documentary Robin Williams: Come Inside My Mind promises an intimate look at the late comedian's life both on and off stage.

Featuring interviews with those who knew him best including Steve Martin, Billy Crystal and his son Zak, the documentary shows Williams as many of us remember him, an electric force of comedic nature.

The film premiered at Sundance Film Festival and director Marina Zenovich winds together interviews with comments from Williams himself, making him the documentary's main narrator.

"He was really comfortable onstage," Steve Martin can be heard saying in the trailer adding, "Offstage, I just felt he was holding himself together".

Williams died from suicide in 2014, and while initially it was thought he suffered from depression, Williams' widow Susan told People magazine the following year that the beloved comedian was actually suffering from a brain disease called Diffuse Lewy Body Dementia.

"It was not depression that killed Robin," she told People in 2015, the first public interview since the 63-year-old's death the year prior. "Depression was one of let’s call it 50 symptoms and it was a small one."

HBO is set to release Robin Williams: Come Inside My Mind on July 16.

If you need help in a crisis, call Lifeline on 13 11 14. For further information about depression contact beyondblue on 1300 22 4636 or talk to your GP, local health professional or someone you trust.

Featured image: Getty images.