The following deals with suicide, which may be triggering for some readers. If you're struggling, support is available 24 hours a day through Lifeline. Call 13 11 14.
Robin Williams' work is considered some of the best ever committed to film: from his Oscar-winning performance as Dr. Sean Maguire in Good Will Hunting, to radio DJ Adrian Cronauer in Good Morning Vietnam and Aladdin's beloved Genie.
Throughout his four-decade career, he danced deftly between rapid-fire riffs, slapstick and nuanced drama.
But in the years leading up to 2014, those around Williams noticed a change in him.
The lines didn't come quite as quickly, the jokes didn't land as cleanly. His movements seemed slower, more deliberate.
On August 11 that year, the 63-year-old said goodnight to his wife of three years, Susan Schneider, and retired to his room. The couple slept separately due to Williams' crippling insomnia.
"As we always did, we said to each other, 'Good night, my love,'" Schneider said in the 2018 biography, Robin.
"He seemed like he was doing better, like he was on the path of something."
By the following morning, the father of three had taken his own life.
The 'terrorist' within Williams' brain.
After his death, the coroner discovered that Robin Williams had unknowingly lived with a form of dementia known as Lewy body disease.
In a new documentary, Robin's Wish, Schneider recalls doctors inviting her in to discuss the results.
"I was relieved it had a name. Robin and I had gone through this experience together, really being chased by an invisible monster. And it was like whack-a-mole with the symptoms," she said. "I left there with a name of the disease, the thing that Robin and I had been searching for."
Lewy body disease is a common neurological ailment that involves the degeneration and death of nerve cells in the brain. It occurs due to an abnormal buildup of a protein that affects movement, thinking and behaviour.
According to Dementia Australia, symptoms include extreme confusion, difficulty with concentration and attention, difficulty judging distances, visual hallucinations, tremors, and fluctuations between lucid and disoriented mental states.
In Australia, the disease affects roughly 100,000 people and is one of the most common causes of dementia, though remains relatively little known.