I pity anyone who accepts without suspicion that Robin Williams, with all his wealth & resources, chose a belt as his exit method.

Autoerotic asphyxiation was my initial assumption, based on the belt and the family's tone.

However, the immediate and persistent "Robin was a glorious hero" campaign felt pre-scripted and extremely well coordinated, just like the Paul Walker campaign, which makes me wonder if Robin was murdered in this embarrassing manner to make the family reluctant to pursue any investigation (because they'd just be glad authorities are willing to keep, or failing to discover, the autoerotic asphyxiation secret).

Also, something else was sewn into the script; a 'heroic battle' with a very specific form of dementia (Lewy body).
I don't know the reason for this element being so heavily pushed. Maybe a bonus agenda to invest in a new LBD medication that was awaiting approval. Maybe just providing an excuse for inquisitive members of the general public regarding the bizarre suicide method. Maybe just a continuance of the general years-long, pharma-driven campaign to create a generation obsessed with labeling every quirk a mental illness that needs diagnosis & medication.