Actually, the answer is yes - here's a medical condition called parasomnia pseudo-suicide to give some of us insomnia just thinking about it:
A man jumps out a fifth-story window. A woman marches into oncoming traffic. Another woman loads a gun and shoots herself. All appear to be open-and-shut cases of suicide, but, then again, maybe not. In rare cases, such deaths could be caused by something called parasomnia pseudo-suicide, experts say.
In other words: It’s possible to kill yourself in your sleep.
Melissa Dahl of The Body Odd blog has more: Link
More: NY Times article about the case of Tobias Wong, a promising designer who inexplicably hanged himself in the middle of the night
I wasn't making a specific comment towards the Wong example, and while I seriously doubt his partner of six years cares what I say on Neatorama, I won't bother to reply to that comment.
"A serious case of denial."
Tobias was my partner for six years. I was there when it happened. Please rethink your comment.
One day, I was listening to a girl who was with friends the previous night and accepted some psychedelic drug from a friend without even knowing which one it was (I told her that was stupid, and she agreed). While experiencing the effects of it she felt like she could fly, and considering that she lived in an apartment, as a precaution she died a string around her ankle and the other end to the leg of her bed. She woke up on her floor, laying flat facing the balcony door. There are things that go on in our heads that we aren't readily aware of.
A serious case of denial.