I think death by hypothermia would be a pretty good way to go. Eventually you stop feeling cold, right when it gets bad supposedly.
Sorry, not really about the topic at hand specifically. I just don't particularly care if prisons don't make sure their inmates, especially if going to be locked up for a long period of time, decide they'd rather die instead. Suicide is it's own choice.
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Not autistic, I think
Prone to depression
Have celiac disease
Poor motivation