Mental torture? Are you kidding me ? Having depression does not award you a "get out of prosecution free" card. Might as well charge the friends and family who knew he was suicidal -- it was on his damn blog! -- for not getting him the help he needed. That's only slightly less ridiculous than your over-the-top idea.
The guy had serious issues, blaming a prosecutor for doing their job is ridiculous. The guy broke the law, period. Don't do the crime if you can't do the time.
“There is no such thing as a weird human being. It’s just that some people require more understanding than others.” - Tom Robbins