But, on the other hand, I was working with this other guy who was struggling, but seemed at peace with things, then out of nowhere he OD'ed on pain killers. Fortunately he survived, but it took everybody by surprise, even people who had been talking to him 30 mins. before.
Bam.
That's pretty textbook, actually. The earliest stages of recovery from a severe depression are actually the most risky when it comes to suicide. The person is still severely depressed, but their newfound strength gives them enough energy and focus to try something they might not have been able to before.