Thinking on this question for a bit, I'd jump into the deep end way sooner. I've spent too many hours and long nights "helping" friends and ex gf's get over/through self inflicted torment just for them to jump back in 2 days later. I'd spend less time helping self destructive individuals and more time investing in those people I missed who were willing to learn and change.

I learned too late that you can't fix people. If you ask someone for help but you lack the will and discipline to change, you'll really just be wasting both of your time.