Every situation can be broken down to simple choices, all you have to do is remove al the emotional content and there it is.
The real questions here are
1 Can you help him alone?
2 Do you know someone who can?
The main thing you have to ask your self here is
Which is more important, helping him out or keeping him as a friend?
Would you prefer an emotionally well adjusted friend or one who is dependant on you as a shoulder to cry on?
Would you prefer an emotionally well adjusted person leaning on your shoulder?
No moral judgement here, you know the full details of the situation but just try removing all emotion and looking at it logically and see if a solution presents itself.