how to help him

I suppose I can't help my oldest son any more than my other two if he isn't willing to listen.  I know that he is very down right now because I can hear it in his voice.  Who wouldn't be in his position?  At 24 years of age ~ unemployed for about 3 months ~ he's in a deep rut and can't seem to get out of it.  He appears to be immobilized to really do anything and I believe he's very depressed.  I hope and pray that he will be able to get himself back on track but right now - it doesn't appear to me that this is going to happen anything soon.  
All his life he's been very engaged in life.  An honor student through high school and college ~ he was very involved in all kinds of activities - president of this club - president of that, volunteering in a Christian youth group ~ while maintaining his grades,  and holding down jobs and now........  he is struggling - big time.  
I'm doing my best to encourage him - suggesting small things he can try and tackle - and although he seems receptive to my ideas ~ I don't know.  I tried this before but it didn't work so I stopped.  I hope today he contacts his college and look into getting help at their job placement center.  I even sent him a link.  So we'll see.
About the job he lost ~ it was a low paying warehouse job.  He was fired!  He had lost that job before because of budget cuts and then was re-hired back into the same position a few months later.  He told us that his manager's boss became more involved in the daily operations because she was under a lot of stress trying to make up for the lay-offs they shouldn't have made to begin with.  He had his job down pat - but she had other ways of doing it - he says - so she was constantly knit picking.  So when he didn't show up to work one morning (this isn't him AT ALL) she had a good excuse to let him go.  His immediate boss really liked him and would have given him a break since he was always a very good worker.  
This depression isn't the first time it hit him - twice in college ~ ~ one because of a breakup with a girl ~ and the other (senior year had to drop a semester) ~ I believe he was struggling with what he was going to do with his life once he graduated.  And on top of that - he gained lots of weight.  Unlike my other bean pole boys - he is the complete opposite.  Poor guy.
For so long - (before high school) life in our family was so picture "perfect" - no issues - things just ran smoothly - the kids were well-behaved - teachers loved them - no problems.  Now? That's life.  Like most people - we all have something.   
Today I'm doing a bit better - can you tell?  Well - for one thing - our presentation is ready and I'm pleased with it.  Now I will just have to practice.