I think my friend has depression...

First off it is really good that your friend has at least one person he can talk to. Loneliness is a terrible thing and it can very often lead to depression, then the depressed person feels unable to go out and talk to people and so the vicious cycle continues. Invite him out whenever you can, don't be deterred if he says no. Suggest he hangs out on the internet, there are always forums and chatrooms where you can find people to share your interests. Finally, emphasise that if he does go to see his doctor then they will help him feel better, and there is no need for anyone to suffer like he is suffering. Good luck to you both.

I also had gone under acute depression few years back due to financial losses with the result it caused utter confusion in my mind,didnt know what and where to start any work,it was a horrible condition.On somebody's advice I consulted a psychiatrist who gave me anti-depressants which worked a lot,I could think clealy,would do breathing exercises and other yoga asans,started to change my thinking in a positive manner...what I mean to say is that if possible you consult a psychiatrist and get anti-depressant pills for him which may work for him and he will start thinking ways to cope up with his depression.