I would talk to him about how feeling that way is his depression and is not reality. Tell him that those feelings will pass. Teach him ways to make himself feel better by playing a computer game, watching TV, or whatever he likes to do especially things he can do on his own. I don't know anything about focalin but if that really could be playing a part, I would tell him that sometimes the medications can have a strange effect and that if it continues the medication will be discontinued (if true) and another one tried.
My daughter has occasional depressed moods and I am trying to teach her what causes it and how to get through it without causing further problems for herself. It will continue to be a problem for her at times and she needs to know how to cope with it as an adult.
If he won't talk to you then, you might have to wait until he's calmed down some. I tend to say it at the time anyway, thinking even if she acts like she isn't listening, she is getting the message.
