I think there must be something in your community that's available free or on a sliding scale for you since he's saying he wants to kill himself. Call your doctor, health department, or a suicide prevention hotline (you can use the ones below or look them up by state in the link.) Even if you don't believe your child will act on it, he probably needs to talk to someone. Depression can present as irritability. If it turns out he's ADHD, you should be able to get help with that once things are sorted out with the depression issue.
Suicide Prevention HotLine
�Call 1-800-SUICIDE / 1-800-784-2433
�Call 1-800-273-TALK / 1-800-273-8255
http://suicidehotlines.com/
