I think my husband has ADHD but he won't talk about it

My husband and I have been together for 10 years and married for 4.  I am a teacher and have been educated on the aspects of ADHD and have always felt that my husband exhibits all of the signs.  Anytime I try to talk to him he gets very angry and feels that I am only saying these things to hurt his feelings.  I am really worried about him, especially now that we have a 2 month old son.  Our marriage and relationship are greatly suffering because of his condition.  I am desprately seeking advice on how to approach this delicate topic with him so that we can get the help he greatly needs.