ADHD and looking people in the eyes

While having a conversation, do you find it easy or anxiety-inducing to maintain eye contact with the person you are speaking with? Personally, I hate looking people in the eyes; I just can't. It just gives me an inexplicable uncomfortable feeling. I have trouble focusing on what the other person is saying if all my mental energy goes into trying to maintain eye contact.

I know people on the autism spectrum find it difficult to make eye contact. This might be one reason why my psychologist thought for a long time that I had Asperger's rather than ADD. I would, therefore, like to ask if this is common with people who have ADHD as well. Do you find it easy to look people in the eyes?