adoption tax credit

We adopted a 15 year old boy that is designated as a special needs child due to his age and his struggle with ADHD. I have read IRS pub 968 and it appears that we do qualify for the special needs adoption tax credit. However, I am confused as to what form to use to file for the tax credit. I believe it was form 8839 that is usually used. But I don't see anything regarding the special needs case. Anyone know of a different form? Thanks