Disabilities

Hi, my name is Danny. My brother Nick has a mental disabilitie to.He has ADHD. My brother is a very smart kid but but he needs a little self control and so do I but i'm working in it with my thearapist, my parents and Mrs.Crozzoli. Can a mental disabilitie such a ADHD be related to a physical disabilitie? Me and my brother are very athletic kids and love to use up energy.

Thank You,
Danny