Has there been any studies linking NCS or POTS to ADHD or ADD? My 13 year old son has been diagnosed with NCS, but I think it may be POTS. The doctor treating him said the two terms are almost interchangeable, but I have read different. My issue is that he also has other issues including migraine headaches, frequent nausea and vomiting, and ADHD (more ADD). He is having a lot of problems with attention and concentration at school. I am trying to get help from his school, but they have to do their "testing" before he can qualify. Does anybody know if there is a link between these issues that can support my effort to get help for my son in school?