Good question! I get the feeling from reading the two links below that while all people with adhd have EFD. You can have EFD and not adhd since the EFD can be a learning disorder not due to adhd. I hope these help. Since knowing the difference does amount in treatment differences.
First link might be the best.
https://www.additudemag.com/executive-function-disorder-adhd-explained/
Second is more on ways to treat.
https://www.additudemag.com/slideshows/what-are-adhd-executive-functions/
Ok, this is interesting. took one last look. This link talks about executive functioning issues and never once mentions adhd.
https://childmind.org/article/child-has-executive-function-issues/
Glad I kept looking. Finally one that says, "ADHD is an official diagnosis. Executive functioning issues is not. It’s a term that refers to weaknesses in the brain’s self-management system. Also, trouble with executive function isn’t just a problem for kids with ADHD. Many kids with learning issues struggle with one or more of these key skills."
from..... https://www.understood.org/en/learning-attention-issues/child-learning-disabilities/executive-functioning-issues/difference-between-executive-functioning-issues-and-adhd?cm_ven=ExactTarget&cm_cat=12.2.2014+Organization+Tips&cm_pla=Salesforce.com+Managed+Subscribers&cm_ite=https%3a%2f%2fwww.understood.org%2fen%2flearning-attention-issues%2fchild-learning-disabilities%2fexecutive-functioning-issues%2fdifference-between-executive-functioning-issues-and-adhd&cm_ainfo=&utm_campaign=newsletter&utm_source=generalnews&utm_medium=email&utm_content=12/5/2014&&&&
Hope this helps. Please ask if you have any more questions. Hope this wasn't too much info!
Those were great reads. I also passed them on to a friend of mine. I'm battling some 504 stuff right now with my son. Sigh. The older kids get, the trickier some things are! It would almost be easier if my son was a terrible student to get cooperation! Ugh. Disappointed!!