This was a part of my journey with my exAH.
We suspected for a long time that he was living with this. When he had an affair, and I started to actually deal with the alcohol, he started to finally deal with this.
This book helped him immensely
You Mean I am Not Crazy, Lazy or Stupid? by Kate Kelly and Peggy Ramundo
This website helped me out immensely (I think he said it helped him also but I used this more after we split).
ADHD and Marriage | by Melissa Orlov & Dr. Ned Hallowell<br>Learning to thrive in your relationship
My personal experience is that the two people in my life that have been closest to me that I believe struggle with problem drinking, have ADD. Sometimes I don't know what is what in terms of behaviors etc. Regardless of their stuff I have responded similarly to both by overdoing, rescuing etc.
My exAH got tested as an adult and the testing showed that he was living with it. He went from his primary MD to a specialist (but the scripts were ordered by the primary). I only lived with him for four months after him starting treatment but it made a huge difference in his life.